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Volume 5 Issue Number 2 ISSN 1932 - 4731 Table of Contents Pg. 88: Guest Editors’ Comments - M. N. Hegde & Raymond Weitzman Pg. 90: Language and Grammar: A Behavioral Analysis - M.N. Hegde Pg. 114: Verbal Behavior by B.F. Skinner: Contributions to Analyzing Early Language Learning - Scott F. McLaughlin Pg. 132: The Bases for Language Repertoires: Functional StimulusResponse Relations - Raymond S. Weitzman Pg. 150: Behavioral vs. Cognitive Views of Speech Perception and Production - Henry D. Schlinger, Jr. Pg. 166: Speech and language assessment: A verbal behavior analysis - Barbara E. Esch, Kate B. LaLonde, & John W. Esch Pg. 191: Effects of a Speaker Immersion Procedure on the Production of Verbal Operants - Nirvana Pistoljevic, Claire Cahill, & Fabiola Casarini The Journal of Speech - Language Pathology and Applied Behavior Analysis VOLUME NO. 5, ISSUE NO. 2 ISSN: 1932 - 4731 Published: May 13, 2010 Publisher’s Statement The Journal of Speech-Language Pathology and Applied Behavior Analysis (JSLP-ABA) is published by Dr. Joseph Cautilli and BAO Journals. It is a peer-reviewed, electronic journal intended for general circulation in the scientific community. The mission of this journal is to provide a forum for SLP and ABA professionals to exchange information on topics of mutual interest. These topics may include, but are not necessarily limited to support for disorders of prelinguistic communication, speech perception/production, oral language and literacy, speech fluency, and voice. They may also address issues pertaining to accent reduction, culturally-based language variations, and augmentative-alternative communication. JSLP-ABA welcomes articles describing assessment and treatment efficacy research based on detailed case studies, single -subject designs, and group designs. Also encouraged are literature reviews that synthesize a body of information, highlight areas in need of further research, or reconsider previous information in a new light. Additionally, this journal welcomes papers describing theoretical frameworks and papers that address issues pertaining to SLP-ABA collaboration. All materials, articles, and information published in JSLP-ABA are peer-reviewed by the review board of JSLP-ABA for informational purposes only. The information contained in this journal is not intended to create any type of patient-therapist relationship or representation whatsoever. To receive a free subscription to JSLP-ABA, please send an e-mail to [email protected]. Include your name and the email address in the body of your e-mail; and type “subscribe-SLP-ABA” in the subject field. When your email is received, your name will be added to the subscription list. You will then automatically receive notice of publication of each new issue through an e-mail containing a hyperlink to the latest issue. All rights are reserved. The Journal of Speech – Language Pathology and Applied Behavior Analysis may be freely accessed, downloaded, and distributed free of charge. If you wish to sell our journals or charge a fee for access to our journals, you need to obtain the express prior written permission of the copyright holder. For uses requiring permission, contact Joseph Cautilli, Ph.D., BCBA. All information contained within is provided as is. The SLP-ABA journal, its publisher, authors, and agents, cannot be held responsible for the way this information is used or applied. The Journal is not responsible for typographical errors. Mission Statement The mission of the Journal of Speech-Language Pathology and Applied Behavior Analysis (JSLPABA) is to provide a forum for SLP and ABA professionals to exchange information on topics of mutual interest. These topics may include (but are not necessarily limited to) support for disorders of prelinguistic communication, speech perception/production, oral language and literacy, speech fluency, and voice. They may also address issues related to accent reduction, culturally based language variations and augmentativealternative communication. JSLP-ABA welcomes articles describing assessment and treatment efficacy data based on detailed case studies, single -subject research design, and group designs. Also encouraged are literature reviews that synthesize a body of information, highlight areas in need of further research, or reconsider previous information in a new light. Additionally, this journal welcomes papers describ ing theoretical frameworks and papers that address issues pertaining to SLP-ABA collaboration. JSLP-ABA is viewed as a primary source of information for speech-language pathology (SLP) professionals and professionals in applied behavior analysis (ABA) who support individuals of all ages with communicative disorders. The contents of this journal are intended to meet the interest of these professionals for information to support evidence-based practice. JSLP -ABA is also intended to serve as a vehicle to encourage collaboration between these SLP and ABA professionals. Submission Information for Authors Overview All papers must be submitted in MS Word DOC format to the Lead Editor (Dr. Joseph Cautilli) via e-mail at [email protected]. Papers may be submitted at the initiative of an author or in response to an invitation from the Lead or Associate Editors. All submissions are peer-reviewed and must be accompanied by a signed Assignment of Rights (AOR) form. A link to the AOR form is at the bottom of this page. After peer review and follow-up, all articles are copyedited. Authors have an opportunity to review and approve their manuscript prior to publication. Once approved, authors are responsible for all statements made in their work, including changes made by the copy editor prior to approval. Content To be considered for publication, articles must address topics of mutual interest to SLP and ABA professionals. These topics may include (but are not necessarily limited to) support for disorders of prelinguistic communication, speech perception/production, oral language and literacy, speech fluency, and voice. They may also address issues related to accent reduction, culturally-based language variations and augmentative-alternative communication, SLP-ABA collaboration. Articles may report original research, descriptions of theoretical frameworks, literature reviews, treatment critiques, and tutorials. Peer Review Process All submitted manuscripts are reviewed initially by the Lead Editor. Manuscripts with insufficient priority for publication will be rejected promptly. Other manuscripts will be sent to the Senior Associate Editor, who will distribute them to editorial consultants with relevant expertise. The editorial consultants will read the papers and evaluate (1) the importance of the topic addressed by the paper; (2) the paper’s conformity to standards of evidence and scholarship; and (3) the clarity of writing style. Comments provided by the editorial consultants will then be provided to the author(s) for follow up. 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If graphics, figures and tables are used, they must be created in *.jpg or *.bmp format. No Excel graphs will be accepted. Graphics, figures, and tables, if used, may be embedded in the body of the manuscript or they may be submitted in a separate MS Word document. If the latter option is chosen, then author(s) must indicate clearly the intended location of each item (graphic, figure, table) within the manuscript so that the copy editor can make the insertions. Individual graphics, figures, and tables, when used, may not be larger than one page. The caption for a table must be printed above the table. The caption for a figure must be printed below the figure. In the references section, please use italics where APA style would allow underlining (e.g., the titles of journals and books). Author contact information must include the following 4 elements for each author: name, mailing address, phone, and e-mail. Manuscripts must be saved and submitted in MS Word “DOC” format. When there is a conflict between the requirements of APA style (see below) and the formatting rules listed here, the formatting rules will supersede the APA requirements. Manuscript Style Requirements: • • • • With the exception of the above (formatting) guidelines, authors must write their manuscripts in a style that is consistent with the Publication Manual of the American Psychological Association (APA Manual) (5th edition). A copy of this manual may be ordered at http://www.apastyle.org/ Consistent with APA style, authors must use non-sexist language. Please refer to Table 2.1 in the APA Manual for “Guidelines for Unbiased Language.” Also consistent with APA style, authors must use person-first language for referring to individuals with potentially stigmatizing characteristics. Person-first language requires an author to name the individual first, followed by descriptive information (e.g., "child with autism") rather than to use an adjectival form (i.e., "autistic child") or a nominal form (i.e., "the autistic"). As noted above: When there is a conflict between the requirements of APA style and the formatting rules listed in the above section, the formatting rules will supersede the APA requirements. General Guidelines for Preparing Abstracts: The following general guidelines must be honored to insure that JSLP-ABA will be accepted into the major psych databases. (See PsychINFO website: http://www.apa.org/psycinfo/about/covinfo.html) • • • • • • An abstract may not exceed 960 characters and spaces (approximately 120 words). Characters can be conserved by using digits for numbers (except at the beginning of sentences); by using well-known abbreviations; and by using the active voice. Begin the abstract with the most important information, but don’t repeat the title. Include only the four or five most important concepts, findings, or implications. Embed as many key words and phrases in the abstract as possible. Include in the abstract only information that appears in the body of the manuscript. For the sake of clarity, define all acronyms and abbreviations except for measurements; spell out the names of tests; use generic names for drugs (when possible); and define unique terms. • • Use the present tense to describe results with continuing applicability or conclusions drawn and the past tense to describe variables manipulated or tests applied. As much as possible, use the third person rather than the first person. Abstracts for Empirical Studies: Abstracts for empirical studies are also generally about 100 to 120 words in length. They should include the following information: • Problem under investigation (in one sentence) • Pertinent characteristics of participants (e.g., number, type, age, sex, genus and species) • Experimental method, including apparatus, data-gathering procedures, and complete test • Names and complete generic names and dosage and routes of administration of any drugs (particularly if the drugs are novel or important to the study) • Findings, including statistical significance levels • Conclusions and implications or applications Abstracts for Literature Reviews and Theoretical Articles Abstracts for review or theoretical articles are generally about 75 to 100 words in length, and they include the following information: • The topic (in one sentence) • The purpose, thesis, or organizing construct and the scope (comprehensive or selective) of the article • Sources used (e.g., personal observation, published literature) • Conclusions Thank you! 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For more information, or place an ad, contact Halina Dziewolska by phone at (215) 462 -6737 or e-mail at: [email protected] The Journal of Speech - Language Pathology and Applied Behavior Analysis ISSN: 1932-4731 Senior Editor Editorial Staff Joe Cautilli, Ph.D., BCBA Co-Lead Editor Mareile Koenig, Ph.D., CCC-SLP, BCBA Co-Lead Editor Douglas Greer, Ph.D. Associate Editors Leslie Cohen, Ph.D. Joanne Gerenser, Ph.D., CCC-SLP Elizabeth Grillo, Ph.D., CCC-SLP Caio Miguel, Ph.D. Editorial Board Christine Barthold, Ph.D., BCBA Vince Carbone, Ph.D. Jenn Cronin, M.Ed. Brian Cowley, Ph.D., BCBA Kathy Dyer, Ph.D., CCC -SLP, BCBA Anntonette Falco, M.Ed. Lori Frost, MS, CCC -SLP Cheryl Smith Gabig, Ph.D., CCC-SLP Cheryl Gunter, Ph.D., CCC -SLP James Halle, Ph.D. Giri Hegde, Ph.D., CCC-SLP Anne Holmes, Ph.D., CCC-SLP, BCBA Laura Hutt, M.S., SLP -CCC, BCBA James Luiselli, Ph.D. Hedda Meadon, Ph.D. Pat Mirenda, Ph.D., BCBA Pete Peterson, Ph.D. Anna I. 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Cordially, Joe Cautilli and BAO Journals SLP- ABA Volume 5, Issue No. 2 Guest Editors’ Comments M. N. Hegde & Raymond Weitzman We are pleased to offer this special issue of the Journal of Speech-Language Pathology and Applied Behavior Analysis on bridging the gap between the conceptual foundations of speech and language and the treatment procedures used in speech-language pathology (SLP). Our aim in putting this special issue together was to provide the practitioner with a behavioral analytic view of speech and language that is conceptually more consistent with the behavioral treatment widely used in remediating communication disorders in children and adults. Currently, most speechlanguage pathologists (SLPs) who routinely use the behavioral treatment methods accept the linguistic and cognitive theories in understanding language and language development. Linguistic and cognitive theorists, being mentalistic as well as nativistic, seem unable to derive their own useful treatment procedures from their theories. Treatment of communication disorders, by nature, is experimental, and experimental approaches are based on the philosophy and methods of natural science. The behavioral view of language and language development is a natural science account, as opposed to a cognitive, mentalistic, and nativistic approach. It is precisely for this reason that the behavioral approach has generated experimentally verified treatment procedures. Therefore, adopting a natural science account of verbal behavior—a preferred substitute for language—would be more consistent with experimentally based treatment procedures. Conceptual and treatment consistency is not the only advantage of adopting the verbal behavior view of language. It helps the SLPs avoid spurious, speculative, and untestable theories of language and language acquisition. The verbal behavior view eliminates the contradiction of holding a nativistic view of language while trying to modify speech-language behaviors through environmental changes. The behavioral view will help SLPs target functional (cause-effect) language units in assessment and treatment, instead of unstable or unreliable linguistic categories that are unrelated to potential independent variables. Many other advantages are likely to follow with an approach that integrates the basic analysis of language with experimental treatment procedures. This issue consists of six papers that offer a glimpse of various aspects of Skinner’s Verbal Behavior. While the first four papers offer perspectives on the behavioral analysis of language and language development, the last two illustrate the applied aspects of that analysis. Hegde’s paper gives a historical background to the publication of Skinner’s Verbal Behavior and the linguistic criticisms that followed. The paper then goes on to summarize the various functional units of verbal behavior, an understanding of which is essential to appreciating Skinner’s analysis. Dr. Hegde points out the clinical implications of functional units as opposed to linguistic structural units for the work of SLPs. The next paper by McLaughlin offers a behavioral analysis of child language development. Dr. McLaughlin points out that the behavioral view is in fact better able to account for the documented facts of language development in children. Although there has been much research to show that verbal interactions between children and their caregivers are the basis of language learning, the distorted view that only cognitive-nativistic view of language development is valid persists in many textbooks. Dr. McLaughlin counters the generally accepted but unjustified criticism that the behavioral view cannot account for language development in children. Weitzman’s paper, next in the series, addresses what linguists consider a difficult issue for behavioral analysts. The issue often raised relates to the poverty of the stimulus or the alleged 88 SLP- ABA Volume 5, Issue No. 2 inadequacy of language “input” that makes it difficult to conceive how children can learn language without internal mental mechanisms. Although stimuli are only a part of the total contingency involved in learning language (or any other skill), the criticism has been often repeated. Dr. Weitzman argues that the poverty of stimulus hypothesis is unwarranted. He points out that there is plenty of justification to hold that language repertoires in children may be acquired through operant contingencies of stimuli, responses, and reinforcement. Perception, another presumably difficult issue for behavioral scientists, receives a competent behavioral analysis in Schlinger’s paper. Historically, it is a problem of how mind or the brain understands and evaluates sensory information that it receives. The idea that perception is behavior (or action) is radically different from the traditional psychological view that it is some form of passive taking-in of the external world. The traditional definition has been an important basis of infant speech perception research. Although operant conditioning has been the main method of studying whether infants could differentially respond to different speech stimuli, the researchers have resorted to mentalistic and cognitive theories to inconsistently explain their own data. Schlinger makes a compelling argument that it is much more parsimonious to consider perception as behavior and suggests that SLPs may better integrate such a concept of perception with speech and language learning as well as their use of applied behavioral methods in treating disorders of communication. In their paper, Esch and associates addresses the neglected issue of behavioral assessment of communication disorders. Most assessment procedures, whether based on standardized tests or naturalistic language samples, are based on the linguistic analysis of speech and language. Dr. Esch and colleagues point out a great need to develop assessment procedures that target functional verbal behavior units instead of structural categories. Pointing out the limitations of a purely structural assessment, Esch et al. urge SLPs to make a contextual analysis of speech and language skills. Such an analysis will take into consideration the cause-effect relations of verbal behavior units. They argue that a cause-effect based assessment will more easily lead to valid treatment targets. The final paper in this issue by Pistolijev and associates offers an excellent illustration of a new approach to te aching verbal behaviors. Their paper describes how, with the help of the Speaker Immersion Procedure, it is possible to establish speaker repertoire in children with language disorders. Dr. Pistolijev and colleagues demonstrate in their study that with the help of behavioral procedures, it is possible to generate speaker repertoire in noninstructional settings. They further illustrate how Skinner’s functional units may be effective treatment targets for children with language disorders. We hope that the papers included in this special issue will prompt SLPs to gain a better appreciation of Skinner’s Verbal Behavior. We also hope that the SLPs will consider integrating the behavioral analytic view with their assessment and treatment approaches. We thank the Editors of JSLP-ABA for giving us an opportunity to put together this special issue. We are especially grateful to Dr. Mareile Koenig for her competent and friendly support from the beginning to the end. M. N. Hegde Raymond Weitzman Guest Editors 89 SLP- ABA Volume 5, Issue No. 2 Language and Grammar: A Behavioral Analysis M.N. Hegde Abstract While speech-language pathologists (SLPs) accept the behavioral methods of treatment in their professional work, they tend to entertain an inadequate or dismissive view of the behavioral analysis of language and grammar. This may be because SLP’ academic study of language consists mostly of linguistic theories that typically misrepresent Skinner’s (1957) analysis of verbal behavior. An appreciation of Skinner’s analysis would be consistent with the clinicians’ use of applied behavioral techniques in treating speech and language disorders. Therefore, this paper reviews Skinner’s functional units of verbal behavior and his analysis of grammar in terms of autoclitics as secondary verbal operants. Skinner’s analysis is comprehensive, innovative, clinical researchsupported, and relevant to SLPs. Keywords: Verbal behavior, primary and secondary verbal operants, mands, tacts, intraverbals, echoics, textuals, audience, autoclitics, response classes _____________________________________________________________________ Introduction Speech-language pathologists’ (SLPs’) academic study of language is heavily influenced by linguistic and cognitive viewpoints. A majority of textbooks and writings familiar to SLPs explore in greater detail the linguistic and structural view of language and offer only a limited summary of the behavioral view whose concepts and implications are not carried throughout the text. Most SLPs are well versed in the phonologic, morphologic, syntactic, and pragmatic structures of language but are not equally well versed in the functional units that are basic to Skinner’s (1957) analysis. Nonetheless, SLP’s treatment methods are mostly behavioral (Hegde, 1998, 2008a). Inevitably, this has led to a conceptually inconsistent model of language and treatment of language disorders. Chomsky’s (1959) critical review of Skinner’s (1957) book—Verbal Behavior—is better known than the book itself. Most students and clinicians seem to be unaware of the invalidity of Chomsky’s criticism or the competent responses given to his negative review (e.g., Anderson, 1991; MacCorquodale, 1969, 1970; McLeish & Martin, 1975; Palmer, 2006; Richelle, 1976). Rejoinders to his review have pointed out that Chomsky poorly understood Skinner’s Verbal Behavior, behavioral methodology, and behaviorism. Chomsky’s misunderstanding of Skinner’s book and concepts was so severe that it “would prompt most examination graders to read no further” (Richelle, 1976, p. 209). Chomsky frequently attributed views of other psychologists to Skinner who had unequivocally repudiated them. In a questionable case of scholarship, Chomsky repeatedly misquoted Skinner (Adelman, 2007). More than four decades after he wrote the review, Chomsky was still a critic of Skinner, and with the same distorted understanding of Skinner’s work (Virues-Ortega, 2006). A commonly held assumption among most linguists, and SLPs who follow them, is that Skinner’s Verbal Behavior has faded into history. The fact, however, is that research on verbal behavior and treatment of verbal behavior disorders based on Skinnerian analysis are flourishing. Among several others in the Unites States, the journals of The Analysis of Verbal Behavior, The Behavior Analyst, Journal of Applied Behavior Analysis, Behavior Modification, and several international journals on behavior analysis regularly publish many articles on the Skinnerian verbal behavior analysis and treatment. This journal, Journal of Speech-Language Pathology and Applied Behavior Analysis is devoted to bridging the gap between the two disciplines. As Schlinger (2008a) has ably demonstrated, Skinner’s Verbal Behavior is alive and well. An interesting observation Schlinger makes is that although both Verbal Behavior and Chomsky’s (1957) Syntactic Structures had their 50th anniversary in 2007, Skinner’s book on Amazon.com, has been selling better than Chomsky’s. The verbal behavior approach to treating children 90 SLP- ABA Volume 5, Issue No. 2 with autism is now recognized internationally as the most evidence-based approach. Teaching almost all forms of communication disorders is essentially behavioral (Hegde, 1998, 2006, 2007; Hegde & Maul, 2006; Pena-Brooks & Hegde, 2007), whether some SLPs acknowledge it or not. In fact, if any tide has turned against something, it is the tide against Chomsky’s generative linguistics. While Skinner’s experimental and applied behavior analysis is thriving worldwide, Chomsky’s generative grammar notion has disappeared from linguistics (Harris, 1993; Leigland, 2007). Chomsky’s own multiple revisions and qualifications of his 1957 theory have moved away from a cognitive, generative, rule -based theory of language (Schoneberger, 2000). Within just a few years of Chomsky’s Syntactic Structures was published, there was the generative semantic “rebellion” that denied the supremacy of grammar in language. (Linguists often describe newer approaches as revolution, war, rebellion.) Soon came the “pragmatic revolution” which asserted in the 1970s that language should be understood as actions performed in social contexts—mostly an arm-chair philosophical view which was still structural in its orientation. More than 30 years before the “pragmatic revolution,” Skinner had advocated the social nature of verbal behavior with better conceptual and experimental bases than the speculative pragmatic approach has ever had (see Skinner, 1957, Preface, for a historical account of his analysis). SLPs have found that when they need to intervene (i.e., offer treatment), they need to turn toward Skinner’s experimental and applied behavior analysis; linguistics of any era could offer little or no help. Contrary to the typical portrayal of Skinner’s analysis of language as “simplistic,” it is sophisticated, complex, and comprehensive. His analysis of verbal behavior, as he preferred to call it, includes an innovative analysis of grammar, word order, and meaning (Hegde, 2008b) which is unfamiliar to most SLPs. There are other methodological behavioral approaches to language (Osgood, 1963; Mowrer, 1952; Staats, 1968) that are sometimes confused with Skinner’s vastly different radical behavioral approach that offers a natural science view of language, with an ensuing applied technology that SLPs have readily accepted. At least three unique features of Skinner’s analysis of verbal behavior are especially relevant to an applied science of speech-language pathology. First, Skinner’s analysis accepts the constraints of the methods of natural science. Dependent variables are analyzed in relation to their publicly observable, measurable, and experimentally manipulable independent variables. Skinner’s analysis is functional in the sense that it seeks to identify variables that cause verbal behaviors. Explanations of events are kept at the level of observation and experimental analysis, and therefore, do not involve inferred mental, cognitive, or pseudobiological (innate) entities. Second, Skinner’s analysis treats language as a form of behavior, and not as a formal system that exists in the minds or brains of speakers, independent of their actions. Thirty years after the publication of his Verbal Behavior, Skinner (1987, p. 11) restated that his book “is not about language. A language is a verbal environment, which shapes and maintains verbal behavior.” He went on to say that “Those who want to analyze language as the expression of ideas, the transmission of information, or the communication of meaning naturally employ different concepts.” (1987, p. 11). He then urged the scientists to judge which one—a scientific causal analysis or a mental structural analysis—works better. When a causal approach is preferred, analysis of structural properties of mechanically generated sentences (e.g., they are eating apples, or colorless green ideas sleep furiously) are not productive because they do not represent empirical data. Such productions will be of interest to scientists only when they are empirically recorded utterances of speakers, under given conditions of stimulation, meeting specific social consequences. Third, Skinner’s analysis does not include special explanatory laws. He wrote Verbal Behavior to show that “speech is within the domain of behaviors which can be accounted for by existing functional laws, based on the assumption that it is orderly, lawful, and determined, and that it has no unique emergent properties that require either a separate causal system, an augmented general system, or recourse to mental way-stations” (MacCorquodale, 1969, p. 832). Consistent with his analysis of behaviors in general, Skinner has analyzed verbal behaviors in terms of a contingency relationship 91 SLP- ABA Volume 5, Issue No. 2 between (1) current states of motivation, (2) currently controlling environmental conditions, (3) past history of reinforcement, and (4) the genetic constitution of the individual (Skinner, 1957). Operant analysis, therefore, is not restricted to “stimuli and responses” and does not ignore the genetic factors. Verbal Behavior: Definition Verbal behavior (VB) is a class of behavior that is “reinforced through the mediation of other persons” (Skinner, 1957, p.2). Verbal behavior is social behavior, because, unlike nonverbal behavior, it cannot be conditioned or maintained by nonsocial entities. Nonverbal behavior in this context does not refer to nonvocal verbal behavior (as in alternative forms of communication). It refers to behaviors that are, in traditional terms, noncommunicative (e.g., walking or watering a house plant). Contrary to nonverbal behaviors, verbal behavior may be conditioned only by the actions of other people. The essence of Skinner’s definition is that it is only people who get affected by it in such a way as to get conditioned to reinforce VBs. In other words, both the VBs, and their consequences (listener responses), are conditioned. Also, unlike nonverbal behaviors, VBs are devoid of direct and mechanical reinforcement contingencies (Skinner, 1957; MacCorquodale, 1969). As E. Vargas (1988) distinguished them, VBs are verbally governed (mediated), whereas nonverbal behaviors are (environmental) eventgoverned. Consider the example that contrasts a nonverbal response with a verbal response: A thirsty woman may walk up to the refrigerator and get a drink. The nonverbal response of walking will directly and mechanically get reinforced when she gets her drink—an environmental event. No other person need be present to reinforce it. But instead, if her response is verbal (e.g., “May I have a glass of water?”), it needs social mediation to get reinforced. Someone (mediator) has to reinforce it by complying with her request. The need for a mediator to select and strengthen VBs adds an additional element to the familiar three-term contingency involving stimuli, responses, and consequences that explains nonverbal behavior. VB, therefore, is explained on the basis of a four-term contingency that involves (1) stimuli, (2) verbal responses, (3) listener responses, and (4) the reinforcing effects of listener responses (J. Vargas, 2009). It should be noted however, that in all other respects, VB is essentially like nonverbal behavior. For instance, verbal and nonverbal behaviors both have their respective discriminative stimuli, and are similarly selected and strengthened by their consequences, and may be extinguished by withholding reinforcement (E. Vargas, 1988). Also to be noted is that the uniqueness of VB does not require special explanatory laws; Skinnerian laws of behavior are sufficient to account for it. Verbal Behavior: Units of Analysis An analysis of verbal behavior should first determine the units of analysis. Linguists analyze language with such structural units as phonemes, morphemes, words, and sentences that may be adequate for a formal analysis of language. Skinner asserted that linguistic structures tell us nothing about their causes—but the natural science account of any phenomenon is a causal analysis. Apparently, structuralists presume that independent variables can be sliced according to the structural properties of responses. That is, phonemes, words, sentences, and so forth necessarily have separate causal variables— a presumption without empirical support. Skinner’s analysis shows that the same cause may lead to the production of a word, a phrase, or a sentence depending on the current stimulus condition and past reinforcement history. For instance, one might just say, “yuck” or “I think it is disgusting”—variable structural units under similar stimulus conditions and similar effects on listeners. To the contrary, the same verbal response may be controlled by different independent variables in different situations. For instance, a boy might say “ball” because he saw a ball, or echoed someone else, or read the printed word ball. —different causes for structurally the same response (“ball”). That structures (forms) and causes do not covary is unaccounted for in the linguistic analysis. A word is always a word, regardless of why it was produced. A sentence is different 92 SLP- ABA Volume 5, Issue No. 2 from a word, though it may have the same cause as a word on a given occasion. Skinner’s analysis of verbal behaviors based on their independent variables avoids this problem inherent to structural analysis. Technically, the response unit in the behavioral analysis is called a verbal operant which is “. . . a disposition (tendency, likelihood) to respond in a certain way to a certain state of affairs because of a past history of reinforcement” (Winokur, 1976, p. 21). A given verbal response is concrete, and is an exemplar of a class of responses. In contrast, a verbal operant is abstract because it means both a controlling relation and a class of verbal responses with similar causes and conditioning history. Skinner classified VBs on the basis of motivational variables, discriminative stimulus control, and other VBs (that cause additional VBs). The following sections of this paper summarize distinct verbal operants, beginning with mands. Motivational Control: The Mand A mand is a verbal operant whose cause is a motivational variable. States of deprivation or aversive stimulation cause mands to be emitted by a speaker. Skinner defined the mand as “a verbal operant in which the response is reinforced by a characteristic consequence and is therefore under the functional control of deprivation or aversive stimulation” (1957, p. 35-36). Under a state of deprivation, positive reinforcers (consequences individuals work to obtain) will be effective. Under conditions of aversive stimulation, negative reinforcers (consequences that remove such stimulation) will be effective. In either case, a mand of any form, including speaking, writing, signing (e.g., American Sign Language), pointing, finger spelling, and sending Morse codes may be emitted (Michael, 1982). Responses such as A glass of water, please or May I have a hamburger are controlled by states of deprivation and are reinforced positively. States of deprivation are motivational, and deprivation simply means that a person has not had access to something specified for some measured duration. Responses such as Quit that or Get out are controlled by their respective aversive stimulus and are reinforced negatively when the listener complies. In all cases, a mand specifies its own reinforcer; for instance, the mand, Will you please be quiet specifies what will (negatively) reinforce that mand: cessation of chatter. When mands are produced, an appropriately conditioned listener will act in ways that are reinforcing to the speaker. Produced mostly for the benefit of speakers, and propelled by states of motivation, particular forms of mands do not strictly covary with discriminative stimuli present in the environment. For instance, a speaker’s mand, “May I have an apple pie?” is more likely in places where pies are available . Nonetheless, one might also say, “I want to eat a piece of pie” when none is in sight; it may function as a mand if another person who hears it proceeds to bake a pie. Occasionally, when deprivation is very strong, mands may be completely free from external stimulus control, as in the “isolated desert-dwelling hermit’s cry, ‘water’” (Winokur, 1976, p. 30). In general, requests, commands, prayers, advice, questions, warnings, permissions, offers, and the like are mands. Note that multiple linguistic categories are reduced to just one (mand). Whether an utterance is a mand or not cannot be determined by its structural properties. The utterance of the word “Fire!,” for example is a mand when addressed to a firing squad, a textual when read aloud from print, a tact when it is evoked by the sight of fire, and an echoic when a child in therapy imitates that modeled word. Similarly, the sentence I see fire may be a tact, a textual, or an echoic, each with its own cause. Skinner (1957) also described a variety of generalized mands, which seem irrational but are nevertheless lawful. Extended mands occur when people mand small babies, dolls, untrained animals, and machines (e.g., a driver’s mand at a stop light, “Common, green light!”) that do not reinforce the speaker. They are maintained because of a past history of reinforcement for similar responses emitted under similar conditions. 93 SLP- ABA Volume 5, Issue No. 2 Clinical Implications SLPs should be especially interested in teaching mands to children and adults with language disorders. Traditionally, SLPs have shown greater interest in teaching tacts (see the next section)—the perennial naming of objects and colors rather than mands. Mands, however, are an important class of verbal operants that clinicians should target in both early and later stages of language intervention with children as well as adults. Even individuals with aphasia, traumatic brain injury, or dementia would be better functional communicators if they could mand. In fact, what is promoted as functional communication in speech-language pathology is, for the most part, mands. For the purpose of clarification, it should be noted here that function in the speech-language pathology literature does not refer to causes, as it does in natural science and behavioral analysis. Instead it vaguely refers to the “use of language.” It is generally and correctly asserted that individuals with significant communication problems but who learn to “express their basic needs,” “ask for information,” “request for clarification”— all mands—are better functional communicators than are those who name or describe objects. A woman whose husband is aphasic does not especially care if he can describe or name (tact) water; she will be content if he can mand it when thirsty. Michael (1988) suggests that about half of what adults say in the course of a daily interaction with others may consist of mands. Some SLPs may assume that children who are taught the labels (tacts) for objects, will mand the objects they want. Contrary to this assumption, clinical VB training, or what is beginning to be called the verbal behavior approach (Barbera, 2007; Miguel, 2009), has made it clear that children who learn tacts may not automatically mand; they need mand training as well (Hall & Sundberg, 1988; Michael, 1988). Children who cannot mand often resort to such undesirable behaviors as tempter tantrums, whining, grabbing, and aggressive nonvocal acts because they cannot request what they want (Carr, et al., 1994.) Nonverbal or minimally verbal children are especially prone to unacceptable problem behaviors to socially acceptable manding. Teaching mands first to such children may reduce many undesirable behaviors because the mands will give them access to the same reinforcers that their undesirable behaviors successfully sought (Carr, et al., 1994; Reichle & Wacker, 1993). Other classes of VBs may then be more efficiently taught to children whose undesirable vocal or nonvocal mandin g behaviors have been replaced by desirable vocal mands. In more recent research on teaching VB to children and adults who have not learned a verbal repertoire, the concepts of deprivation and aversive stimulation have been refined further to account for some varied conditions under which mands tend to be produced. Generally, and as noted, mands may be produced under states of deprivation or aversive stimulation. For instance, a person who has not had access to water for several hours is likely to request it when the conditions that support a mand exist. However, a person may also mand for a drink when he or she has just ingested salt—a condition that bar owners tend to exploit by offering salty pretzels to its patrons who, after eating them, order (mand) more drinks (J. Vargas, 2009). Eating pretzels creates a state of fluid deprivation, but is not, in itself, a state of deprivation. SLPs offering language treatment to infants and toddlers often schedule language treatment sessions just before their young clients have had breakfast or lunch to increase the probability that the food used as a reinforcer during the sessions might be more effective than when the children arrived at the clinic after a full meal. Similarly, a teacher who plans to increase question-asking behaviors (mands) in her students may increase the difficulty of an academic task. This aversive task difficulty may increase the probability that the students ask for help; the teacher may then use prompts, models, and other procedures to teach mands (request for teacher’s help). Such necessary steps taken to increase the motivation for mands (or other nonverbal behaviors) are known as establishing operations (EOs), a term Keller and Schoenfeld had used in 1950, but expanded and refined by Michael (1988, 2000). EOs also are known as motivating operations (MOs) (J. Vargas, 2009). Under natural settings involving speakers with good mand repertoire (such as the adult in the bar), EOs increase the probability that a mand will be produced. Under clinical conditions involving speakers with limited mand repertoire, establishing operations make it somewhat easier to teach mands. In essence, EOs have two kinds of effects that 94 SLP- ABA Volume 5, Issue No. 2 clinicians can exploit. First, they alter the reinforcing effects of some object, event, or activity; this is the reinforcer-establishing effect. Second, EOs change the current frequency of behaviors that were previously reinforced by that object, event, or activity; this is the evocative effect. The two effects of EOs are independent and concurrent (Michael, 2000). In light of these refinements of the motivational variable, Michael defines the mand as “a type of verbal operant in which a particular response form is reinforced by a characteristic consequence and is therefore under the functional control of the establishing operation relevant to that consequence” (1988, p. 7; emphasis added). EOs may be unconditioned (UEO) or conditioned (CEO). Biological propensities underlie UEOs whereas past learning underlie CEOs (Hall & Sundberg, 1988; Michael, 1988). Asking mothers to bring infants to early language intervention sessions just before breakfast, and then using breakfast food as reinforcers for vocal responses is an example of UEO. The infant’s sensitivity to food is biologically determined (hence unconditioned or unlearned), although the specific types of food preference is learned. On the other hand, an EO that increases the value of a toy as a reinforcer for a child under mand training is an example of CEO. An preferred toy placed on a high shelf may temporarily increase its value as a reinforcer and the probability that the child will mand it. A missing item necessary to complete a task might also create a CEO to teach mands, as Hall and Sundberg (1987) demonstrated. While teaching a student who is deaf to make soup, the authors omitted the needed hot water to create a CEO that helped teach the mand, “hot water.” It may be noted that if the water manded is immediately consumed, any EO the clinician will have manipulated would be unconditioned; if the water manded is not consumed, but is used for some activity (such as washing hands or cooking a meal), then any EO in effect is conditioned. The classic conditioning literature not only had recognized the effect of deprivation (currently, part of EOs), but also that of satiation. While deprivation increases the value of a reinforcer and the response rate associated with it, satiation decreases both. A person who has just eaten is unlikely to mand food. This effect of deprivation, too, is crucial for the clinician who plans to teach mands for food and drink. As a child receives food following successive mands, the reinforcing value of food is likely to decline, and so is the response rate. The term abolishing operations has been used to refer to those aspects of EOs that reduce (a) the reinforcing value of some object or activity and (b) the response frequency associated with that object or activity (McGill, 1999; Michael, 2000). There exists an extensive literature on EOs in behavioral literature (see McGill, 1999 and Smith & Iwata, 1997 for reviews) and mand training (see Sautter & LeBlanc, 2006 for a review of treatment research). In most of the studies, EOs were manipulated to decrease undesirable behaviors (e.g., selfinjurious behaviors). However, EOs are important in mand training because the clinician need not wait for opportunities to arise for the child to produce it. Instead, the clinician can create conditions (EOs) that encourage manding more frequently and thereby make the mand training more efficient (e.g., Hall & Sundberg, 1988). It is also evident from VB treatment research that what SLPs call language initiation, an important skill targeted in language therapy with children, is, for the most part, manding. Teaching mands to children with impaired VB (language disorders) is an effective way of teaching verbal initiation (Taylor, et al., 2005). Consistent with Skinner’s suggestion (1957), VB treatment research also has shown that mand training facilitates the training of other verbal operants (Sautter & LeBlanc, 2006). Discriminative Stimulus Control: The Tact Discriminative stimuli are aspects of the environment that control certain verbal responses. A discriminative stimulus sets an occasion for a response that has characteristically received reinforcement in the past. Although some people mand much, tacts that are controlled by discriminative stimuli are a significant portion of most people’s everyday speech. A tact is a verbal operant evoked by objects or events in the environment and reinforced by a verbal community in the presence of those objects and events. Discriminative stimuli that control tacts are “nothing less than the whole of the physical environment—the world of things and events which a speaker is said to “talk about’” (Skinner, 1957, p. 95 SLP- ABA Volume 5, Issue No. 2 81). Motivational variables, critical for mands, are unimportant for tacts, which may be described as “objective” or “disinterested.” Tacts say less about speakers' internal states than they do about their physical world; mands do the opposite. At the simplest level, naming could be a tact. At the next level of complexity, descriptive statements could be tacts. Normally, listeners reinforce tacts based on the relation or correspondence between the tact and its antecedent. For instance a tact such as grass is reinforced if the controlling antecedent is indeed grass; but the tact grass is green is reinforced on the basis of a correspondence between the object grass and its conventional color. When the speaker is a child learning VB, however, tacts whose forms do not show strict correspondence with their adult forms, and hence lack the conventional correspondence with the antecedents as well, may still be reinforced. When the child says “da,” for example, the mother may say, “Yes, that is a dog!” and thus reinforce the child’s tact, even though that tact does not correspond either to its discriminative stimulus (in the adult sense) or to its adult topographic feature. Gradually, the mother demands greater correspondence, and an appropriate repertoire of tacts is established. Tacts, though generally controlled by discriminative aspects of the physical environment, do not have a point-to-point correspondence with their antecedents. Echoics and textuals (see the subsequent sections) have such a correspondence. Tacts evoked by environmental stimuli soon become more complex due to the recombinative arrangements with other verbal operants; intraverbals, described later, help generate continuous speech in the absence of a parade of physical stimuli. While mands are likely to be reinforced by unconditioned reinforcers, generalized conditioned reinforcers always reinforce tacts. In most situations, these reinforcers are verbal responses of listeners: right, correct, good, I agree, I think so, very interesting, and so forth. These and other reinforcers are often interchangeable, and the speakers will get reinforced as long as their verbal responses bear a conventional correspondence with their antecedents. Lack of correspondence can lead to conditioned punishers: No, that is not green; I don’t agree, I see it differently, and so forth. Like any other response, tacts, once conditioned, will generalize to similar stimulus situations. Various kinds of generalization vastly expand the tact repertoire. A generic or simple generalization of a tact is observed when a child or an adult produces an established tact (“ball” or “pen”) to a new stimulus (e.g., a new ball or a new pen). More complex forms of generalized tacts are involved in what are considered metaphor (including simile) and metonymy. Metaphorical generalizations (that create what are generally called metaphors), philosophically and linguistically thought to be a cognitive and creative achievement of a high order, also are a special kind of tacts under more refined discriminative stimulus control. Skinner’s (1957) example, Juliet is the sun (metaphor) or Juliet is like the sun (simile), shows that the variables that controlled Romeo the speaker are sun and Juliet who shared some common stimulus property that affected him. Creative as they may be, metaphors and similes arise out of discriminated and shared properties of stimuli that control them, not out of some presumed cognitive processes or intellectual achievements. Metonymical generalization of tacts accounts for verbal operants that seem to have no controlling stimuli (Skinner, 1957; Winokur, 1976). Metonymy is the act of naming something with another word that is associated with it. In behavior analysis, metonymical expressions seem to lack a relevant stimulus, as shown in the example that follows. These verbal operants pose a particularly difficult problem to the linguists and cognitive theorists. How do speakers tact objects that are missing, which they do all the time? If the object is missing, and the response is “about” that object, what is the discriminative stimulus for that response? In linguistic -semantic analysis, responses of this kind are classified as nonexistence. In cognitive analyses, the speaker emitting such a response is said to “recognize the absence of an object that was once present.” Unfortunately, what is recognition, and how the absence of something is recognized, pose additional explanatory challenges. A missing object cannot be a stimulus for a response, just as a missing cause does not produce an effect. For example, when a child, while looking at the toy shelf, 96 SLP- ABA Volume 5, Issue No. 2 says, “No truck,” we cannot conclude that the missing truck controlled that response. Many other objects, not just trucks, were also missing, but the child did not tact them. The response “No truck” is actually controlled by the currently present stimuli (e.g., toys that are present, along with perhaps the empty space on the shelf) that coexisted with the missing truck. The toy truck has been a part of those stimuli in the presence of which the response truck has been reinforced in the past. Clusters of stimuli have common elements, and a response conditioned to one of them is also conditioned to all or some of the individual elements in clusters. The speaker who again confronts one or some of those elements is likely to emit the response in question. This is called metonymical extension (generalization) of responses. Metonymical generalizations also account for more complex tacts than just naming a missing object (Skinner, 1957; Winokur, 1976). A journalist’s report that the “White house asserts that the recession is over,” is indeed what the President or a spokesperson has said. Specific speakers and the White house are commonly associated with each other; therefore, they share a controlling relation to the tacts. Certain processes governing tacts lead to abstraction. A controlling stimulus is typically composed of multiple and discriminable (isolatable) properties such as shape, size, color, texture, configuration, use, function, and so forth. A verbal response under the control of an isolated discriminable property of a stimulus is an abstract response. Skinner wrote that “abstraction is a peculiarly verbal process because a nonverbal environment cannot provide the necessary restricted contingency” (1957, p. 109). In other words, nonverbal environment cannot teach abstractions; only a verbal community can. For instance, in teaching the child an abstraction of red to redness as such, the verbal community (or a clinician) will have to reinforce the tact “red” made in relation to objects that are red, but vary in shape, size, texture, and to a point, hue. However, because these irrelevant properties (e.g., shape or size) also gain some control over the verbal tact “red,” the teachers must reinforce differentially. The response red is reinforced always and consistent with redness, but regardless of other properties of red stimuli. In this kind of teaching, irrelevant stimulus properties do not covary with reinforcement whereas redness does, and thus comes to control the tact “red.” As a result, a response is created that tacts an abstract property of a stimulus that varies in other properties. Skinner’s analysis of tacts is extensive, and includes provocative discussions on how people come to tact private stimuli—stimuli that arise within the speaker’s body, and more importantly, how the verbal community manages to arrange contingencies of reinforcement for them. In addition, discussions on problems of reference and meaning (Hegde, 2008b), and a variety of literary behaviors also are included. Clinical Implications Generally, SLPs do a good job of teaching tacts, although the clinicians have tended to conceptualized what they teach in linguistic terms (naming and describing objects and events). Although tact teaching is important, there may sometimes be an overreliance on teaching simple tacts at the expense of other verbal operants, especially mands, intraverbals, and autoclitic (often grammatic) relations. Simple tacts are typically the responses given to the mand, “What is this?” Except at such simplest level of object naming, tact training will include different types of verbal operants. Individual words expanded into topographically more complex combination of verbal operants (phrases and sentences) include mands, intraverbals, and autoclitics (certain morphologic and syntactic aspects). As we shall see in a later section, most everyday speech is a combination of different verbal operants. For instance, after teaching a child to tact “ball” to certain round objects, the clinician may teach the child to produce The ball is red, which consists of two tacts (ball and red) with two autoclitics (the and is). Similarly, the child mat learn to say, give me that red ball, which consists of a mand, two tacts (red and ball) and an autoclitic (that). Therefore, pure tact training should soon give rise to a higher level of training in which different verbal operants are combined into what are commonly called sentences and that Skinner (1957) considered as larger segments of VB resulting from autoclitic activity. 97 SLP- ABA Volume 5, Issue No. 2 After the mand, the tact is the second most frequently targeted verbal operant in VB treatment research (Sautter & LeBlanc, 2006). Possibly, if child language treatment research published in speechlanguage pathology and other related discipline journals is included, the tact may be the most frequently taught verbal operant. In most VB treatment research, tacts were taught in combination with other verbal operants. Several studies also have analyzed the functional independence of tacts from other verbal operants (mands, intraverbals, and echoics). The findings have generally supported Skinner’s assertion that verbal operants have different causes and need separate training, although in a few studies generalization across functional units have been noted (Sautter & LeBlanc, 2006). Verbal Behaviors Caused by Other Verbal Behaviors Skinner wrote that “behavior generally stimulates the behaver” (1957, p. 138), and VB can stimulate other VBs. Intraverbals, echoics, and textuals are the three kinds of VBs whose controlling variables are VBs themselves. Intraverbals VBs whose controlling variables are prior verbal responses are called intraverbals. A defining characteristic of intraverbals is that there is not point-to-point correspondence between intraverbal responses and their stimuli. Such a correspondence is more evident in tacts, and most in echoics (imitative responses that duplicate their own stimuli) and textuals (naming printed stimuli—reading). Some intraverbals may be generated by another person’s verbal responses. A speaker may say “four” when someone utters “two plus two is . . .” However, the most important classes of intraverbals are those that are controlled by the speaker’s own prior VBs. Speech, once initiated by some variables, is capable of evoking more speech in the same person. Much of everyday conversation is intraverbal, as are serious discussions. One speaker’s production of “Why?” often evokes the production of an intraverbal “Because . . .” in another speaker. Similarly, “Fine, thank you” may be an intraverbal response to “How are you?” (Skinner, 1957). The instructor who asks the class, “What is a discriminative stimulus?” hopes that the question will generate an intraverbal response of “A discriminative stimulus is . . .” The instructor also hopes that what follows is an accurate (reinforceable) and complete intraverbal. Most of lower or higher education is designed to generate intraverbal responses that the ordinary verbal community may not establish. As these examples show, an utterance is not only a response to some other variable, but it also is a stimulus to subsequent utterances. People often “go on speaking” not because of a “train of ideas” rushing inside their heads, but because of the stimulus function of their own verbal responses. Most likely, intraverbal control is a significant contributor to speech fluency (Hegde, 1982). Intraverbals can be either chains or clusters (Winokur, 1976). Intraverbal chains have a fixed order upon which the delivery of reinforcement is contingent. In reciting a poem, one part controls the other in a sequential manner. The child acquires the alphabet as a chain in which one letter supplies the necessary stimulus for the next. When the recitation of the alphabet gets interrupted, the child usually goes back to recreate the stimuli for subsequent responses. Counting is chaining, as are formulas, syllogisms, and symbolic logic. History is taught and learned as intraverbals. Skinner cautions, however, that “any one link in a chain of responses is not under the exclusive control of the preceding link” (1957, p. 72), because repeating just the last emitted letter of an interrupted recitation of the alphabet may not reinstate the chain. Intraverbal clusters are groups of verbal operants that can evoke each other with no specific order or grammatical connection. Moreover, clusters are bidirectional, while chains are unidirectional. Word association test responses are clusters. The verbal response “ring,” for example, can serve as a discriminative stimulus for clusters, such as: (1) “gold,” “diamond,” “hand,” “finger,” “engagement;” (2) “noise,” “clang,” “bell,” “door;” (3) “worm,” and perhaps other clusters (Winokur, 1976). However, a 98 SLP- ABA Volume 5, Issue No. 2 member of any one cluster is usually not a member of any other cluster, although all the clusters in question may have the same discriminative stimulus. Intraverbal clusters are of two types, thematic and formal (Winokur, 1976). In thematic clusters there is no acoustic similarity between the verbal response that serves as the discriminative stimulus and the response it evokes. There is such a similarity in formal clusters. In thematic clusters, verbal stimuli and responses evoke each other because they share common “meaning” in the sense that they have entered into similar contingencies of reinforcement. For example, “ring,” “noise,” “clang,” and “bell,” are all about the same thing. In formal clusters, stimuli and responses come together because they sound similar acoustically: the word “hat” may evoke “cat,” “mat,” “pat,” and “chat.” Thus, rhyming as a phonological skill may not suggest some kind of awareness or knowledge, but phonetically controlled formal clusters (intraverbals). Formal clustering is explained on the basis of response induction, a behavioral process in which new responses similar in form to those reinforced earlier are likely to occur. Intraverbal relations have also been described in terms of divergent and convergent control. A cluster that consists of the verbal stimulus “Chair” and several evoked intraverbals (e.g., “table,” “sofa,” “dining,” “reclining,” etc.) illustrates divergent intraverbal control; a single stimulus evokes multiple and varied intraverbal responses. A different cluster that consists of varied verbal stimuli (e.g., “four legs,” “made of wood,” “something to sit on,” etc.) and a single evoked intraverbal “Chair” illustrates the convergent control (Axe, 2008). Because of their general complexity, intraverbals require not a simple discrimination, but a conditional discrimination, in which one verbal stimulus changes the evocative effect of another verbal stimulus, and in combination, they evoke an intraverbal response (Axe, 2008). See the next section for examples and teaching implications of conditional discrimination in intraverbal relations. Clinical Implications SLPs who describe language disorders in terms of lack of continuous speech, limited conversational skills, impaired sentence completion tasks, lack of topic initiation and maintenance, limited production of synonyms and antonyms, limited production of proverbs and common sayings, are indeed describing impaired intraverbal relations. Impairment in intraverbal relations is a higher level VB disorder than deficiencies in producing mands and tacts. To establish the higher level intraverbal skills in the repertoires of children and adults with language disorders, SLPs first need to teach the more basic verbal operants, including echoics, mands, and tacts. For instance, to learn the intraverbal, “In the winter, the big white bears hibernate,” emitted as an answer to the question, “What do the big white bears do in winter?,” the client should have all the tacts of that intraverbal in his or her verbal repertoire; if not, the clinicians will have to first establish them. In the SLP literature, there are few or no studies on teaching explicitly described intraverbal relations to children and adults. Nonetheless, SLPs have taught intraverbals to their clients, though they have not conceptualized them as such. Clinicians often teach words to children with language disorders by (a) presenting a stimulus, (b) asking a question (e.g., “What is this?”), (c) immediately modeling the response (e.g., “Say, ball”) and (d) reinforcing the correct response from the children. Later, they fade the model, and just present the stimulus, ask the question, and reinforce the response. This sequence of procedures is a way of establishing intraverbal relations. Clinicians routinely exploit a premorbidly well established intraverbal relation, even if it is currently weakened, to evoke intraverbal responses in clients with brain injury. For instance, clinicians often prompt in the form of an incomplete sentences (e.g., “You eat with a . . .) to evoke an intraverbal response “fork” from a client with aphasia. Phonetic cues, (e.g., the word starts with a p . . .”) or cues based on the use of an object (e.g., “You write with it”) also are examples of strategies to train or retrain intraverbal relations. Asking children to name individual members (e.g., cats, rats, dogs, etc.) of a class of stimuli (animals) is another method of establishing intraverbals. Responses to such directions as “Name some animals” are intraverbals. Intraverbals are 99 SLP- ABA Volume 5, Issue No. 2 established as well when children learn to respond with synonyms when an antonym is supplied or (and vice versa) or when they learn to give correct definitions when asked to define terms. In VB treatment research, there are several controlled treatment studies on teaching intraverbal relations to clients who lack them. These studies help guide SLPs develop treatment programs to increase explicitly defined intraverbal relations in children and adults who have limited verbal repertoire. Cihon’s (2007) review of studies on training intraverbal repertoire and the specific studies cited in it are helpful to clinicians in designing their own intraverbal treatment programs for children and adults with VB (language) disorders. Cihon describes peer training, conversational speech training, the discrete trials, and several other educational methods (e.g., direct instruction and precision teaching) as effective procedures to establish intraverbal relations. Echoics Much has been written on the role of imitation in language learning. It may be so because echoics (imitated verbal responses) are perhaps the earliest of vocal operants. An echoic is a verbal response whose acoustic pattern resembles that of its own verbal stimulus. In effect, an echoic reproduces its own stimulus. Echoics are reinforced when the responses more or less accurately reproduce the acoustic characteristics of their stimuli and closely follow the stimuli. Repeating what someone said in the recent or remote past is not echoic verbal operant. Echoics are verbal operants preceded by the same or closely resembling verbal stimuli (Skinner, 1957). Because they are reinforced verbal operants, no special faculty or instinct is presumed to be responsible for them. Listening consists mostly of covert echoics. [Incidentally, listening, the other part of VB, is not covered in this paper; but see Schlinger, 2008b for the Skinnerian view that listening is behaving verbally.] At the least, a listener may covertly repeat the important parts of a speaker’s responses. The recipient often covertly and overtly repeats complicated traffic directions. In everyday conversation, speakers tend to echo one another’s words or peculiar phrases. Certain work orders or complicated instructions also may be immediately repeated (echoed). Skinner (1957) also describes self-reinforcing self-echoic behaviors that are often called palilalia if they are excessive, apparently uncontrolled, or pathological in other ways. Even the so-called verbal perseveration seen in individuals with neurological disorders may be described as fully or partly self-echoics. It is important to note, therefore, that echoics are not limited to simple imitations. Echoics in a child’s repertoire gives a distinct advantage to the verbal community that teaches its language. The teaching begins with babbling, but both the infant and the caregivers have some ways to travel before they arrive at helpful echoics. Echoics as early operants are shaped from the baby’s tendency to initially exhibit unconditioned and undiscriminated babbling (i.e., non-operant vocalizations that are neither an echoic nor any other kind of verbal operant). Nonoperant babbling occurs when well fed (and relaxed) babies are lying on their back, and the air movement through the vocal folds causes them to vibrate, resulting in random sounds or noises. Because it is random (not yet selected by reinforcement), it is likely to include sounds that are not specific to the infant’s verbal environment (the family “language”) (McLaughlin, 2006). That the infant’s babbling may include some sounds alien to the infant’s verbal environment is neither surprising nor remarkable. There is no justification to hypothesize that the nonoperant and unselected (unreinforced) babbling is due to some innate mechanism because such babbling is a physiological-aerodynamic phenomenon. The reinforcing effects the caregivers themselves experience from the infant’s nonoperant babbling that establishes an interlocked set of caregiver-infant reactions that help the emergence of other verbal operants. The interlocked chain of reactions include the parent’s echo-babble, infant’s self-echoic babble, caregivers’ reinforcement, infant’s operant babble, and the more refined reinforcement made contingent on sounds of the surrounding (family) environment that eventually help establish mands, tacts, 100 SLP- ABA Volume 5, Issue No. 2 and other verbal operants. It is interesting to note that the initial reinforcement occurs for the caregivers, who, (in everyday language) take delight in the random sounds or syllables their babies produce. That their babies’ vocal sounds and syllables are conditioned reinforcers to the caregivers and (soon) to the babies is central to the development of initial echoics and their transformation into other verbal operants. Baby’s babbled sounds and syllables reinforce the caregivers because who will have had a long verbal learning history; speech (and its individual sounds) have been socially reinforcing to them; lack of speech is socially aversive. The reinforcing effects of their babies’ nonoperant babbling causes two main changes in the caregivers’ behaviors. First, they echo-babble their babies’ babbles. That is, the caregivers repeat what the babies babble. Second, the caregivers produce similar sounds and syllables while they are reinforcing their babies with their caretaker routines: changing, bathing, drying, dressing, feeding, holding them closely, and playing with them. The vocal sounds of the caregivers, by association with such reinforcers, acquire conditioned reinforcement value for the babies. Next, the sounds the babies hear themselves produce are immediately and automatically reinforced, causing an increase in babbling. It is known that babies who are deaf begin to babble but soon stop—possibly because of lack of automatic reinforcement. This reinforcement also may be the reason why babies self-echo; that is, they repeat their own babbled sounds in a stage of language development researchers call reduplicated (e.g., da-da-da) babbling (McLaughlin, 2006). A different type of condit ioning also begins to take place. Parents, hearing the babies’ babbled sounds, syllables, and self-echoics, begin to socially reinforce them (e.g., by smiling, tickling, picking the babies up). There is experimental evidence that such contingent social reinforcers increase babbling in babies. (See Hegde, 1998 for reviews of classic studies and Bloom, Russell, Wassenberg, 1987; Goldstein, King, & West, 2003, Goldstein & Schwade, 2008, Gros-Louis, West, Goldstein, & King, 2006 for more recent studies in which caregiver reinforcement has systematically increased babbling in babies.) One typical objection to this analysis is that parents do not plan to reinforce and that they cannot reinforce consistently (Owens, 2005). A point worth noting is that the caregiver reinforcement need not be planned (McLaughlin, 2006) nor should it be continuous to increase nonechoic, echoic, or self-echoic babbling. There is evidence that caregivers attend to (reinforce) about 50% infant vocalizations (GrosLouis, et al., 2006). It is well known that intermittent (less than 100%) reinforcement increases both the frequency and the strength of behaviors so reinforced (J. Vargas, 2009). Indeed, because of intermittent reinforcement, infant vocalizations resist extinction when reinforcers are not forth coming (Goldstein, Bornstein, Schwade, Baldwin, & Brandstadter, 2007). Nonetheless, in their sources on language development, SLPs are likely to be told, without any review of studies, that “There is very little evidence that the infant’s babbling is shaped gradually by selective reinforcement” (Owens, 2005, p. 77). Nor is there any evidence that the effects of reinforcement are always slow and gradual, even if these could be operationalized. There is now stronger evidence that self-echoic babbling, caregiver echoics, and reinforced babbling serves as a basis for more complex verbal operants, because one theory that discounted that possibility has been discredited. This is Jakobson’s (1968) theory of discontinuity between early vocalizations and later language development. Most researchers now agree that there is a continuity, and thus there is support, for conditioned echoics playing a significant role in VB learning (McLaughlin, 2006; Pena-Brooks & Hegde, 2007). Later on, babies’ responses at the word level are often partial echoics (approximations) as in dada for daddy. Nevertheless, parents tend to reinforce them initially, but gradually, the parents require progressively better approximations, resulting in complete echoics. While partial or complete echoics are being reinforced, other variables, such as persons, objects, and events also are present. Eventually, these variables gain discriminative stimulus control over the response. Michael (1982) suggests a new term, duplic, to extend Skinner’s echoic verbal operant to include sign language, which does not have a vocal stimulus that typically evokes a vocal echoic (or other verbal operants). The new term captures the essence of a verbal operant whose stimulus need not be verbal; when one person—often a teacher—signs, the other person—often a learner—copies the sign (imitating, 101 SLP- ABA Volume 5, Issue No. 2 not “replying”). The term duplic includes not only sign imitations, but also copying texts. The term captures both the auditory and visual stimulus modes, and therefore, may be preferable to the term echoic. Clinical Implications Regardless of the theoretical differences on the importance of echoics in language learning, SLPs routinely establish echoics (typically called imitations) in most of their treatment sessions. Echoics may help establish verbal operants of any topographic feature: words, phrases, and sentences. The verbal stimuli SLPs give to evoke echoics in their clients are called modeling, although within a behavioral framework these models are also mands (e.g., “Say, ball”). In everyday speech, modeling is not the necessary stimulus for echoics. In the typical verbal environment, a speaker need not manipulate a stimulus to call the resulting response an echoic. A speaker who says, “Remember, meeting at 3 p.m. today,” is not necessarily modeling for the listener to echo; but the listener may still overtly or covertly echo it: “meeting at 3 p.m. today.” The initial speaker may still reinforce the listener’s overt echoic (“Yes, that is the time!”) while not having explicitly set the stage for it. Some of the earliest treatment studies on child language and speech disorders conducted in the 1960s and 1970s, reported that the modeling-imitation-reinforcement sequence was effective in establishing echoics that may be shaped either into topographically more complex responses or other classes of verbal operants (see Hegde, 1998 for details). For instance, once such tacts as ball and big are established, the client may be taught such mands as I want big ball or such tacts plus autoclitics as that is a big ball. Verbal operants that are at zero baseline almost always need to be first established as echoics. Shaping should be added to echoics when echoics are not produced on baselines (Hegde, 1998). Echoics have been found to be a useful initial teaching target in treating adult communication disorders, including aphasia, apraxia of speech, and dysarthria. Whenever echoics are established as a starting point in treatment, clinicians fade modeling to bring the client’s verbal responses under the control of more natural stimulus conditions (e.g., motivation in the case of the mand, and discriminative stimuli in the case of the tact). Textuals Skinner defined the textual as a vocal response that “is under the control of a nonauditory verbal stimulus” (1957, p. 66). Most commonly, the printed text is the visual controlling (causal) variable of textual behavior, commonly called reading. Skinner defined a reader as a “speaker under the control of a text” (1957, p. 65). Other visual stimuli that control textuals include pictures, pictograms, phonetic symbols, hieroglyphs, Braille, and other visual forms that evoke textuals. In reading, printed stimuli are covertly or overtly named, but are not described, and for this reason, textuals are said to be functionally equivalent to the proper name of the stimulus (printed characters, words, other symbols). The stimulus control is precise, or there will be defective textuals (misreading). Michael (1982) suggests the term codic to include textual and to appropriately extend this type of verbal operant to taking dictation. In both the textual and dictation taking, the stimulus is verbal, although the verbal stimulus for the textual is print and the verbal stimulus for dictation taking is vocal. The response form, however is different; it is reading—a vocal response in the case of the textual and writing—a motoric response in the case of dictation taking. Skinner’s analysis of the textual and the more recent extensions (see Michael, 1982, 1985; E. Vargas, 1982, 1988) include such varied phenomena as self-textuals (“making notes to oneself”), transcription, writing, copying printed material, and so forth. Thus, the Skinnerian analysis is more complete than the fragmented linguistic analysis of phonologic, semantic, grammatic, morphologic, and literacy skills. Clinical Implications 102 SLP- ABA Volume 5, Issue No. 2 Treating reading and writing disorders is now within the scope of practice of SLPs. In recent times, attention has been drawn to the concept that reading and writing skills are language-based. It may have taken this long to recognize this simple fact because of the linguistic model SLPs have been following. The transformational generative linguistics paid little or no attention to reading and writing. Skinner, however, had considered all aspects of VB since the 1940s, and his analysis of textuals offers a good starting point for planning remediation programs. Unfortunately, there is not much research in speech-language pathology on teaching textuals to children or adults. In behavioral journals (e.g., Journal of Applied Behavior Analysis, The Analysis of Verbal Behavior), clinicians can find ways of teaching reading and writings skills that are better based on experimental methods than are the literacy intervention approaches often described in SLP journals and textbooks. Space will not permit a more detailed examination of textuals as clinical treatment targets. It is, however, useful for SLPs to consider integrating textual training with speech-language training (Hegde & Maul, 2006). For example, pictures used to evoke (along with mands) VBs of specific topographic features (phonemes, words, phrases, sentences) may be accompanied with printed stimuli. When teaching the production of phoneme /b/ or the tact ball with the help of a stimulus picture, the clinician may have the word ball printed on the stimulus card. While evoking either an echoic ball or an evoked tact ball, the clinician also can point to the printed word ball to reinforce a textual response. If clinicians follow the VB approach to teaching reading and writing, they would avoid such ineffective procedures as teaching phonological awareness or teaching encoding and decoding skills, and such other unproven cognitivelinguistic approaches. Audience The listener is an important part of the contingency governing VB, which typically occurs only in the presence of other individuals who reinforce it. The term audience refers to an effect on verbal operants that listeners (audience) have. Therefore, audience is not a class of verbal operants like the ones described so far. An audience is defined as “a discriminative stimulus in the presence of which verbal behavior is characteristically reinforced and in the presence of which, therefore, it is characteristically strong” (Skinner, 1957, p.172). An audience may determine all that is said on a given occasion, although this happens infrequently. Audience is usually a supplementary variable; its effects are additive to the strength of other primary variables. As a supplementary variable, an audience may have two kinds of effects. First, audience may determine such production effects as audibility of utterances. On such occasions, the audience may not have any effect on what is being said, only on how it is said. A strong primary variable makes speech very probable, but normally it will be uttered aloud only in the presence of an audience. In certain other social situations, strong primary variables of speech may be absent, so that people confronting each other “do not have much to say.” The presence of each other, however, might constitute a strong audience effect (strong discriminative stimuli for speech). People then talk about the weather or do “small talk.” An opposite effect is seen when the audience present is too weak, and the primary variables are very strong. The person is “itching” to speak but confronts a wrong kind of an audience—the one that has not been associated with reinforcement in the past. The speaker may nevertheless blurt out something, and then may hastily add “please don’t mind, I am just bubbling today.” Second, as a supplementary variable, an audience may partly determine what is being said, although some politicians may be accused of saying all that is said because of an audience. When an audience becomes a part of controlling variables, its effect is usually to select a particular response. The presence of a single primary variable raises the probability of the emission of several verbal responses that are typically conditioned to it. The audience present may determine which one of these actually gets said. After having tested a child, a language clinician is likely to respond with different sets of words to describe the “problem” depending on whether the listener is a junior student in speech 103 SLP- ABA Volume 5, Issue No. 2 pathology, a graduate student, a fellow co1league, or the mother of the child. People who are bilingual switch languages depending on their audience. Among themselves, professions emit their own jargon, and peer groups emit their slang. These are all instances of audience control of what is being said. Clinical Implications For the most part, SLPs initially establish verbal operants in the clinic. As they teach various verbal skills to their clients, they also serve as the initial audience for the clinically established VBs. Consequently, the clinicians become discriminative stimuli for the clinically established VBs. Unless the clinicians take additional steps, other people the clients encounter may not evoke the newly established VBs because their discriminative stimulus function is not yet established. This is often described a problem of generalization; but it is indeed a problem of lack of required additional conditioning of VBs to audience other than the clinician (Hegde, 1998). To overcome that problem, clin icians usually bring other people, including family members, into the treatment sessions. Fellow clinicians also may take part in treatment sessions. The clinician may move treatment sessions to more natural settings where additional people serve as audience for the newly established verbal skills. In essence, audience generalization is a matter of transferring the stimulus control from clinician to other persons with whom the client regularly interacts. Multiple Causation of Verbal Operants Motivation (causing mands), environmental events (causing tacts), another speaker’s speech (causing echoics), printed or other visual stimuli (causing textuals), one’s own speech (causing intraverbals) and the audience (producing an effect on those verbal operants) exemplify the six kinds of stimulus control of the first five kinds of verbal operants. These controlling variables do not exert their influence in isolation, however. Typically, several variables concurrently control the same verbal operant, and different sets of variables control different operants. Consequently, (1) a single variable evokes (causes) multiple responses, (2) multiple variables evoke a single response, and, (3) different classes of verbal operants constitute single utterances. Only in echoics (duplics) and codics (textuals and dictation taking) do we see single variables controlling their respective single responses. That a single variable controls more than one response is the basis of much of the speech emitted in relatively constant environments. People do not need a parade of stimulus events to talk for extended periods of time. One variable is sufficient to generate much speech, which serves as stimuli for more speech (intraverbal control). Therefore, there is hardly any dearth of stimuli. In fact the problem might be to explain how certain responses, though probable, do not get emitted and how the responses that were emitted got selected. Skinner (1957) rejected the mentalistic idea that speakers choose their words, because it creates a more difficult problem: explanation of an elusive choosing process and an inner speaker who chooses. Instead, Skinner proposed that the number and strength of variables present in a given situation determines the selection of verbal operants. The effects of two or more controlling variables are additive. For a specific response, therefore, the greater the number of currently active variables, the higher the probability of its occurrence. However, a few stronger variables with a longer history of reinforcement may exert greater influence on response selection than several weaker variables with defective or recently instituted contingencies. Additional supplementary strengthening in the form of specific audience effects is also a source of response selection. On the basis of multiple causation, Skinner described different kinds of supplementary strengthening and explained various kinds of neologism, intrusions, slips, and distortions in speech. Different classes of verbal operants, such as tacts, mands, and intraverbals are often parts of a single utterance. The utterance, Fool! You think I am a fool? contains an echoic and a tact. Attention, 104 SLP- ABA Volume 5, Issue No. 2 kids! contains a mand and an audience effect. The mand, May I have a large cup of strong coffee also contains multiple tacts (large, cup, strong, coffee) and autoclitics (a, of). Clinical Implications Except at the very basic level, VB training involves multiple verbal operants. Pure mands or pure tacts, though rare, may be taught with limited response topography (words, phrases). Teaching children to say cookie, sock, or book as either a mand or a tact may be initially necessary, but excessive training at this level will make it difficult to shift training to more complex verbal operants. More importantly, the simpler and purer verbal operants will not be as effective as the more complex verbal operants in modifying the listener responses. Response complexity may be increased only by including different verbal operants into single utterances. The traditional sentence typic ally is a combination of multiple verbal operants, including autoclitics, described in the next section. Conversational skills training—a high level of verbal training— will include, in different combination, mands, tacts, partial or full echoics, self-echoics, autoclitics, and intraverbals, as noted previously. Autoclitics: Grammar and More In Skinner’s (1957) analysis , mands, tacts, intraverbals, echoics, textuals, and audience effects are primary verbal behaviors, which do not include grammar and word order. This position contrasts with the Chomskyan linguistic theory in which grammar is primary, and has the status of an independent variable in that an innate grammar is essential for language development. However, Skinner did not ignore word order and grammar. None of the abundant linguistic criticisms have come to grips with the subtleties of Skinner’s analysis of grammar and word order. According to Skinner (1957), grammar and word order are secondary to the primary verbal operant classes described previously. Grammar is secondary to first having something to say. Without a repertoire of primary verbal operants, a speaker has no use for grammar (including word order). Therefore, word order and grammatical features are dependent variables. They describe certain effects, not causes. Skinner described the secondary processes of grammar and word order under the term autoclitic. The term, however, includes several verbal phenomena not included under the linguistic analysis of grammar and word order. Skinner wrote that “part of the behavior of an organism becomes in turn one of the variables controlling another part” (1957, p. 313), and that “parts of language deal with other parts of language” (1957, p. 341). In other words, some verbal operants discriminatively tact other verbal operants. Thus, when we “tact our own verbal behaviors, including its functional relationships” (Skinner, 1957, p. 314), we have autoclitics. As they talk, people tell their audience how, what, and why they talk; they fine-tune the listener reactions by making specific comments about their speech. Such specifications of what, why, and how speech is being emitted are autoclitics, which include grammatical features. In essence, autoclitics include speech about speech, the controlling variables of speech, or specifications of certain aspects of stimuli that prompted speech. It is in this sense that autoclitics are secondary VBs controlled by other, primary, VBs. Primary VBs are the controlling part; autoclitics are the parts controlled. Both are VBs, but autoclitics are not controlled by those that control primary VBs (e.g., motivation and physical stimuli). It has been noted that the term autoclitics includes not only grammatical words and word order, but many other kinds of verbal responses that are traditionally not included under grammar. Responses such as I said, I see, in other words, certainly, perhaps, are all autoclitics too. Any part of an utterance which discriminatively tacts any aspect of the controlling variables and their relatio n to primary operants is an autoclitic. Varieties of Autoclitics 105 SLP- ABA Volume 5, Issue No. 2 Autoclitics are of different kinds. A large group of them are descriptive. “I said . . .,” is an autoclitic which describes the speaker’s prior verbal responses, while I was about to say describes an imminent response. Some of the descriptive autoclitics tact the controlling variables of the verbal operants they accompany. A statement such as the President is in Copenhagen may be made for any one of several reasons. But if the speaker, reading a newspaper, adds I see to that statement, the listener knows why the speaker said what he or she did. In other words, the controlling variable of the statement (the printed story in the newspaper) is tacted for the benefit of the listener. The same state ment, when preceded by Tom said (that the President is in Copenhagen) identifies a different variable controlling the primary VB. A number of autoclitics specify the strength of the VBs they are a part of. Autoclitics like I guess, I imagine, indicate that what follows in each case is not very strongly determined, where as I am certain that, I know for sure that, indicate that subsequent responses have strong controlling variables. Although the primary VBs (the responses that follow or accompany those autoclitics) are the same, the effects on the listener are not. Thus, different autoclitics modify listener reactions in specific ways. Autoclitics like I hate to say tact the emotional state of the speaker, while those like I agree, and I should say describe the relation between the response and other VB of the speaker or listener, or the situation in which the behavior occurs. Some autoclitics qualify responses they accompany, and include negation and assertion. The linguistic analysis of negation implies that the absence of previously experienced objects is the source of negation. But as Skinner says, this is “clearly impossible in a causal description” (1957, p. 322), because a thing that does not exist cannot cause anything. If the response no rain is controlled by the absence of rain, “why do we not emit a tremendous flood of responses under the control of the absence of thousands of other things?” (Skinner, 1957, p. 322). In the example no truck discussed earlier, no is an autoclitic controlled by the verbal operant truck , which is in turn controlled not by its absence, but by the presence of stimuli, which, on previous occasions, accompanied the object truck. The response she is not Swedish contains the autoclitic not, which is controlled by she and Swedish, both made likely by primary variables. In this case, not implies that Swedish is not a part of the tact for she. Put differently, not implies that the controlling variables for the two tacts, she and Swedish do not covary and have not been reinforced as a verbal operant. The most common assertive autoclitic in English is is. It tells the listener something about the causal variables of responses and the relationship among them. The verbal response that chair is big contains two tacts and the autoclitic is. The autoclitic specifies that the same discriminative stimulus controls both that chair and big. In other situations, is is also controlled by the temporal characteristics of the stimulus. The English auxiliaries is and was assert relationships between responses, and responses and their antecedents, but different temporal aspects govern their emission. Technically, assertive autoclitics imply that the operants involved are either tacts or intraverbals. Mands, echoics, and textuals are not typically asserted. Quantifying autoclitics tact the numerical properties of the controlling stimuli that prompted a primary verbal response. The articles the and a specify the relationship between responses and their controlling variables in two ways. They tact the numerical properties of the controlling variables, their specificity, or both. The definite article the literally points at the controlling variable of the response it accompanies. The articles also make it possible to obtain a more precise response from the listener. Other autoclitics like all, some, few, mostly, one, many and so forth are similar: they specify the numerical properties of discriminative stimuli and their relation to verbal operants. A number of fragmentary tacts, which are autoclitics, appear in the form of grammatical tags, inflections, or bound morphemes. Tags like -s, -ed, and -ing (e.g., spills, spilled, and spilling) tact the temporal relationship between the controlling variables and the speaking. Possessive inflection -s, on the other hand, tacts the controlling relationship between two tacts in the same utterance. They also inform the listener that the discriminative stimuli for the two tacts (boy’s hat) are likely to covary. The two 106 SLP- ABA Volume 5, Issue No. 2 conjunctions and and or imply that more than one verbal operant is being controlled by the same discriminative stimulus. In the case of and, however, the two operants are compatible in relation to their single stimulus (small and beautiful). In the case of or the two operants are not compatible (genius or crock). Most, but not all, prepositions tact the spatial relationships between the controlling variables of verbal operants. When a speaker says I heard the sound of music, the autoclitic of discriminatively tacts the variable responsible for the sound. Sound could be of anything, and consequently, as a verbal response, sound could be controlled by any one of several variables. The autoclitic of discriminatively tacts the specific controlling variable of a current verbal response. No attempt will be made in this paper to catalog all grammatical words and tags in terms of their autoclitic function. The point is that grammar can be accounted for in terms of a causal analysis as against the structural analysis. One final question, however, needs to be considered: Why do autoclitics occur at all? Why do speakers tact the controlling variables of their own VB? Clearly, the speakers need not tact the controlling variables for their own sake, because they already are in touch with them, or else they would not speak. It is often the listener who has no access to the speakers’ controlling variables. Therefore, listeners ask questions like when, where, how many, how sure are you, why do you say that, and so forth. Parts of answers to such mands (questions) are autoclitics. In sum, autoclitics occur for the benefit of the listener, who needs to know, (1) why an utterance is made, (2) how strong is that utterance (operant strength), and (3) what temporal, spatial, physical, quantitative, and other properties of stimuli govern that utterance. The precision of listener reaction depends on this kind of information. An imprecise listener reaction is a defective contingency for the speaker. In the final analysis, therefore, the speaker is a beneficiary too. In Skinner’s analysis, ordering (syntax) seen in verbal responses is also partly due to the autoclitic process. But there are other causal variables that help order VB. Some ordered VB may not involve an ordering process at all. For example, the child may initially learn phrases like hi there, how are you, fine, thank you and so on as single functional entities. For adults, too, utterances such as have a nice day may be single functional units, not involving an ordering process. In some situations, word order may correspond to the sequence of relevant stimuli that generate verbal responses. For instance, a TV sports commentators’ speech is temporally ordered according to the order in which the events (stimuli) unfold in front of them. Order may also be due to the order in which verbal stimuli generate more verbal responses, as in the responses given to free association test items and in all intraverbals (e.g., reciting the alphabet or a number series). This suggests that intraverbal control is one of the multiple sources of order (syntax). Order in echoic responses is due to the order in which the antecedent stimuli are generated for the speaker. Yet another source of order is the relative strength of responses, because the strongest is more likely to be emitted first, and the weakest the last, and thus an order would emerge (Skinner, 1957). When a speaker says “Hand me that book, the red one,” the order of the verbal operants may be partly determined by their relative strength. Possibly, the main mand part of it (“Hand me [that] book”) was stronger than the tact part of it; a weaker tact (“[the] red one”) was added because the mand was not effective in generating a quick and correct response from the listener. Clinical Implications Educational teaching of elements of autoclitics to children is as old as education itself; elementary schools were once called grammar schools. Initial treatment efficacy studies on teaching grammatical morphemes to children with language disorders were published in the late 1960s and early 1970s. Such studies, however, were conducted by applied behavior analysts (e.g., Guess, Sailor, Rutherford, & Baer, 1968; Schumaker & Sherman, 1970). Subsequently, studies on teaching grammatic morphemes as well as syntactic structures began to appear in SLP journals (see Bricker, 1993 and Hegde, 1998 for historical reviews of treatment research on teaching grammatical elements to children with language disorders). Unfortunately, whether the research was conducted by applied behavior analysts or SLPs, the authors did 107 SLP- ABA Volume 5, Issue No. 2 not describe the treatment targets in terms of verbal operants; many investigators have, and continue to use, the linguistic terms to describe the skills taught to children with language disorders. The methods of teaching and the research designs in which the treatment efficacy was evaluated were all behavioral, however. This state of affairs continues, even in some explicitly behavioral journals (e.g., Journal of Applied Behavior Analysis). Articles published in The Analysis of Verbal Behavior are exceptional in using both the verbal behavior concepts and behavioral treatment. In a later section of this paper, I will describe selected clinical research on autoclitics (especially the grammatical morphemes) that has shed light on verbal operant response classes. Teaching various sentence forms as SLPs conceptualize it will always involve autoclitic responses. Conversely, teaching specific grammatical morphemes often (though not always) involve sentences. For instance, to teach the verbal auxiliary is, the clinic ian needs sentences (combined or ordered verbal operants of different classes): The boy is running, The girl is smiling, and so forth (Hegde, 1980). The response class research, briefly reviewed in a later section, suggests that it is more efficient to target Skinner’s autoclitics and other verbal operants rather than the linguistic categories. As teaching various grammatical elements is a significant part of teaching VBs to children with language disorders, it is hoped that SLPs will begin to adopt Skinner’s functional units rather than the linguistic structural units in assessment (see Esch’s article in this issue) and treatment. Receptive Language? Linguistically and popularly, an appropriate response to a verbal stimulus is often described as receptive language or comprehension. In the behavioral analysis, the terms receptive language and comprehension are even more questionable than the term language itself. The implication that a listener passively “receives” and “understands” (or “processes the signal,” as in the popular computer analogy) spoken language or read material altogether misses the point of verbal behavior, which constitutes actions of speakers and listeners. Typically, appropriate behavior to verbal stimuli is the basis to assume a mentalistic notion of comprehension, which remains unexplained and unobserved. What is observed is either a reinforceable (appropriate) verbal or a nonverbal response to verbal stimuli. In the case of clients who have obviously limited verbal repertoire, clinicians test comprehension by sampling a correct (reinforceable) nonverbal response to verbal stimulus. Typically, the client is manded (asked) to point to the named stimulus embedded in a stimulus set. If there is a conventional correspondence between the mand, the pointing, and the physical stimulus, the clinician reinforces the pointing response. Thus, in a behavioral analysis, comprehension is an unnecessary term that skirts the valid stimulus-responsereinforcement contingency that is adequate to handle the relevant observations. In an extension of Skinner’s analysis, Michael (1985) suggests that VBs of pointing at, touching, and in responding in other nonverbal ways to verbal stimuli may be called stimulus-selection-based VB. Although teaching stimulus sele ction (comprehension or receptive language) as a precursor to VB teaching to most children with speech or language disorders is unnecessary, such a teaching is a part of augmentative and alternative intervention for adults and children with limited verbal repertoire. Michael calls the more typical forms of verbal (as well as vocal) behavior topography-based because, for instance, the words dog and cat have different response topographies, whereas stimulus-selection-based VB (e.g., pointing) remains constant regardless of the object pointed to. Language Treatment Research Supports the Behavioral Analysis Traditionally, SLPs have relied on structural analysis of language, in which the independent variables are either ignored or assumed to take the form of innate devices, mental schemes, mental images, cognitive concepts, maps, and other presumed entities with little or no empirical validity. As applied scientists, however, SLPs need to intervene in a behavioral process that for some reason has been impaired. They have to produce changes in the language behaviors of their clients. Changes in behaviors 108 SLP- ABA Volume 5, Issue No. 2 can be produced only when their causal variables are under the clinician’s control. In this sense, SLPs are more like empirical scientists than structural nativists. Because the variables figured in the structural analysis are mentalistic and nonmanipulable, SLPs have turned to behavioral intervention for communication and swallowing disorders (Hegde, 1998). Behavioral intervention is also a causal analysis of behaviors, however. Its success as an applied technology depends on its emphasis on a causal analysis of normal or impaired VBs. Whenever some new behavior is clinically modified, the applied technology throws some light on the basic analysis of that behavior. Treatment Targets Should be Functionally Organized Clinical research data in treating language disorders in children, published both in the behavioral and speech-language pathology literature, has produced some impressive results that support Skinner’s functional units (verbal operants), as against the structural (linguistic) categories. For instance, the VB approach to language intervention has shown that, as Skinner asserted, mands and tacts are functionally independent verbal operants, in the sense that teaching tacts will not automatically result in the production of mands or vice versa (Hall & Sundberg, 1987). Many SLPs know, for instance, that a child who is taught to say “Ball” (a tact) when shown a ball will not automatically produce “I want ball” (a mand). The child who has learned to mand a ball will not necessarily tact it; both need separate training. Interestingly, functional (causal) independence of verbal operants has been demonstrated with chimpanzees (SavageRumbaugh, 1984) and pigeons (Michael, Whitley, & Hesse, 1983; Sundberg, 1985). In language treatment research conducted by both behavior analysts and SLPs, functional response classes that contradict the validity of structural categories have emerged when (a) what linguists consider separate grammatic structures did not need separate training and (b) when what is considered a single grammatical structure broke down into different response classes that needed separate training. For instance, treatment research has demonstrated that such single linguistic categories as (a) the regular plural (Guess, et. al., 1968), (b) the irregular plural (Hegde & McConn, 1981; Hegde Noll, & Pecora, 1979), (c) the regular past tense (Schumaker & Sherman, 1970), and (d) the irregular past tense (Hegde & McConn, 1981; Hegde Noll, & Pecora, 1979) are each a collection of multiple and functionally independent response classes (see Hegde & Maul, 2006, for a summary of research). Independent response classes need separate training as there is no or socially accepted generalization across functional response classes. Treatment research also has demonstrated that such multiple linguistic categories as (a) the subject-noun and object-noun phrases (McReynolds & Engmann, 1974) and (b) the English auxiliary and copula (Hegde, 1980) are not functionally independent; teaching one of the two will instate the other, regardless of which one is taught. These two studies have used the more powerful ABAB experimental design than the typical teach-one-and-probe-the-other method; one of the two skills was taught, then reversed, and finally reinstated to show that the untaught skill is produced, reversed, and reinstated without training. Essentially, under a causal-experimental analysis, some linguistic distinctions collapse into single functional units and other single structural units break into multiple functional units. Although more research on operant verbal response classes is needed, clinical research designed to remediate deficient language skills supports Skinner’s (1957) figurative comment that when “language” is dropped to the floor, it may break into verbal operants, not linguistic structures. Summary and Conclusions Skinner’s is primarily a cause-effect analysis of VB. His main concern was to describe the controlling variables of verbal operants. Accordingly, he described six kinds of stimulus control and five kinds of verbal operants: motivation (causing mands), environmental events (causing tacts), another 109 SLP- ABA Volume 5, Issue No. 2 speaker’s speech (causing echoics), printed or other visual stimuli (causing textuals), one’s own speech (causing intraverbals) and the audience effect (not a class of verbal operants, but producing an effect on other verbal operants). Skinner described a secondary process called autoclitics that included grammar and other related phenomena. He proposed that VBs are multiply determined and most everyday utterances are a combination of multiple verbal operants. SLPs receive better training in the linguistic view of language than the behavioral view. The textbooks and other sources they read routinely distort the Skinnerian analysis and repeat Chomsky’s misunderstood and misplaced criticism of Skinner’s Verbal Behavior, even as Chomsky’s theories have faded and Skinner’s natural science approach and behavioral treatment have been gaining worldwide respect. The critics of the behavioral view have an ethical responsibility to first understand Skinner’s analysis before making critical comments. SLPs have successfully used the behavioral intervention procedures because linguistics does not describe independent variables that are manipulated in what we call treatment (Hegde, 1998). If the SLPs also adopt a functional (cause-effect) analysis of VBs, they would then be internally more consistent with their concepts and treatment methods. Treatment research in child language disorders has generally supported Skinner’s view that VB is not organized structurally, but functionally. I conclude with a personal epilogue. Many years ago, a distinguished clinical scientist and a friend of mine, Leija McReynolds, then professor at University of Kansas, was visiting me for a few days. After she gave a lecture at California State University-Fresno, and before she left for Stanford University where she was spending her sabbatical year in the Linguistics Department, asked me a sharp question in the campus parking lot: “Giri, do you think the influence of linguistics on us SLPs has been detrimental?” I said “Yes,” she smiled gently as she got into my car, and I drove her to the airport. Professor McReynolds (along with Engmann) showed for the first time in SLP that when subjected to an experimental analysis using the single -subject ABAB research design, the grammatically distinct subject noun and object noun phrases collapse into a single functional unit. References Adelman, B. E. (2007). An underdiscussed aspect of Chomsky (1959). The Analysis of Verbal Behavior, 23, 29-34. Anderson, J. (1991). 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H., & King, A. P. (2006). Mothers provide differential feedback for infants’ prelinguistic sounds. International Journal of Behavior Development, 30, 500-516. Guess, D., Sailor, W., Rutherford, G., & Baer, D. M. (1968). An experimental analysis of linguistic development: The productive use of the plural morpheme. Journal of Applied Behavior Analysis, 1, 225-235. Hall, G., & Sundberg, M. L. (1987). Teaching mands by manipulating conditioned establishing operations. The Analysis of Verbal Behavior, 5, 41-53. Harris, R. A. (1993). The linguistics wars. New York: Oxford University Press. Hegde, M. N., Noll, M. J., & Pecora, R. (1979). A study of some factors affecting generalization of language training. Journal of Speech and Hearing Disorders, 44, 301-320. Hegde, M. N. (1980). An experimental-clinical analysis of grammatical and behavioral distinctions between verbal auxiliary and copula. Journal of Speech and Hearing Research, 23, 864-877. Hegde, M. N., & McConn, J. (1981). 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Language disorders in children: An evidence-based approach to assessment and treatment. Boston, MA: Allyn and Bacon. Jakobson, R. (1968). Child language, aphasia and phonological universals (A. R. Keiler, Trasn.). The Hague, The Netherlands: Mouton. Keller, F. S., & Schoenfeld, W. N. (1950). Principles of psychology. New York: Appleton, Century, Crofts. 111 SLP- ABA Volume 5, Issue No. 2 Leigland, S. (2007). Fifty years later: Comments on the further development of a science of verbal behavior. The Behavior Analyst Today, 8, 336-345. MacCorquodale, K. (1969). B. F. Skinner’s Verbal Behavior: A retrospective appreciation. Journal of the Experimental Ana1ysis of Behavior, 12, 831-841. MacCorquodale, K. (1970). On Chomsky’s review of Skinner’s Verbal Behavior. Journal of the Experimental Ana1ysis of Behavior, 13, 83-99. McGill, P. (1999). Establishing operations: Implications for the assessment, treatment, and prevention of problem behavior. Journal of Applied Behavior Analysis. 32, 393-418. McLaughlin, S. (2006). Introduction to language development (2nd ed.). Clifton Park, NY: Cengage Delmar. McLeish, J., & Martin, J. (1975). Verbal behavior: A review and experimental analysis. The Journal of General Psychology, 93, 3-66. McReynolds, L. V., & Engmann, D. L. (1974). An experimental analysis of the relationship between subject and object noun phrases. (ASHA Monograph # 18.) In L. V. McReynolds (Ed.), Developing systematic procedures for training children’s language (pp. 30-46). Rockville, MD: American Speech-Language-Hearing Association. Michael, J. (1982). Skinner’s elementary verbal relations: Some new categories. The Analysis of Verbal Behavior, 1, 1-3. Michael, J. (1985). Two kinds of verbal behavior plus a possible third. The Analysis of Verbal Behavior, 3, 1-4. Michael, J. (1988). Establishing operations and the mand. The Analysis of Verbal Behavior, 6, 3-9. Michael, J. (2000). Implications and refinements of the establishing operation concept. Journal of Applied Behavior Analysis. 33, 401-410. Michael, J., Whitley, P., & Hesse, B. E. (1983). The pigeons parlance project. The Analysis of Verbal Behavior, 2, 6-9. Mowrer, O. H. (1952). The autism theory of speech development and some clinical applications. Journal of Speech and Hearing Disorders, 17, 263-268. Miguel, C. (2009). Editorial: The verbal behavior approach. The Analysis of Verbal Behavior, 25, 1-3. Osgood, C. E. (1963). On understanding and creating sentences. American Psychologist, 18, 735-751. Owens, R. E., Jr. (2005). Language development: An introduction (6th ed.). Boston, MA: Allyn and Bacon. Palmer, D. (2006). On Chomsky’s appraisal of Skinner’s Verbal Behavior: A half century of misunderstanding. The Behavior Analyst, 29, 253-267. Pena-Brooks, A., & Hegde M. N. (2007). Assessment and treatment of articulation and phonological disorders in children (2nd ed.). Austin, TX: Pro-Ed. Reichle, J., & Wacker, D. P. (1993). Communicative alternatives to challenging behavior: Integrating functional assessment and intervention strategies. Baltimore, MD: Brookes. Richelle, M. (1976). Formal analysis and functional analysis of verbal behavior: Notes on the debate between Chomsky and Skinner. Behaviorism, 4, 209-221. 112 SLP- ABA Volume 5, Issue No. 2 Sautter, R. A., & LeBlanc, L. A. (2006). Empirical applications of Skinner’s analysis of verbal behavior with humans. The Analysis of Verbal Behavior, 22, 35-48. Savage-Rumbaugh, S. E. (1984). Verbal behavior at a procedural level in the chimpanzee. Journal of the Experimental Analysis of Behavior, 43, 223-250. Schlinger, H. D. (2008a). The long-good-bye: Why B. F. Skinner’s Verbal Behavior is alive and well on the 50th anniversary of its publication. The Psychological Record, 58, 329-337. Schlinger, H. D. (2008b). Listening is behaving verbally. The Behavior analyst, 31, 145-161. Schoneberger, T. (2000). A departure from cognitivism: Implications of Chomsky’s second revolution in linguistics. The Analysis of Verbal Behavior, 17, 57-73. Schumaker, J., & Sherman, J. A. (1970). Training generative verb usage by imitation and reinforcement procedures. Journal of Applied Behavior Analysis, 3, 273-287. Skinner, B. F. (1957). Verbal behavior. New York: Appleton Century. Smith, R. G., & Iwata, B. A. (1997). Antecedent influence on behavior disorders. Journal of Applied Behavior Analysis. 28, 515-535. Staats, A. W. (1968). Learning, language, and cognition. New York: Holt. Sundberg, M. L. (1985). Teaching verbal behavior to pigeons. The Analysis of Verbal Behavior, 3, 11-17. Taylor, B. A., Hoch, H., Potter, B., Rodriguez, A., Spinnato, D., Kalaigian, M. (2005). Manipulating establishing operations to promote initiations toward peers in children with autism. Research in Developmental Disabilities, 26, 385-392. Vargas, E. A. (1982). Intraverbal behavior: The codic, duplic, and sequelic subtypes. The Analysis of Verbal Behavior, 1, 5-7. Vargas, E. A. (1988). Verbally-governed and event-governed behavior. The Analysis of Verbal Behavior, 6, 11-12. Vargas, J. S. (2009). Behavior analysis for effective teaching. New York: Rutledge. Virues-Ortega, J. (2006). The case against B. F. Skinner 45 years later: An encounter with N. Chomsky. The Behavior Analyst, 29(2), 243-251. Winokur, S. (1976). A primer of verbal behavior: An operant view. Englewood Cliffs, NJ: Prentice-Hall. Author Contact Information M.N. Hegde, Ph.D. California State University Postal: 1948 Ashcroft Avenue, Clovis, CA 93611 E-mail: [email protected] 113 SLP- ABA Volume 5, Issue No. 2 Verbal Behavior by B.F. Skinner: Contributions to Analyzing Early Language Learning Scott F. McLaughlin Abstract B.F. Skinner’s Verbal Behavior (1957) is analyzed in the context of early language learning. In the book, Skinner did not emp hasize the foundations for language learning in infants and young children. His principles and concepts are integrated with current knowledge of caregiver-infant interactions. Several major elements of his functional analysis are described as well as relevant verbal operants. These are correlated with terms and concepts used in classical and contemporary research in child language. Keywords: Verbal behavior, caregiver-infant interaction, language learning, antecedents, consequences, selective reinforcement, functional analysis, contingency shaped behavior, verbal operants, mands, echoics, tacts, autoclitics Introduction Two pieces of literature appeared quietly and without fanfare in 1957. Each book inalterably affected how we have come to view language, human behavior, and language learning. In 1957, Noam Chomsky published Syntactic Structures (1957), his germinal work that established the foundations of psycholinguistics. This work, in combination with a second publication, Aspects of the Theory of Syntax (Chomsky, 1965), broadly influenced research in linguistics and the theoretical relationships between the mind and language. Together, they represented a firm anchor point on one end–the nativistic end–of the philosophical continuum established in 1957. With regard to explaining language development, one of the more publicized features of this theory was the Language Acquisition Device, or LAD. Although there was no intention to correlate this “device” to any underlying neurological structure, Chomsky proposed the LAD as the presumed innate mechanism in the human brain (or mind) to explain the apparent ease and rapidity with which children acquire language. Although the concept of the LAD has been modified through the years, in the 1960s it became the widely accepted explanation for children’s acquisition of language, largely removing caregivers from any active role in their children’s language abilities. The opposite anchor point–the behavioral end–on this philosophical continuum was established that same year, when B.F. Skinner published Verbal Behavior (1957). (See Hegde, in this issue, for a comprehensive review of Skinner’s Verbal Behavior.) In contrast to Chomsky’s approach, Skinner proposed an analysis of verbal behavior based on a natural science account of behavior that had evolved since the earlier publication of his The Behavior of Organisms (1938). In Verbal Behavior, Skinner applied a functional analysis approach to analyze language behaviors in terms of their natural occurrence in response to observable environmental circumstances and the measurable effects they have on human interactions. In this view, language was characterized as the result of, as opposed to the reason for, complex human behavior. The complexities of language do not exist prior to or independent of human behavior; instead the complexities of language behavior reflect our capacity to respond verbally to the complex and subtle intricacies inherent in human experiences and interactions. In Verbal Behavior, Skinner (1957) did not emphasize explaining the nature of early language development; perhaps the explanation seemed obvious to him from the fact that he had invoked an operant model in the overall analysis. Verbal Behavior primarily focused on an explication of the causal variables for the verbal interactions of accomplished speakers and listeners whose learning histories were in place and preceded the verbal behaviors in question–in essence, adult speakers. It is perhaps unfortunate that Skinner emphasized this level of analysis–adult verbal interactions–throughout Verbal Behavior as it ostensibly posed difficulty for some who have tried to explain the development of language 114 SLP- ABA Volume 5, Issue No. 2 under his model. Chomsky critiqued Skinner’s functional analysis in a book review that many found puzzling due to several lengthy criticisms put forth by Chomsky that did not relate to principles or concepts contained in Verbal Behavior. Specifically, Chomsky criticized Skinner for proposing imitation and conscientious parental tutoring as the major explanations for language development. Chomsky also took Skinner to task for his supposed reliance on memorized Markovian chains as an explanation for grammar. However, none of these elements were included in Skinner’s model. Over the years, attempts to describe how Skinner’s model might be applied to children’s language development, including recent sources (Owens, 2005; Berko Gleason, 2005; Hulit, 2006), have continued to rely on perpetuating these misconceptions contained in Chomsky’s (1959) “bewildering” (MacCorquodale, 1970, p. 83) critique of Verbal Behavior. However, others (McLaughlin, 2006; Winokur, 1976) have attempted to provide integrated explanations of early language learning that are more consistent with the original principles set forth in Verbal Behavior (1957). This paper will revisit some basic terms and concepts central to understanding the functional analysis set forth by Skinner (1957). In the context of early language learning, these elements will be explored as to how they relate to our understanding of language learning in young children, with particular emphasis on the foundations laid down in the first months and years of life. Finally, Skinner’s basic classifications of verbal behaviors–verbal operants–will be described and correlated with traditional concepts and research from language development literature. The Foundational Contingency: Infant-Caregiver Interactions According to Skinner (1957), a functional analysis of verbal behavior must build on the fundamental task of describing the behaviors of interest and then extend itself to explaining the causes of those behaviors. Such an analysis attempts to identify the variables that cause certain verbal behaviors to occur in certain circumstances. In the same way that one might say combustion is increasingly likely as a function of the combined presence of fuel, air, and heat, one might say that certain verbal behaviors are dependent upon, or occur as a function of, certain causal variables. The interrelationship of multiple and complex variables that influence verbal behavior comprises the contingenc ies that are established through a learning history–even though sometimes quite momentary–in which the setting, a behavior, and the consequences that have attended to the behavior influence the likelihood that the behavior will occur again in similar circumstances. In the context of language learning, analyzing the independent variables–the causes–is no simple proposition. To say that human beings are complex in their functioning is probably less a platitude than an understatement. Furthermore, developing humans–from infancy through childhood–are especially complex due to the multitude of concurrent changes that occur so rapidly during a relatively short period of time. There is the underlying physiological and neurological maturation that provides for an array of increasingly refined sensory and motor capabilities. Supporting and nurturing all these physiological changes requires the social interactions associated with caregivers’ routines and activities. Eventually, the child’s social interactions expand to an entire supporting cast of individuals with whom the child will interact in various settings and roles. In addition, the increasingly refined motor skills and the expanding and sophisticated social behaviors set the stage for new and more complex verbal behaviors to evolve. This is a process that is not only multifaceted; the various facets intertwine with and drive each other forward in the overall process. Although Skinner’s analysis is focused on the behavioral layer in all this development, it acknowledges that there is a myriad of accompanying genetic, neurophysiological, and social influences (Skinner, 1974). They simply do not occur at a level that can be included in this particular analysis. They no doubt exist and their potential roles would be addressed where necessary, but they are for the purposes 115 SLP- ABA Volume 5, Issue No. 2 of a functional analysis the inaccessible undercurrents that are left to other fields to explore and analyze. The functional analysis for the present purpose will confine itself to defining the roles of the antecedent setting events, consequences, and their influence on the onset and development of communication behaviors in infants and language learning in children. Antecedents for Infant Behaviors: The Stimulus Setting for Language Learning The antecedents of behavior are those stimuli or stimulus events that set the stage for behavior. Every moment that we experience contains a multitude of external stimuli that can be detected and internal stimuli that can be sensed at some level. As a result, any single stimulus or combination of stimuli has the potential to serve as the setting event for a response. If that response proves to be useful in some way that has reinforcing consequences, the stimulus that was present when reinforcement occurred becomes a discriminative stimulus for similar behaviors in the future. In our natural interactions in the “real world,” it is likely that more often than not, the combinations of stimuli that comprise a stimulus setting are more arbitrary, random, and coincidental than they are planned, staged, or contrived. Things just come together at times and present us with the occasion to respond in some way. External Stimuli. The human infant is immersed in stimuli from the beginning–even prior to birth. Although the fetal surroundings are darkened and relatively silent, it has been determined that the cochlea and auditory nerve have developed at around 26 weeks of gestation and the fetus is subsequently capable of detecting sound (Locke, 1993). The auditory system does have stimuli available to it, primarily in the form of the internal sounds of the mother’s heartbeat and blood flow. However, the mother’s voice is also detectable –albeit muffled–at conversational levels above this ambient noise. In this way, the fetus has several weeks of hearing at least the prosodic character of the mother’s voice, a sound that will be immediately associated with the most significant events in the first moments and days of the infant’s life following birth (Locke, 1993). At birth, the events that essentially integrate the social and functional nature of communication are present almost immediately. There is a significant convergence of human interaction in which caregivers begin to consistently (some might say constantly) provide for their infants’ very survival. Human infants are uniquely dependent on their caregivers for survival from the start and for several years following. Caregivers in turn provide for these needs through various interactions and routines that take on a strongly social character. It is critical to note that in this convergence (e.g., feeding sessions) the newborn’s first experiences are both life-sustaining and social by nature. As noted earlier, the infant’s auditory system is fully functioning at birth and the infant is probably already familiar with the mother’s voice patterns. Although his or her visual acuity is limited, stimuli within a foot are in fact visible to the infant. By the nature of most feeding sessions, the infant nestled in a feeding position at the breast, or in some similar placement if bottle fed, places the caregiver’s face and voice in perfect proximity to be intimately associated with feeding (Locke, 1993). This proximity and intimacy will persist as caregivers will need to assist with feeding for some time. As a result, this interaction, so vital for simple survival, consistently associates the caregiver’s face, voice, and physical contact with survival needs. As the earliest and most familiar stimulus setting for developing infants, this convergence of attention and social stimulation coincides with their most critical period of rapid brain growth and neurological maturation. This is a crucial principal in understanding the learning process that ensues. As Locke surmised, "One can hardly think of a developmental circumstance that would more favorably affect acquisition of complex behavior" (Locke, 1993, p. 264). Although most of the infant’s behaviors–eye gaze, hand movements, facial movements, and vocalizing–are primarily reflexive at first, they do coincide with the earliest most important routines that by their nature include the caregiver’s face and voice as conspicuous elements in the overall setting event. Most caregivers, at least in Western societies, are inclined to respond to their infants with eye gaze 116 SLP- ABA Volume 5, Issue No. 2 behaviors, hand play, and speech (often in some form of “motherese”) while the infant is being cuddled, bathed, dressed, and fed. Again, these earliest social experiences, repeatedly associated with the caregiving routines, become the foundational and consistent setting events for infants interacting with the world around them. Simultaneously, caregivers are at the center of their infants’ experiences as the most important source for survival and stimulation. As maturation progresses, infant motor behaviors–hand movements, facial expression, and so forth–become less reflexive and more voluntary and serve to initiate interactions in the context of routines and new forms of interaction with the caregivers. Beyond those earliest intimate experiences, with time the child’s developing motor system eventually permits exploring a wider territory, which includes a vast array of smells, textures, temperatures, shapes, colors, sizes, locations, actions, objects, persons, and relationships among them. This is hardly a complete list of the possible physical and functional features that could present themselves to any of us given the complexity of our world. As children grow, they become more adept at handling and exploring objects, more aware of the diverse events around them, and more responsive to the ways these all interact and relate to the significant people in their lives. All these very complex stimuli–both subtle and signific ant–become salient setting events for the development of an increasingly complex array of verbal behaviors. In other words, it would follow that the increasing complexity of the child’s verbal behavior correlates with his or her responses to increasingly complex stimuli and relationships in the environment. Internal Stimuli. Not all stimuli that contribute to setting events for verbal behavior are external. From birth, the infant experiences various states that presumably represent internal stimuli. Although the internal physiological stimuli cannot be directly observed, the process that prompts them to occur can be. The time period in which the infant is deprived of some basic need that results in the internal stimulus can be observed and measured. The length of time a child goes between feedings, the amount of time a child is uncovered and exposed to a chilly draft, or goes without social interaction would each be indicative of the degree of the corresponding internal states of hunger, cold, or loneliness (social deprivation) that may serve as motivation for the child’s subsequent behavior. Deprivation states can be real, accessible , and measurable variables when analyzing internal stimuli as antecedent events for certain behaviors in children. In early months, the overt behaviors may be purely physiological, reflexive, and strictly vocal in nature–for example, the hunger cry. Interestingly, caregivers respond differentially to negative vocalizations (whining, fussing, crying, and so forth) as opposed to pos itive vocalizations (cooing, babbling, laughing, and so forth). Negative vocalizations prompt more attempts at changing the infant’s physical state through tactile or positional changes. Caregivers tend to respond to positive vocalizations with vocal-verbal behaviors (Keller & Scholmerich, 1987). With the infants’ development of more precise verbal (as opposed to vocal) behaviors, a repertoire of overt responses that are more specific to different deprivation states and their underlying internal stimuli becomes possible and it would follow that caregivers would become more precise in responding verbally to address their children’s internal states (pain, hunger, cold, etc.). Consequences: The Nature of Reinforcement in Language Learning. The other major ele ment in the foundational contingency for language learning described by Skinner (1957) was the nature of consequences. On one level, that reinforcement probably plays a role at some level in verbal behavior would appear to be quite straightforward. Most may have a basic understanding of what constitutes reinforcement. However, a purely academic understanding that simply equates reinforcement to food and praise, or a knowledge of how clinicians explicitly and systematically reinforce target skills may hamper our ability to recognize the subtlety in caregiver-infant interactions. Appreciating the intricate strands of a reinforcement history that link the potency of the earliest experiences with the most basic reinforcers to the myriad of fleeting moments of social reinforcement that 117 SLP- ABA Volume 5, Issue No. 2 follow during the day-to-day caregiver-infant interactions is essential to understanding how language evolves from the earliest germinal moments in an infant’s life. Primary reinforcers. Reinforcers that have survival value–food, warmth, social contact–are considered primary reinforcers and are a normal part of care provided to most infants. Certainly the simplest and most obvious primary reinforcer is food. As with the youngest in any species, food plays a vital role as a primary reinforcer with survival value for human infants. However, it is perhaps even more crucial because human infants are entirely dependent on caregivers to provide this life sustaining primary reinforcer a number of times each day for several years. This earlie st contingency between caregiver responses and infant needs is vital to the infant’s survival and development. However fundamental it may be, providing for the infant’s survival is merely the first level of interconnection between infants and their caregivers. Secondary reinforcers. Secondary reinforcers are those stimuli or events that have the potential to reinforce behaviors due to their prior association with primary reinforcers. If a secondary reinforcer is established by being conditioned through association with a primary reinforcer, the social interactions noted previously that cause caregivers’ faces, speech, and physical contact to coincide with the delivery of food, by definition, should establish potent secondary reinforcers for an infant from the first day of life. Through this frequent association, the caregiver’s presence, attention, facial expressions, eye contact, touch, speech, and overall interaction are established from the beginning as powerful secondary reinforcers. Caregivers’ contingent attention and responsiveness to the needs and behaviors of their infants are predictive of the infant’s physical, social, intellectual, and emotional development as well as their eventual language development (Dunham, Dunham, Hurshman, & Alexander, 1989; TamisLamonda, Bornstein, & Baumwell, 2001). Any behavior on the infant’s part that evokes one or more of those social response elements from a caregiver–a touch, speech sounds, eye gaze, or a smile –in response will be effectively reinforced. This observation–the potency of the caregiver’s natural behavior to serve as a secondary reinforcer as a result of this convergence–is perhaps most crucial to understanding the dynamics of early learning so essential to interpreting and extrapolating Skinner’s Verbal Behavior to early language learning. As most would agree, it has been documented that infants are in turn responsive to caregivers’ presence, interaction, and attention in many domains of learning (Kuhl, 2004). Natural consequences. Most caregivers are naturally responsive to infants’ noncry vocalizations. In turn, infants appear to learn that their caregivers do respond and come to have expectations that they will respond contingently. This reciprocity and infants’ expectation connecting infants’ vocalizations and caregivers’ contingent responses suggests the reinforcing nature of these interactions (Goldstein, Schwade, & Bornstein, 2009). It has been demonstrated that infants’ vocalizations can be influenced by social reinforcement in controlled experimental studies (Rheingold, Gewirtz, & Ross, 1959; Routh, 1969; Todd & Palmer, 1968; Wahler, 1969; Weisberg, 1963). Furthermore, it has been shown that the frequency of infant vocalizations varies depending upon the nature of engagement with their caregivers (Keller & Scholmerich, 1987). At least one experimental study has demonstrated that infants’ can be conditioned to produce different responses based on differential social reinforcement (Routh, 1969). It should be noted that caregivers do not need to be conscious of providing reinforcement for these communicative behaviors; it occurs merely as the result of the natural interactions with their children. Infant behaviors that are attended to and effectively responded to by the caregiver are naturally reinf orced by the immediacy and relevance of the caregiver’s response. This is the essence of natural consequences, a critical concept in Skinner’s analysis that has been missed or misconstrued in many attempts to review, critique, or interpret Verbal Behavior (1957). Selective reinforcement. Another closely related concept, selective reinforcement, has been misinterpreted by some as well. A number of sources (Berko Gleason, 2005; Owens, 2005; Hulit, 2006) attempting to describe Skinner’s model in the context of language learning, have portrayed selective 118 SLP- ABA Volume 5, Issue No. 2 reinforcement as a conscious, even conscientious, process painstakingly applied by caregivers. Again, this interpretation seems to be related to Chomsky’s review of Verbal Behavior in which he contended that there is no evidence that caregivers use “slow and careful” reinforcement applied with “meticulous care” to teach language to their child (Chomsky, 1959, pp. 39,42,43). However, this is simply another one of Chomsky’s “straw men” in that Skinner never indicated such requirements. More than 30 years after he published his Verbal Behavior, Skinner (1988, p. 486) wrote that: Chomsky and others often imply that I think that verbal behavior must be taught, that explicit contingencies must be arranged. Of course, I do not, as Verbal Behavior makes it clear. Children learn to speak in wholly noninstructional verbal communities. But the contingencies of reinforcement are still there, even though they may be harder to identify. (p. 486) Perhaps some confusion stems from the distinction between reinforcement as part of an experiment and as it occurs in the natural environment. In Routh’s (1969) study, different classes of infant vocal responses–consonant-like sounds, vowel-like sounds, and all vocalizations–were chosen by the study design for the purpose of determining if infants’ vocal behaviors were responsive to differential reinforcement. The specific vocal behavior that was reinforced in each infant in fact increased selectively. This was a useful and purposeful distinction; the isolated increase in the specified vocal behavior being reinforced demonstrated the effects of selective reinforcement. However, in this demonstration the vocal behaviors were chosen by the investigator as part of the experimental design. Selective reinforcement under normal circumstances is the natural result that follows when one response survives and is strengthened because it is more effective than another. In the natural environment’s differential reinforcement–intentional or unintentio nal–is contingent on the value of a response and it “selects” the response by strengthening its future probability. Selective reinforcement is analogous to the natural selection that perpetuates useful variations in traits within a species. As Skinner pointed out in About Behaviorism, in the same way that “accidental traits, arising from mutations, are selected by their contribution to survival, so accidental variations in behavior are selected by their reinforcing consequences” (1974, p. 114). When reinforcement is more likely to follow an effective response, it selectively strengthens that response over less effective responses. The caregiver does not need to be conscious of “selecting” one response over another; children’s responses are selectively reinforced by virtue of communicating more effectively and evoking favorable outcomes. Caregivers do not wake up each morning planning which behaviors they will reinforce and what schedule of reinforcement they will use that day; they wake up hoping to help their offspring thrive, learn, and be happy. Both natural consequences and selective reinforcement are central aspects of the subtle consequences that determine children’s communication behaviors, including those that will become integrated into the lasting verbal behaviors that comprise language. Summary. The basic elements of Skinner’s functional analysis of verbal behavior (1957) include the stimuli–external and internal–that set the stage for verbal behavior and the consequences that affect its reoccurrence. For the young infant, the environment is generally composed of those stimuli that either emanate from the caregiver–speech, touch, eye contact, facial expression, as so on–or occur as a result of actions by the caregiver–change in position, proximity to other stimuli, presentation of food, and so on. The infant’s frequent, consistent, and contingent interactions with the caregiver while having primary survival needs addressed automatically keys in the caregiver’s attention as a powerful secondary reinforcer that occurs naturally and is capable of selectively strengthening various infant responses. A Functional Analysis of Verbal Behavior: Correlates in Early Language Learning Skinner (1957) developed his model based on verbal behavior as a conspicuous and ubiquitous example of complex social behavior. He defined verbal behavior as a social behavior that is “reinforced through the mediation of other persons” (p. 2)–an especially fitting description of early language learning. 119 SLP- ABA Volume 5, Issue No. 2 His interlocking verbal paradigm captured the reciprocal nature of social interaction that is intrinsic to human verbal behavior. Applying this framework, he then illustrated the types of verbal behaviors–verbal operants–that occur in episodes or exchanges based on their circumstances, each speaker’s behavior, and the consequences that follow. Different contingent relationships serve to functionally define different primary verbal operants. Each category of verbal operant represents a set of verbal behaviors that tend to occur under similar setting events and are reinforced in characteristic ways. Beyond the primary verbal operants, autoclitic behaviors represent the essence of “grammar” and more in Skinner’s analysis (see Hegde in this issue). Along with some basic concepts central to the analysis, several verbal operants and their relevance to early language learning will be described. Correlated traditional concepts and terminology will be integrated into the discussion of each. Concepts Central to a Functional Analysis Unit of Analysis Description: In analyzing verbal behavior, especially in the context of early language learning, it is important to note that Skinner’s unit of analysis–the verbal operant–was functional, not structural. It was more important for him to consider the settings and the consequences of verbal behavior than its formal structural characteristics (i.e., noun, noun phrase, declarative). With infants, of course, the initial level of behavior is more vocal than verbal. Vocal behaviors that evoke caregiver attention and interaction evolve from cooing, babbling, and jargon that increasingly contain adult-like speech elements, including syllable patterns and intonational contours, and evoke verbal responses from caregivers (i.e., motherese). As a result, infants’ vocal behaviors gradually transition toward verbal behaviors (i.e., the first word). With children, the nature of the verbal operant will evolve over time. In addition, the size of the functional verbal operant will expand over time. As the child becomes capable of coordinating longer motor sequences in his or her speech, his or her utterances can orchestrate more relations and address social agendas more deftly as they expand, for example, from mere grunts and gestures to “Cookie” to “More cookie” to “Two big cookies” all the way to “I can tell from how they smell that you make the best chocolate chip cookies!” Correlates in Early Language Learning: Traditional literature includes few, if any, close correlates to Skinner’s functional unit of analysis. Dore’s “Primitive Speech Acts” (Dore, 1974) and “Conversational Speech Acts” (Dore, 1986) perhaps come closest due to their pragmatic basis. Given the preceding example of how a “functional unit” might evolve from primitive grunts and gestures to quite sophisticated and diplomatic indirect requests, some might be led to equate Skinner’s unit of analysis with the pragmatic concept of “purposes,” such as described in Speech Acts theory (Searle, 1969). It is important to remain aware that Skinner used the term “function” to refer to the causal explanations of verbal behaviors, as when noting that a certain response seems to be causally related to certain circumstances and a past history of reinforcement. Invoking the mentalistic concept of “purpose” as is done in pragmatic analyses makes that model different from Skinner’s. Interlocking Verbal Episodes Description: A vital aspect of Skinner’s model was casting the functional analysis in terms of interlocking verbal episodes intended to capture the “back and forth” reciprocal nature of verbal behavior between a speaker and listener whose roles frequently interchange throughout the interaction. In most cases, there are at least two participants in a verbal exchange. Each alternately serves as the speaker and the listener. As the exchange progresses, the verbal behavior of the first serves as a discriminative stimulus (SD ) and possibly a reinforcer (Sr) for the second. In turn, the second individual may respond verbally to the verbal SD produced by the first person. The verbal behavior of the second person may 120 SLP- ABA Volume 5, Issue No. 2 serve to reinforce the first person and serve as a verbal SD that evokes a subsequent response from the first person and so on until the series of verbal exchanges (i.e., the conversation) terminates. In early interactions, episodes are frequently prompted by the caregiver with eye contact, physical contact, facial expressions, or speech (“motherese”). Recent studies have continued to demonstrate the significant role that the caregiver’s presence and interaction can play in influencing infant attention, vocalization, reciprocity, and even enhancing their discrimination of the speech around them (Gartstein, Crawford, & Robertson, 2008; Goldstein, Schwade, & Bornstein, 2009; Keller & Scholmerich, 1987; Kuhl, Tsao, & Liu, 2003). Mothers adjust their behavior to their children’s and children as young as 9 and 13 months make active adjustments to their caregiver behaviors based on their developmental needs to evoke more meaningful responses from the mother (Tamis-Lamonda, Bornstein, & Baumwell, 2001). These observations suggest that even prior to the first birthday interactions that fit the verbal interlocking paradigm have already become established to enhance language growth “in the context of responsive social exchanges between caregivers and children” (Tamis-Lamonda, Bornstein, & Baumwell, 2001, p. 763). Correlates in Early Language Learning: For a number of years, the literature has described the occurrence of phenomena that illustrate the concept of the verbal interlocking paradigm. Beginning with proto-conversations in caregiver-infant feeding interactions (Bateson, 1971; Locke, 1993) and the earliest forms of conversational interaction (Dore, 1986) , caregiver-child discourse has been recognized as a rich source of teaching and learning about language. These phenomena represent important interactions that could be captured as interlocking verbal episodes and analyzed for the social and verbal transactions that occur through them. A cumulative history across ongoing exchanges between caregivers and children would probably allow an analysis of the diverse set of subtle teaching tools used by caregivers that may not even be apparent to the caregivers. Hart and Risley (1999) collected monthly recordings for 30 months of the interactions between 42 children and their families. In their analysis they discovered surprisingly rich opportunities in families for most children to be exposed to language models. They found that an average of 700-800 utterances per hour was produced by people within hearing distance of a child. The average of utterances directed by the parent to the child was 300-400 per hour. The parents’ language to others contained richer vocabulary and longer clauses and used declarative statements 60% of the time. In contrast, the parents used more questions and directives with their children, averaging 83 questions per hour. Hart and Risley analyzed much of their data in terms of “episodes,” defined as occasions in which families and children directed social behavior toward each other terminated with 5-second boundaries of no social behavior. An average of 96 interactional episodes was recorded each hour and, interestingly, more than half of the episodes were initiated by the children. However, social responsiveness remained constant; in episodes containing utterances by both parents and children, the ratio of utterances was 50:50 throughout the 2 year period of learning to talk. These findings document extensive reciprocal and symmetrical interactions that correlate to Skinner’s interlocking verbal episodes and occur frequently throughout a child’s experience with adults, forming an important foundation of early language learning. The Influence of Stimulus Control Description: When a response has been reinforced in the presence of a stimulus, the stimulus potentially gains the ability to influence or control the likelihood of that response occurring in the future. The very first productions of “mama” or “dada” may or may not be verbal operants (“intentional” or “meaningful”), but they are nonetheless fortuitous. These two syllable pairs occur frequently in the early sound repertoire of children babbling in most every human language, possibly due to their underlying connection to oral-motor actions involved in feeding. The younger the infant when these syllable pairs are first heard, the less likely they are the true “first words.” Nonetheless, at any age, mothers and fathers respond differentially to those two productions. When those syllables occur in their absence, it is not 121 SLP- ABA Volume 5, Issue No. 2 likely that others respond quite as enthusiastically, especially in the early months. Over time, however, after being reinforced by the relevant parent, those syllables are produced more frequently and differentially depending on who is immediately present. Once the child produces “mama” and “dada” reliably in their presence, mother and father have become the controlling stimuli for those responses. Stimulus discrimination and stimulus generalization. Stimulus discrimination occurs when a restricted set of stimuli exclusively controls or influences a response, apparently due to a relatively narrow set of controlling or “defining” features. Conversely, stimulus generalization occurs when different stimuli that are similar in some defining manner become controlling stimuli for a response. Initially, for a young child “mama” carries the sense that there is only this one person in his or her world who deserves this moniker. That response initially exhibits strong stimulus discrimination. In most cases, there is one adult female present to respond to and reinforce the early random forms of “mama.” However, at some point, perhaps following more exposure to additional adult females, stimulus generalization occurs and soon every adult female is called “mama” or “mommy.” Eventually, through a counterbalancing process of generalization and discrimination, the child learns that only certain adult females qualify as “mommies” and, at least implicitly, the child comes to reserve the “capitalized” version, “Mommy,” for his or her own. He or she learns that there is a broader category of “mommies” and a specific instance of “Mommy.” Correlates in Early Language Learning: Children’s vocabulary learning in language development has always been of interest to researchers. The various responses children produce as they attempt to label and categorize people, objects, and events around them gives us that special sense of having a “window into their minds.” In traditional literature it has long been acknowledged that children only gradually learn to use words according to the adult conventions or boundaries. In the process, children have been described as producing “overextensions”–extending the use of a word beyond its conventional meaning (Bloom, 1973). A familiar example used to illustrate overextensions is children calling every creature with four legs, fur, and a tail, a “doggy.” With experience and corrective feedback, children’s overextensions are remediated by their verbal community. However, their occurrence provides a straightforward illustration of the behavioral process of stimulus generalization, albeit over-generalization with respect to the conventional meanings. Theories on children’s cognitive processes as they develop their concepts and word meanings have focused on hypothetical mental processes that may underlie these phenomena. The prevailing notion is that the child is hypothesis testing in attempts to develop the meaning of a word (Brown, 1958). Some theories have emphasized the child’s apparent attention to perceptual features (Clark, 1973) and others have stressed that children base their conceptual meanings for words on the central or core function of an object (Nelson K. , 1974). In a functional analysis, it may turn out that these aspects are operative as different levels of controlling stimuli across individual children, but behaviorally a child will only demonstrate conceptual behavior if his or her response generalizes within a group of stimuli that are similar in some defining way and discriminates across groups of stimuli that differ in defining ways. Contingency Shaped Behavior Description: Contingency shaped behavior consists of behaviors that evolve through a gradual process of differential reinforcement. Very few, if any, voluntary behaviors, especially complex behaviors, are present at birth. As the infant gradually gains voluntary control over various movements and responses, the consequences that follow–some positive and some negative–cause behaviors to gradually emerge, evolve, and refine. To the extent that caregivers are responsive to infant behaviors, it appears that the contingent nature of their responses is important to the infant. Goldstein, Schwade, and Bornstein (2009) found that 5-month-old infants had learned that an adult had been responding contingently to their vocalizations. After a period of responding contingently to infants’ vocalizations, when the adults assumed a still face, 122 SLP- ABA Volume 5, Issue No. 2 infants exhibited extinction bursts in which their smiling decreased and vocalizations increased. Additionally, 9-month-old infants, when presented with vocal production models by their mothers contingent on their own babbling, modified their babbling and included the mother’s phonological patterns in their babbling (Goldstein & Schwade, 20008). Skinner (1957) emphasized the importance of response contingent behavior between speaker that maintains responding and shapes responses during the overall process of learning language. In addition, to the extent that it provides differential reinforcement or corrective feedback it would also shape the outcome of the process by strengthening response forms that evolve toward the conventions of the language. Tamis-LeMonda, Borstein, and Bauwell (2001) found that maternal responsiveness to infants’ play and vocalizations at 9 months and 13 months were predictive of the infants’ achievement of several language milestones. Correlates in Early Language Learning: This concept has special relevance to Skinner’s analysis of verbal behavior. Following Chomsky’s model, Brown (1973) , among many others, had asserted that the child was acquiring the rules of grammar by extracting the regularities or patterns in the language he or she was exposed to. The regularities or patterns in the child’s language presumably revealed the internalized rules of grammar that governed the child’s language production. The distinction between “rule-governed behavior” and “contingency-shaped behavior” became a central issue that crystallized a key difference between Chomsky’s theory and Skinner’s analysis. The former placed the controlling mechanism in the child’s mind (the LAD) and the system of rules being extracted from exposure to the language. The latter placed the controlling mechanism in the history of reinforcement that incrementally shapes behaviors toward conventionally accepted and consistent patterns of verbal behavior. Such consistent patterns may be described as evidence of “rules.” However, the behavioral evidence for such “rules” contradicts what most would expect. In characterizing rule-governed behavior, one would expect a more rapid and complete change in behavior that quite promptly complies with the newly learned rule. However, in the case of early language learning, most behaviors evolve gradually (Brown, 1973). In About Behaviorism, Skinner wrote, “Certainly for thousands of years people spoke grammatically without knowing that there were rules of grammar. Grammatical behavior was shaped, then as now, by the reinforcing practices of verbal communities in which some behaviors were more effective than others…” (1974, pp. 127-128). In fact, in a seldom quoted section in his landmark book about children’s mastery of grammatical morphemes, Brown (1973) very clearly described this shaping process in describing the subjects’ “unaccountable regressions and unexplained abrupt advances,” stating that the learning involved must be conceived as gradual change in a set of probabilities rather than as the sudden acquisition of quite general rules. If our conception is correct, it means that the learning of the … 14 grammatical morphemes is more like habit formation and operant conditioning than anyone has supposed. Skinner’s definition of operant strength in terms of response probability is surprisingly apt. (p. 388) Still, in his overall conclusions, Brown (1973) determined that there was no evidence in his data of “selective pressures” being exerted through adult models or through direct reinforcement by adults. Moerk (1992) obtained Brown’s entire data set and performed a different analysis on it. Brown had used frequency counts of parent use of the morphemes in question and found that neither parental models for, nor parental expansions of, a child’s utterance correlated with the children’s mastery for that morpheme. In contrast, Moerk used a microanalysis of the learning process present in caregiver-child interactions across adjacent time periods. This approach revealed the extent to which the parent’s modeling, corrective feedback (reinforcement), and massing (repeated, intense modeling of a structure) were at work in shaping the child’s subsequent productions. Brown’s simplified operational definition (1973) of models, 123 SLP- ABA Volume 5, Issue No. 2 reinforcement, and feedback had essentially eliminated recognizing their roles in his own data (Moerk, 1992). Verbal Operants in Developing Language Skinner designated the basic elements of verbal behavior as primary verbal operants. As the building blocks in his functional analysis, each primary verbal operant is based on the contingency represented between the setting event that “sets the stage” for a characteristic type of verbal behavior due to the reinforcement that has followed that type of verbal behavior. These primary verbal operants become the elements or fragments that, once reinforced, are available to be rearranged through the speaker’s secondary verbal behavior into more complex responses. Consistent arrangements of these primary verbal operants evolve in ways that, by convention, reflect the different relationships among them and other variables inf luencing the speaker. The following is a brief summary of each primary verbal operant. There is certainly more to understanding each one than can be included here. (Again, the reader is referred to Hegde, in this issue, for a more complete review and discussion of Skinner’s Verbal Behavior.) Mands Description: A mand is a verbal operant in which the verbal behavior specifies its reinforcement. It occurs in response to a deprivation state or an aversive state. In general terms, the speaker’s verbal behavior tells the listener how to reinforce the speaker by addressing a deprivation state (hunger, thirst, social contact, etc.) or by terminating an aversive state (cold, wet, pain, lack of information, etc.). Correlates in Early Language Learning: For infants, the earliest cry behaviors, although not conscious or intentional, probably represent the first demands placed on the environment around them (Formby, 1967). Although the infant’s cry cannot “specify” the reinforcement, there are not too many needs to choose from–food, dry diaper, sleep, or company–and caregivers typically address the specific need either by recognizing the particular cry through past experience or through a process of elimination. Obviously, for the infant, this responsive and contingent behavior is crucial to implanting the sense that the world responds in some way when he or she behaves and help establish the earliest mand. With motor development, mands expand to include reaching and pointing and as new verbal behaviors are learned, they come to include additional specifics with more socially appropriate and effective forms–“I’d like the donut with white icing and sprinkles, please.” The literature in early development of pragmatic abilities is replete with examples of early communicatio n skills that essentially illustrate mands. The most straightforward example is Primitive Speech Acts (PSAs) (Dore, 1974). Of the 10 types of PSAs included in the classification of pragmatic behaviors, four of them are essentially mands–Calling, Protesting, Requesting Answer, and Requesting Action. Echoics Description. The obvious reference for the term echoic is the word “echo.” An echoic is verbal behavior that reproduces the acoustic properties of another’s verbal behavior. Imitation is the traditional sense of echoics, but traditionally carries with it a sense of intention. We imitate when asked or for some purpose, where there are aspects of others’ verbal behavior that are sometimes reproduced without any awareness on the part of the speaker. After some time in a different geographic region, we take on the accent or the expressions of that region without necessarily being conscious of the change in our verbal behavior. Correlates in Early Language Learning: Infants may exhibit the earliest echoics in the nature of their babbling. Although there is a measure of controversy surrounding this phenomenon, it cannot be denied that infants’ babbling gradually sounds increasingly like the native language to which they are 124 SLP- ABA Volume 5, Issue No. 2 exposed. One theory (Mowrer, 1952) that actually predated Verbal Behavior, described the process as one in which speech sounds produced by the infant that more closely resemble the caregivers’ sounds that have been long associated with feeding sessions were automatically self-reinforcing. This process causes those sounds that are more natural to the verbal community to gradually become more prominent in the infant’s babbling while those that are not, and as a result are not self-reinforced, decrease in frequency. The hypothetical result of Mowrer’s autism theory–the gradual evolution of babbling toward the sounds of the parents’ language–has been documented even at the level of echoing both the phonemes and intonational contours of another speaker (deBoysson-Bardies, Sagart, & Durand, 1984). Beyond the first year, echoics would appear to be most useful for children in learning new vocabulary when caregivers and teachers prompt them to repeat a new word. Children appear to imitate vocabulary terms under a variety of circumstances. Leonard, Schwartz, Folger, Newhoff, and Wilcox (1979) found that children’s imitations of lexical items were more likely when the term and its referent were novel and when the referent was informative in the present context. Keenan (1974) suggested that at times children imitate their partner’s utterance when it appears that they are unable to add significant information to the exchange–probably not unlike the ill-prepared student who simply repeats the instructor’s unexpected question. In addition, some have suggested that in the process of selective imitation, producing partial echoics might provide children with the opportunity to include words and phrases from the language models around them as their repertoire of verbal behavior expands. The correspondence between the models being echoed and the attempted communication might be reinforced differentially. Echoing or including a relevant word, word ending, or phrase might result in an utterance that is reinforced through a better outcome. Folger and Chapman (1978) found that children at the one- and two-word stage were more likely to imitate an adult’s utterance if it was an expansion of their own preceding utterance. Interestingly, because the adult’s expansion was typically partially based on the child’s utterance, it would constitute a partial echoic, and the children were more inclined to imitate these than an adult’s exact repetition of their utterance. Farrar (1992), like several others (Moerk, 1992; Nelson K. E., 1977) found that 2-year-old children were two to three times more likely to imitate the correct grammatical feature in response to corrective recasts which replace incorrect or missing grammatical features, than any other maternal responses. Again, in all these examples, the children’s selective imitation through reproducing a partial echoic appeared to be an important learning tool used to shape their production of grammatically progressive forms. With some fear of belaboring the point, it is important to ask why these instances of echoic behaviors can be considered as learning tools as opposed to simply moments of meaningless, nonprogressive imitation. As indicated throughout this paper, the connection between the caregiver’s attention and continued interactions were established as powerful secondary reinforcers from the beginning. To the extent that a child approximates the caregiver’s (and through generalization, all adults’) recast or expansion of his or her ungrammatical response, the child’s echoic behaviors are automatically self-reinforced (see Hegde, in this issue, for more on echoics and language learning). Tacts Description: Verbal behaviors that allow listeners to be in “contact” with the speaker’s environment are called tacts in Skinner’s model. Tacts are essentially verbal behaviors that “name” or “describe” the elements of the environment. Because tacts, to be reinforced, must exhibit conventional correspondence to how others in the verbal community would talk about the same circumstances, they allow sharing with listeners the objects, persons, events, and relationships that originally evoked the speaker’s verbal behavior. We share our experiences with others through tacting. 125 SLP- ABA Volume 5, Issue No. 2 Tacting takes its first form in the proverbial first words, when children begin to consistently respond to their caregiver’s presence with “mama” or “dada” or name their favorite toy. Of course, these tacts evoke much attention and celebration, but otherwise caregivers continue to attend and respond to most tacts to encourage children to maintain and expand descriptions of their experiences well into the future, especially those that are out of the caregiver’s view. For the child, the causation for tacting is different than for manding. The two verbal operants might be functionally confused, for example when the toddler’s tact is misinterpreted as a mand. Manding is caused by a state of motivation and will be reinforced by receipt of the specified reinforcer–say, when a child truly asks for more ice cream and then eats it. If the words “ice cream” were not due to an actual desire for ice cream, and instead were simply tacts noting its presence to evoke a comment from the caregiver, any ice cream that is provided may be used for finger painting or end up on the floor. Correlates in Early Language Learning: Children’s first words are a source of joy for caregivers and a source of fascination for researchers. Beyond the traditional first word occurring on the first birthday, researchers have been intrigued by the grammatical composition of first words and the first 50 words. At least from the superficial perspective, there has been a predominance of nouns reported in both cases (Nelson K. , 1973). This “noun bias”–naming objects, people, animals, and so forth–has been found in maternal speech to one-year-olds (Goldfield, 1993). Some (e.g., Gentner, 1982) have taken this as evidence of an innate predisposition toward learning nouns, in which children learning any human language should be predisposed to learning nouns. Testing this premise, however, others (e.g., Tardif, Liang, Zhang, Fletcher, & Kaciroti, 2008) have found that there are not only cross-linguistic differences but evidence of strong influence from parental input. Extended Tacts Description. Skinner noted that “stimulus control is by no means precise” (1957, p. 91). When a response is reinforced in the presence of an object or event, there is actually a variety of features that accompany the primary stimulus. When another stimulus appears that shares at least one of those features, the original response may occur as an extended tact–it is extended to the new stimulus based on stimulus generalization. Skinner described a number of extended tacts that illuminate a variety of most interesting verbal behaviors; these will not be addressed here, but are nonetheless fascinating. (See Hegde, in this issue, for a discussion of generalized tacts.) Correlates in Early Language Learning: Perhaps the most obvious manifestation of extended tacts in our observations of children learning language is what has been widely called “overextensions.” The classic examples include the young child who having become familiar with the family pet–the one that has four legs, fur, a tail, and barks–proceeds to call everything with four legs and fur a “doggy.” These and the conceptual behavior they illustrate were discussed previously in relation to the influence of stimulus control. Other examples of extended tacts include the development of figurative language. Metaphors, similes, idioms and proverbs are examples of figurative language that are essentially based on stimulus generalization. In most such expressions, a relationship shared by two sets of stimuli is expressed through an analogy as in the idiomatic expression, “Don’t let the cat out of the bag,” which likens letting a feline escape to giving out a secret. Due to their abstract nature, these expressions are less likely to be understood by younger children. An individual expression may be learned by rote and used in very limited context until the stimulus generalizations that underlie such figurative expressions become well established. The concept of metaphoric transparency has been used to describe the degree to which the literal meaning and figurative meaning are similar (Gibbs, 1987). Because, in contrast to the previous example, the literal meaning of the expression, “Don’t beat around the bush” is less similar to its figurative meaning, this latter idiom would be said to exhibit less metaphoric transparency. Perhaps it 126 SLP- ABA Volume 5, Issue No. 2 would be expeditious to not “beat around the bush” and simply recognize that these two sets of stimuli involved using and understanding this idiom have less in common, which behaviorally makes them less likely to evoke or support the stimulus generalization necessary to understand them. Autoclitics: Secondary Verbal Behaviors Description: Perhaps the most subtle and interesting element in Skinner’s (1957) functional analysis of verbal behavior is autoclitic behavior. Skinner characterized autoclitic behavior as a secondary level of verbal behavior in which the speaker’s behavior comments on the relationships among the primary verbal behaviors by inserting certain words or word endings or through rearranging their order. Skinner classified these secondary behaviors as autoclitic words (“is”, “was,” “but,” “and,” etc.), autoclitic tags (“-ed,” “-ing,” “-s,” “-ion,” etc.), and autoclitic orders, (such as those used in English for statements, questions, imperatives, etc.). Autoclitic behavior is most essentially Skinner’s way of addressing the traditional concepts of syntax and grammar. Traditionally, syntax and grammar are comprised of the mental rules that dictate the order of words and word endings. In contrast, Skinner conceived of these words, word endings and orders as being reinforced and shaped to conform to the verbal community. Due to the established practice in a verbal community, a certain word order is more effective in sharpening the listener responses than an order that is not part of that practice; the proverbial headline “Man Bites Dog” is eye-catching not because of the three words involved, but because the order in which they have been arranged corresponds to a relationship that occurs infrequently and evokes effective responses as a consequence. Correlates in Early Language Learning: An important correlate in the traditional literature was again provided by Brown (1973) in his landmark book, A First Language. Brown noted that as the children in his study began producing multi-word utterances, they began to express certain semantic roles and relationships by relying on consistent word orders. This appeared to be in lieu of the grammatical inflections that had not yet emerged. For example, without the possessive inflection /’s/ available, the children appeared to rely on a set word order to “express possession,” as the traditional formulation goes. Any number of different word pairs placed in similar order could achieve the same result (e.g., mommy sock, baby shoe, daddy chair). Of course, without the possessive inflection, they still had to rely on adults to interpret the word orders based on the situational context. Brown coined the term “case frames” for these consistent word orders (1973, p. 135). This is an interesting correlate to Skinner’s (1957) concept of autoclitic frames (p. 361) and syntactic frame s (p. 405) which refer to similar consistent word orders used to comment on relationships among the primary verbal behaviors. Another important correlate in the literature that illustrates the relevance of Skinner’s model appeared not long after Verbal Behavior (1957) was published. Berko (1958) published what became a landmark study illustrating a phenomenon in child language called overregularization. It has been observed that young children initially learn to correctly produce irregular past tense verbs (e.g., ran, sat, ate) and irregular plural nouns (e.g., men, women, children). However, at the approximate time that they begin to produce the regular forms using the grammatical inflections /-ed/ and /-s/, they appear to “unlearn” the irregular forms and produce overregularized forms such as eated, sitted, runned. This phenomenon has been explained through a variety of mentalistic models, including single mechanism, connectionist, or network mechanisms (Maslen, Theakston, Lieven, & Tomasello, 2004). In contrast, Skinner’s model explains this phenomenon in a more objective and scientifically elegant manner relying on the behavioral principles of stimulus generalization and response induction. For example, in the case of past tense the controlling stimulus for both regular and irregular forms is the past time frame for an event. The irregular verb forms learned earlier by children relate to common everyday events–sitsat, eat-ate, run-ran, and so forth. When the child begins to learn the regular past tense inflection, it will naturally occur in response to events that also occur in the past time frame. Because this is the controlling 127 SLP- ABA Volume 5, Issue No. 2 stimulus common to both, stimulus generalization occurs and response induction causes the regular form to generalize to all occurrences of past tense, causing the child to produce sitted, eated, runned, and so on. Conclusion The ultimate test of any analysis is whether it offers a better and more parsimonious explanation and whether if finds application. An important dispositio n in the conduct of science is that it is better to go without an explanation than to settle for an inadequate one (Bachrach, 1972; Hegde, 2003). Skinner’s analysis of verbal behavior offers a parsimonious explanation based on experimentally manipulable empirical relations as against unobservable mentalistic or cognitive structures (see Schilnger in the current issue). When so many had settled prematurely on an inadequate explanation (e.g., the innate mechanisms, grammatical universals, the LAD and the LAS), we can now see the debt of gratitude owed to so many who were committed to arriving at an empirically based understanding of language learning. Although more research is needed, applied research based on Skinner’s Verbal Behavior has increased to a significant extent, as evidenced in publications in such journals as The Analysis of Verbal Behavior, The Behavior Analyst, Journal of Applied Behavior Analysis, and several other national and international journals. Professionals in a number of fields have used the tools of change described by Skinner–possibly in many cases without recognizing it. Much of the evidenced-based treatment procedures in speech-language pathology are behavioral procedures that are based on Skinner’s operant conditioning, currently generally described as applied behavioral analysis (Hegde, 1998). That this evidence has such good fit is vindicating of the insights provided by Skinner’s analysis. It is now time for speech-language pathologists to see the inconsistency of holding up the LAD or other innate mechanisms as the basis for language learning while applying behavioral principles in actually changing language behaviors. That most clinicians manipulate the environmental variables, including their own models, contexts, stimuli, and reinforcement in their everyday clinical practice is not only vindicating of Skinner’s analysis, but compelling of clinicians to understand and adopt that analysis. References Bachrach, A. J. (1972). Psychological research: In introduction. (3rd ed.). New York, NY: Random House. Bateson, M. (1971). The interpersonal context of infant vocalizations. Quarterly Progress Report, Research Laboratory of Electronics , 100, 170-176. Berko Gleason, J. (2005). The development of language (6th ed.). Boston: Allyn & Bacon. Berko, J. (1958). The child's learning of English morphology. Word , 14, 150-177. Bloom, L. (1973). One word at a time: The use of single-word utterances before syntax. The Hague: Mouton. Bloom, L., & Lahey, M. (1978). Language development and language disorders. New York, NY: John Wiley & Sons. Brown, R. (1973). A first language: The early stages. Cambridge, MA: Harvard University Press. Brown, R. (1958). Words and things. New York, NY: Free Press. Chomsky, N. (1965). Aspects of the theory of syntax. Cambridge, MA: M.I.T. Press. 128 SLP- ABA Volume 5, Issue No. 2 Chomsky, N. (1959). Review of Skinner's Verbal behavior. Language , 26-58. Chomsky, N. (1957). Syntactic structures. The Hague: Mouton. Clark, E. V. (1973). What's in a word? On the child's acquisition of semantics in his first language. In T. E. Moore (Ed.), Cognitive development and the acquisition of language. (pp. 65-110). New York, NY: Academic Press. deBoysson-Bardies, B., Sagart, L., & Durand, C. (1984). Discernible differences in the babbling of infants according to target language. 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(1982). Why nouns are learned before verbs: Linguistic relativity versus natural partitioning. In S. Kuczaj (Ed.), Language development: Language, thought, and culture. (Vol. 2, pp. 301333). Hillsdale, NJ: Erlbaum. Gibbs, R. W. (1987). Linguistic factors in children's understanding of idioms. Journal of Child Language , 14, 569-586. Goldfield, B. (1993). Noun bias in maternal speech to one-year-olds. Journal of Child Language , 20, 8599. Goldstein, M. H., & Schwade, J. A. (20008). Social feedback to infants' babbling facilitates rapid phonological learning. Psychological Science , 19, 515-523. Goldstein, M. H., Schwade, J. A., & Bornstein, M. H. (2009). The value of vocalizing: Five-month-old infants associate their own noncry vocalizations with responses from caregivers. Child Development , 636-644. Hart, B., & Risley, T. R. (1999). The social world of children learning to talk. Baltimore, MD: Paul H. Brookes . 129 SLP- ABA Volume 5, Issue No. 2 Hegde, M. N. (2003). Clinical research in communication disorders: Principles and strategies. (3rd ed.). Autsin, TX, CA: Pro-Ed. Hegde, M. N. (1998). Treatment procedures in communicative disorders (3rd ed.). Austin, TX: Pro-Ed. Hulit, L. M. (2006). Born to talk: An introduction to speech and language develpment. Boston: Allyn & Bacon. Keller, H., & Scholmerich, A. (1987). Infant vocalizations and parental reactions during the first 4 months of life. Developmental Psychology , 62-67. Kennan, E. (1974). Conversational competence in children. Journal of Child Language , 1, 163-184. Kuhl, P. K. (2004). Early languge acquisition: Cracking the speech code. Nature , 5, 831-843. Kuhl, P. K., Tsao, F.-M., & Liu, H.-M. (2003). Foreign-language experience in infancy: effects of shortterm exposure and social interaction on phonetic learning. Proceedings of the National Academy of Sciences , 9096-9101. Leonard, L. B., Schwartz, R. G., Folger, M. K., Newhoff, M., & Wilcox, M. J. (1979). Children's imitations of lexical items. Child Development , 50, 19-27. Locke, J. L. (1993). The child's path to spoken language. Cambridge MA: Harvard University Press. MacCorquodale, K. (1970). On Chomsky's review of Skinner's Verbal Behavior. Journal of the Experimental Analysis of Behavior , 83-99. Maslen, R. J., Theakston, A. L., Lieven, E. V., & Tomasello, M. (2004). A dense corpus study of past tense and plural overregularization in English. Journal of Speech, Language, and Hearing Research , 47, 1319-1333. McLaughlin, S. (2006). Introduction to language development (2nd ed.). Clifton Park NY: Thomson Delmar Learning. Moerk, E. L. (1992). First language: Taught and learned. Baltimore, MD: Paul H. Brookes. Mowrer, O. H. (1952). Speech development in the young child: 1. The autism theory of speech development and some clinical appications. Journal of Speech and Hearing Disorders , 263-268. Nelson, K. (1974). Concept, word, and sentence: Interrelations in acquisition and development. Psychological Review , 81, 11-56. Nelson, K. E. (1977). Facilitating children's syntax acquisition. Developmental Psychology , 13, 101-107. Nelson, K. (1973). Structure and strategy in learning to talk. Monographs of the Society for Research in Child Development , 38, 1-136. Owens, R. E. (2005). Language development: An introduction (6th ed.). Boston: Allyn & Bacon. 130 SLP- ABA Volume 5, Issue No. 2 Rheingold, K. S., Gewirtz, J., & Ross, H. (1959). Social conditioning of vocalizations in the infant. Journal of Comparative and Physiological Psychology , 52, 68-73. Routh, D. K. (1969). Conditioning of vocal response differentiation in infants. Developmental Psychology, 1, 219-226. Searle, J. R. (1969). Speech acts. Cambridge, England: Cambridge University Press. Skinner, B. F. (1974). About behaviorism. New York: Alfred A. Knopf. Skinner, B. F. (1988). Skinner's reply to Catania. In A. C. Catania, & S. Harnad (Eds.), The selection of behavior: The operant behaviorism of B. F. Skinner: Comments and consequences (pp. 483-488). Cambridge, UK: Cambridge University Press. Skinner, B. F. (1938). The behavior of organisms. New York: Appleton. Skinner, B. F. (1957). Verbal behavior. New York: Appleton. Tamis-Lamonda, C. S., Bornstein, M. H., & Baumwell, L. (2001). Maternal responsiveness and children's achievement of language milestones. Child Development , 72, 748-767. Tardif, T., Liang, W., Zhang, Z., Fletcher, P., & Kaciroti, N. (2008). Baby's first 10 words. Developmental Psychology , 44, 929-938. Todd, G., & Palmer, B. (1968). Social reinforcement of infant babbling. Child Development , 39, 591596. Wahler, R. G. (1969). Infant social development: Some experimental analsyses of an infant-mother interaction during the first year of life. Journal of Experimental Child Psychology , 7, 101-113. Weisberg, P. (1963). Social and nonsocial conditioning of infant vocalization. Child Development , 39, 377-388. Winokur, S. (1976). A primer of verbal behavior. Englewood Cliffs, NJ: Prencice-Hall. Author Contact Information: Dr. Scott McLaughlin Speech-Language Pathology University of Central Oklahoma 100 N. University Drive Edmond, OK 73034 Email: [email protected] Phone: 405-974-5297 131 SLP- ABA Volume 5, Issue No. 2 The Bases for Language Repertoires: Functional Stimulus-Response Relations Raymond S. Weitzman Abstract This paper surveys the nature and types of stimulus-response relations and how those involved in operant conditioning are the ontogenetic bases for establishing, maintaining, and changing language behavior. It also examines and critiques two putative empirical claims under the poverty of the stimulus arguments that language behavior is stimulus free and that the linguistic input is limited and degenerate. It then discusses the relevance of operant stimulusresponse relations and principles in the treatment of speech-language disorders. Keywords: stimulus-response relations, reflex relations, respondent relations, operant relations, poverty of the stimulus arguments, speech-language interventions, treatment principles, treatment procedures ____________________________________________________________________ Introduction Speech-language pathologists (SLPs) and applied behavior analysts (ABAs) have much in common. They generally prefer evidence-based methodologies to inference-based methodologies. The evidence-based methodology of behavior analysis provides a causal basis for explaining behavior in terms of its functional relationship to environmental variables. While behavior analysts have certainly not discovered all the causes of human behavior, their experimental findings of lawful relations between environmental stimuli and behavior, how these relationships are established, and what kind of factors go into establishing and maintaining these relationships have given them great confidence in their endeavors and in their interpretations of how behavior repertoires are formed. This has resulted in the development of effective techniques in therapeutic situations and offers the prospect of future progress in applied areas. From the history of their field and from their experiences working with clients, SLPs and ABAs know that in many cases individuals with verbal behavioral disorders are amenable to improvement, if not a complete restoration to normal behavior. My purpose here is to discuss empirical issues that are the common concerns of SLPs and ABAs. Cognitive psychologists and most linguists have argued that language behavior cannot be learned “simply” through stimulusresponse relations (Chomsky, 1959). But what are S-R relations? How are such relations established? Are the objections of cognitivists and linguists to an explanation of language behavior in terms of S-R relations valid? In what follows I will try to answer these questions and in doing so demonstrate the relevance of special kinds of S-R relations—the operant S-R relations—to providing behavior interventions to those with speech-language problems. Functional Stimulus-Response Relations S-R relations can be interpreted in a variety of ways. In behavior analysis, what such a relation means is that behavior, in the form of an identifiable response (R), is controlled or has 132 SLP- ABA Volume 5, Issue No. 2 come to be controlled in some way by some identifiable event, condit ion, or situation in the environment. That environmental event, condition, or situation is called a stimulus (S). This relationship is a functional relationship in that the stimulus is defined in terms of the effect it has on behavior. The term stimulus can refer to (1) a specific instance of physical events, (2) combinations or complexes of events, (3) the absence of previously occurring events, (4) a relation among events, (5) specific physical properties of events, (6) classes of events defined by phys ical properties, and (7) classes of events defined functionally (Catania, 1998). After reading the previous list of what the term stimulus can refer to, the reader may be thinking that almost anything can be a stimulus. The most important thing to remember about an S-R relation is not what kinds of things can be stimuli or even responses, but the role stimuli play in affecting behavior. S-R relations must be determined empirically, i.e., based on observational and experimental findings about how environmental variables (the stimuli) and behavior (the responses) interact with each other. In the last sentence of the previous paragraph I deliberately used and emphasized the word “interact” with reference to stimuli and responses because often it is assumed that the temporal locus of a stimulus is antecedent to the response it affects. However, the temporal locus of a stimulus that affects behavior can also be a consequence of behavior itself, for behavior acts on the environment and in doing so often changes it (Cooper, et al, 2007, pp. 28-29). Altering the environment may then very well have an effect on future behavior. Just how future behavior might be affected as a result of a consequent stimulus change will be discussed in the following section on operant relations. Another thing to keep in mind about S-R relations is that in all likelihood these relationships do not involve single, unique events. This can be seen by the list of things that the term stimulus can refer to, given earlier. Although in a single observation or a single experiment, a specific S and a specific R are being considered, the relation between them may involve a number of different values of S and R. For example, the verbal stimuli “Sit down,” “Have a seat,” “Why don’t you make yourself comfortable ,” “Pull up a chair,” “Please be seated,” “Take a load off,” and so forth may all result in the “same” response of sitting down. Note also that the act of sitting down (R) is not without its variability. People sit down in many different ways, depending on what they sit down on, the kind of clothes they are wearing, their physical state, their emotional state, and such other factors.- But basically the relationship between the verbal stimuli of some speaker(s) and the physical response of some listener(s) is the same. Thus, for any given S-R relation, we are usually dealing with a class of stimuli and a class of responses. Each class may be given a particular verbal label. In this example, ‘sitting down’ is the label given to the response class and “mand to sit” might be given as the label for the stimulus class. It seems natural to suppose that if a stimulus class influences a response class in the same way, we would expect the members of the stimulus class to have some physical properties in common. This frequently happens, but it is not always the case. The members of the stimulus class given in the previous paragraph labeled “mand to sit” really have nothing physical in common except they are in the same receptive mode (auditory if spoken, and visual if written). Furthermore, they do not have very much in common structurally. Some belong to the same 133 SLP- ABA Volume 5, Issue No. 2 sentence class (Imperative) and a few share a lexical item (the indefinite article “a”), but not much else. Just what is the specific functional relationship between S and R is a matter of empirical circumstances. From a scientific point of view what is important is that these relationships are lawful, meaning that they are regular and predictable and established in the same empirical manner. Furthermore, if S and R are variables that can be manipulated by the experimenter, the possibility for altering the relationship arises. This alterability factor is of particular relevance for the speech-language and behavior analysis practitioner whose goal is to establish, change, or correct language behavior. Types of S-R Relations There are many ways of classifying S-R relations. In behavior analysis, however, S-R relations are classified according to whether the relations are reflexive , respondent, or operant. One of the key criteria for this classification has to do with whether the relationship is phylogentic or ontogenetic. Phylogenetic S-R relations are the products of the genetic selection that arise from the evolutionary history of a species. Phylogenetic S-R relations are often referred as being automatic , mechanical, and unlearned, because of their high degree of predictability. Ontogenetic S-R relations are those that are established by an organism’s interactions with its environment. They are said to be contingent or conditional, because they are more probabilistic and subject to the vagaries of changes in the environment. In other words, ontogenetic S-R relatio ns are learned. Reflex Relations Everyone is familiar with reflex relations or what are commonly called reflexes. Among these are the gag reflex, the knee-jerk reflex, the startle reflex, and the papillary light reflex. Reflexes involve involuntary responses to various environmental stimuli. In a reflex relation the stimulus is referred to as being unconditioned and is said to elicit the response. Human infants are known to have about a half-dozen so-called primitive reflexes that gradually disappear by the time they are one year of age. Reflexes are phylogenetically based S-R relations and therefore unlearned. They are a product of the evolutionary history of a species and universally part of a species’ behavioral repertoire. Using the jargon of computerese, reflexes are “hardwired.” Except for the developmental reflexes in human infants mentioned above, reflexes do not change much over the life span of an individual. Furthermore, they are usually unmodifiable. However, reflex relations may be temporarily weakened by repeated presentation of the unconditioned stimulus. Such a process is known as habituation. The reflex relation usually returns quickly after a fairly brief interval of time. Reflex relations can occur in chains. For example, the nursing process of newborn babies involves a chain of reflexes. First, touching an infant’s cheek elicits head turning in the direction of the tactile sensation (rooting reflex). If in the process of turning the infant’s mouth touches the surface of an object, this elicits sucking. If the object that infant comes in contact with is the mother’s nipple or the nipple of a bottle, milk will then enter the infant’s mouth. The sensation of 134 SLP- ABA Volume 5, Issue No. 2 milk in the mouth triggers swallowing. These chains are called reactive or reflex chains (Pierce & Cheney, 2008). Simple reflexes and reflex chains make up only a tiny part of the behavioral repertoire of a human being. It was once believed that all behavior could be explained in terms of reflexes, including consciousness (Sechenov, 1965). Reflexes were considered the elemental building blocks of all behavior. This mechanistic view, however, was overthrown by the later discoveries of respondent and, even more importantly, operant S-R relations. Reflexive vocalizations occur when an infant is sucking, swallowing, and burping. Fussing sounds and crying are also elicited by a wide variety of stimuli. Among these are deprivation of food or water, diaper rash, and other discomforting stimuli, including loud noises, noxious tastes or smells, etc. However, there is no empirical evidence that indicates that reflex relations play any role at all in the establishment or maintenance of language repertoires. It is important to note that although an involuntary response, whether vocal or non-vocal, is elicited by an unconditioned stimulus in a reflex relation, the same response or response class may also be evoked under other environmental conditions. Behaviors can and often do have multiple causes (Skinner, 1953, 1957). For example, an infant’s cry, as pointed out above, may be elicited under various kinds of physical deprivation or aversive stimuli, but may also come under the control of non-eliciting ontogenetic social and situational stimulus variables (Schlinger, 1995). Likewise, stimuli that may elicit a reflex response may also come to control behavior in a noneliciting way under other environmental conditions. For example, a flashing red light might elicit the orienting reflex response of head turning, but under other conditions may cause a driver to stop momentarily before driving on. How these non-eliciting stimulus-response functions are established will be discussed in the next two subsections. Respondent Relations “If reflexes were the only legacy of natural selection, an organism would be ill-equipped to survive in a changing environment.” (Donahoe & Palmer, 1994) As discussed in the previous subsection, reflex relations have been phylogenetically selected for and require the presence of a particular member of a stimulus class to elicit a particular member of a response class. But always contiguous with a particular eliciting stimulusevent are other kinds of environmental stimuli with other kinds of properties that are not necessarily in the same sensory mode. This opens up the possibility for these other stimulusevents to establish a new eliciting function with the reflex response. Ivan Pavlov (1849-1936) is given credit for discovering how such stimulus-response relations get established through a process known today as respondent conditioning (also called classical or Pavlovian conditioning). Respondent conditioning basically involves the contiguous pairing of the eliciting unconditioned stimulus with some other neutral stimulus called the conditioned stimulus . After several such pairings, the presence of the conditioned stimulus alone comes to elicit the reflex response, now called the conditioned response. Thus, a new S-R relation has been established through the original pairing of an unconditioned stimulus with a conditioned stimulus. 135 SLP- ABA Volume 5, Issue No. 2 The conditioned stimulus may be a property or a by-product of the unconditioned stimulus. For example, if a dog has been deprived of food for a sufficiently long period, the sight of food or the smell of food brings about salivation. However, the conditioned stimulus may be totally independent of the unconditioned stimulus, i.e., quite arbitrary. In some of Pavlov’s experiments with dogs (Pavlov, 1927), the conditioned stimulus was the sound of a bell, or a metronome, or the sound of the laboratory door being opened by the experimenter, or even Pavlov himself as he entered the laboratory to perform an experiment on one of his dogs. Pairing a conditioned stimulus with an unconditioned stimulus is referred to as firstorder respondent conditioning. It has been shown experimentally that second-order, third-order, or in general, higher-order respondent conditioning is possible. Once the first-order conditioned stimulus-response relation has been established it is then possible to pair the firstorder conditioned stimulus with another conditioned stimulus. The establishment of new S-R relations through respondent conditioning might be said to add to an individual’s behavioral repertoire in the sense that although not novel, the response is now being elicited by a different stimulus. Except for those respondent relations where the response is a strongly emotional one, a respondent S-R relation is not what could be called a longlasting relation. Once the respondent relation is established, repeated occurrences of the conditioned stimulus without the unconditioned stimulus weaken the S-R relation until the conditioned stimulus elicits no response. This process is known a respondent extinction. The only way to re-establish the relationship is to go through respondent conditioning all over again. Of course, the original reflex relation is left undisturbed. While respondent conditioning seems to play a role in developing taste aversions, sexual arousal, and phobias, little is known about what role it plays in language development and everyday language behavior. It may play some role in words acquiring emotional connotations, but little else. That does not mean that there has not been much speculation in the past about its function with respect to language behavior. Nevertheless, textbooks on applied behavior analysis and speech-language disorders usually have little to say about respondent S-R relations or establishing them for therapeutic purposes. The application of respondent conditioning in speechlanguage interventions seems to be extremely limited, since only the stimulus is changed in the stimulus-response relation, not the behavior. Usually speech-language interventions involve changing the behavior of the client, such as correcting for misarticulations. To achieve changes in behavior requires the establishment of operant relations. Operant Relations “Men act upon the world, and change it, and are changed in turn by the consequences of their action.” (Skinner, 1957) Skinner’s quotation captures the essence of how most human behavior occurs, is maintained, shaped, changed, ela borated on (i.e., made more complex), refined, and enlarged or contracted in its repertoire. Behavioral repertoires are largely created and maintained through an individual’s interactions with the physical and social environment. Traditionally, we refer to this kind of behavior as voluntary behavior, in contrast to reflexive behavior. This kind of behavior is called operant behavior in behavior analysis. Operant behavior is a function of its consequences 136 SLP- ABA Volume 5, Issue No. 2 and is much more complex than reflexive behavior in that the operant S-R relations involve both antecedent stimuli and consequent stimuli, as will be shown below. Consequent Stimuli. The following is an illustration of how a consequent stimulus can affect behavior. An infant is placed on her back in a crib. Typically, when placed in such a position the infant will randomly move her arms and feet and look around in what could be called uncommitted or emitted behavior (Cooper, Heron, & Heward, 2007). Above the infant and within her visual field is a motionless but colorful mobile. After a while she may habituate to her surroundings and eventually stop her activity and even fall asleep. Let us now tie the end of a ribbon to her right leg and connect the other end to the mobile, so that every time she moves her right leg the objects hanging from the mobile will be set in motion. The first time she moves her right leg the motion of the mobile will attract her attention. Pretty soon she is regularly moving her right leg to initiate the movement. The more vigorously she moves her leg the more movement in the mobile. Notice that the behavior is first initiated randomly. We have no evidence that there are any eliciting stimuli. Yet now the behavior is repeated because of its consequence(s). Traditionally we say that the infant is engaging in purposeful or intentional behavior. What was once a random movement of the right leg has become a regular, “purposeful” activity. Reinforcement. The consequence of the behavior, the moving mobile, has come to function as a positive reinforcing stimulus , also called a positive reinforcer, for the generation of an operant behavioral repertoire (right leg movement). Technically speaking, consequent stimuli that are positively reinforcing are those that increase the probability that the response will occur again under similar circumstances. Consequent stimuli that decrease the probability that a response will reoccur are called punishing stimuli or punishers . For example, if a mother gently slaps (aversive stimulus) her young son’s hand as he reaches out to grab something his mother doesn’t want him to touch, the child will withdraw his hand. He might try several times more to reach to the object, but each time he gets slapped, perhaps a little harder. After a while, he no longer reaches out for the object. Each slap (the aversive punishing stimulus) is reducing the likelihood of his reaching out for the object. On the other hand, if a response leads to the removal of an aversive stimulus, the probability of the response is likely to increase when similar aversive contingencies occur. In such cases, the aversive stimulus is often referred to as a negatively reinforcing stimulus or negative reinforcer. Reinforcing stimuli can be classified on the basis of their origin (empirical source) or their formal characteristics (Cooper, et al., 2007). In classifying reinforcing stimuli on the basis of origin, two types are identified: unconditioned (positive or negative) reinforcers and conditioned (positive or negative) reinforcers . Unconditioned reinforcers, also known as primary reinforcers, are those that that are not learned. In other words, such stimuli have been established as reinforcers through the process of natural selection over the evolutionary history of a species. Food, water, and sexual stimulation are frequently cited as examples of unconditioned reinforcers. Just what other stimuli are unconditioned reinforcers is difficult to specify for the human species, because few empirical studies have attempted to sort them out. It has been suggested that touch and some facial gestures, like the smile, may also be natural reinforcers, but the evidence is not strong enough to know for sure. Conditioned reinforcers, also known as secondary reinforcers, are stimuli that were originally neutral but became reinforcing by being paired either with unconditioned reinforcers or previously conditioned reinforcers. Perhaps one of 137 SLP- ABA Volume 5, Issue No. 2 the most well known examples of a conditioned reinforcer is money. Conditioned reinforcers like money are referred to as generalized conditioned reinforcers because they have been paired with so many different unconditioned and other conditioned reinforcers. In terms of formal characteristics reinforcers can be divided into (1) tangible reinforcers , that is, those things that can be touched, seen, smelled, and manipulated; (2) edible reinforcers , that is, anything that can be eaten; (3) activity reinforcers , such as playing games by oneself or with others, reading, attending a concert, playing with friends, engaging in artistic endeavors, and so forth; (4) social reinforcers , such as physical contacts like hugs and pats, proximity to others, attending, and verbal stimuli like praise. Obviously social reinforcers are provided by other people and are probably among the most useful of the conditioned reinforcers for certain kinds of clients. Antecedent Stimuli. Now let us complicate the previous situation of the infant and the mobile to show how contingent (non-eliciting) antecedent stimuli can influence behavioral responses. Let us say that during the time the infant was in her crib and engaged in these activities, a red light was on. After the reinforcing relationship has been established between the motion of her right leg and its consequence, we turn off the light and arrange things so that any further movement of her right leg does not result in setting the mobile in motion. After a while, the movement of her right leg will become less frequent and predictable , i.e., the reinforcing relation has been extinguished. But if we turn the red light on again and allow again movement in her right leg to cause the mobile to move, we will soon observe the infant’s right leg moving as frequently and as predictably as before. In other words, we have established the reinforcing relation between the be havior (right leg movement) and its consequences (setting the mobile in motion) but only if the red light is on. Now when we turn the light off, we will find that the infant does not move her right leg, or more likely, moves her leg but with much less frequency and certainly with less regularity then when the light is on. This example illustrates how antecedent stimuli can come to control operant behavior as a result of stimulus discrimination training, that is, reinforcing behavior in the presence of one antecedent stimulus but not in the presence of another. Through discrimination training a new stimulus-response relationship has been created between the presence of the antecedent red light and the behavior. The antecedent red light is said to occasion or evoke the behavior, that is, make it more likely to occur. The red light is said to be functioning as a discriminative stimulus . The behavior under the control of the discriminative stimulus is referred to as the discriminated operant. After an antecedent stimulus has come to evoke a particular response under contingencies of reinforcement, other stimuli are also likely to evoke the same response. This empirical principle is called stimulus generalization. These other stimuli usually share some common properties with the controlling stimulus, although the evocative strength of these new (unconditioned) stimuli may not be as great as the original controlling stimulus. In the just given example of stimulus discrimination, the infant learned that right leg movement was reinforced when the red light was on but not when the light was off. However, lights of other colors might now also evoke leg movement with the strength (frequency) of the leg response varying depending upon how close the color is to red. Stimulus generalization can also be seen in language learning. Once a child has acquired a new word, it will be evoked over a wider range of 138 SLP- ABA Volume 5, Issue No. 2 stimuli than it would be evoked in adult speech. For example, one child learned the word “fly” in the context of the common household insect, but then on other occasions used the same word in the context of any small insect, crumbs, and even her own toes. Linguists often refer to such language behavior as overextensions, but such behavior conforms very well to the concept of stimulus generalization. Schedules of Reinforcement. A reinforcing stimulus following some behavior increases the likelihood of that behavior occurring in the future. But for how long will the behavior reoccur, given the appropriate conditions? The answer to this question will depend on the past contingencies of reinforcement, that is, the frequency with which the behavior is reinforced. The rate at which reinforcement occurs is called a schedule of reinforcement (Ferster & Skinner, 1957). A continuous reinforcement (CRF) schedule is one in which an operant response is reinforced every time it occurs. There are also several varieties of intermittent reinforcement schedules, each with their own special characteristics. Interval schedules are arranged according to the interval of time that has passed after an appropriate response occurs, regardless of the number of other appropriate, or even non-appropriate, responses that have occurred in that interval. A fixed interval schedule (FI) is one in which the occurrence of the reinforcing stimulus depends on a constant time interval following an appropriate response, such as five minutes (FI5) or ten minutes (FI10). On the other hand, a variable interval schedule (VI) is one in which the interval of time is not constant but can vary around an average. For example, a VI10 means that on average reinforcement is occurring every 10 minutes after an appropriate response, but an actual interval might be shorter or longer than 10 minutes. Ratio schedules are arranged according to the number of appropriate responses that have occurred, regardless of time. Just like interval schedules, ratio schedules can be fixed (FR) or variable (VR). For example, an FR1 means that every appropriate response is being reinforced, i.e., continuous reinforcement, while an FR10 means that every 10th appropriate response is being reinforced. A VR15 means that on average every 15th response is being reinforced. Behavior that is continuously reinforced will have a very high probability of reoccurring and will be strengthened faster than on an intermittent schedule. If reinforcement is withheld, extinction of the behavior will occur quite rapidly. Responses on a continuous schedule of reinforcement also tend to have very little variation in their topography and thus tend to be rather stereotypical. Furthermore, while in laboratory and clinical settings, behavior on a continuous reinforcement schedule will fairly often be employed in certain circumstances, one rarely finds them occurring in natural settings. Unlike a continuous reinforcement schedule where high rates of responding can be quickly generated, the rate of responding takes more time to build up with intermittent reinforcement. Nonetheless, response rates under intermittent reinforcement also eventually reach high probabilities of occurring under appropriate circumstances. An advantage of an intermittent schedule of reinforcement over CRF is that the behavior will persist longer and be more resistant to extinction. Comparing the different intermittent schedules, experimental evidence suggests that behaviors under variable schedules (VR and VI) of reinforcement, are likely to be more resistant to extinction than those under the fixed schedules (FR and FI), as long as the average ratio or average interval is not too great. Various kinds of intermittent schedules of reinforcement are more likely to be found in natural settings than CRFs. This explains in part why much of our operant behavior persists over time, including language behavior. It should also be kept in mind 139 SLP- ABA Volume 5, Issue No. 2 that within our behavioral repertoires different operants are subject to different schedules of reinforcement and that schedules may change over time. The Three-Term Contingency. Operant S-R relations, thus, usually involve what is called a three-term contingency, sometimes symbolized as SD→R→SR, where SD is the discriminative stimulus, R, the response, and SR, the reinforcing stimulus. According to this “formula,” the occurrence of some behavior is highly probable (other conditions being present) when a certain antecedent (discriminative) stimulus is present as the result of a past history of the behavior being contingently followed by a reinforcing stimulus under some schedule of reinforcement. The three-term contingency formula for operant conditioning looks deceptively simple, which is probably one of the reasons why many linguists and cognitive psychologists, as well as others, have difficulty conceiving that operant conditioning could be the basis for language behavior. What I have presented here is only the bare basics of the principles of operant conditioning. For details, see Catania (1953), Cooper, et al (2007), Fester & Skinner (1957), Pierce & Cheney (2008), Skinner (1953), or Sulzer-Azaroff & Mayer (1991). Two Poverty of the Stimulus Arguments “It is perhaps worth emphasizing that the orderly control of behavior in a stable environment by contingencies of reinforcement is not a theory but an empirical fact.” (Palmer, 1998) After 23 years of working on it, B. F. Skinner (1957) wrote Verbal Behavior, a 478- page exposition of how language behavior could be explained in terms of operant principles. Actually, Skinner avoids using the term ‘language behavior’ in his book (1957, p. 2) because for him ‘language’ refers to the practices of a linguistic community and his focus is on the verbal behavior of the individual. Also his use of the term verbal behavior is broader in conception than just spoken language.. Unlike linguists, Skinner did not try to define nor describe language or linguistic units in structural terms or in terms of formal rules for generating and comprehending language forms. Instead, he tried to characterize language behavior in terms of the sources that provide the reinforcing stimuli and discriminative stimuli for the behavior. As he put it (Skinner, 1957, p. 2), language behavior is “…behavior reinforced through the mediation of other persons…” In other words, it is the members of a language community who provided the stimulus control and reinforcement necessary for an individual to become a member of and to maintain membership in that community. Later in Verbal Behavior (pp. 224-226), Skinner refined his characterization to make it clear that language behavior of the speaker was a special repertoire tied to a listener whose own language behavior was shaped by a community of speaker-listeners (Palmer, 2008). Unlike cognitivists and linguistic nativists, Skinner did not put the structures and the rules or principles that supposedly govern language behavior in the head. Instead, in describing language behavior in terms of the environmental (physical and social) variables that give rise to such behavior, he gave full responsibility for the phonological and grammatical patterns in language behavior to the language community, through its control over the contingencies of reinforcement. 140 SLP- ABA Volume 5, Issue No. 2 Arguments critical of explaining language behavior in terms of operant S-R relations might be said to have begun soon after the publication of Verbal Behavior and quickly culminated with Chomsky’s review of that book (Chomsky, 1959). Over the ensuing decades these arguments became more refined and new ones were added, becoming known as the poverty of the stimulus arguments (Chomsky, 1980; Thomas, 2002). The poverty of the stimulus arguments might be regarded as a multi-bladed Excalibur with which the knights of linguistic nativism try to slay the empiricist dragon. Only those considered most pertinent to the issues of concern of speech-language pathologists and applied behavior analysts will be discussed here. It has been argued by Chomsky and others that explaining the ontogenetic development of language behavior (i.e., language acquisition) in terms of establishing operant S-R relations in a child’s interactions with speaking members of a language community is insufficient and furthermore, that the structural complexities of speech utterances (i.e. the grammar of language) are too great to be learned through verbal stimuli. 1. Language behavior is stimulus-independent. Chomsky (1972) stated that language behavior is “…free from control of detectable stimuli, either external or internal.” (p. 12.) This is such a radical claim that one might well wonder if there is any empirical support for it. Unfortunately, Chomsky provides no such evidence. Previous to making this claim, Chomsky (1972) discusses another “important observation.” The observation is that “…the normal use of language is innovative, in the sense that much of what we say in the course of normal language use is entirely new, not a repetition of anything that we have heard before and not even similar in patternin any useful sense of the terms “similar” and “pattern”to sentences or discourse that we have heard in the past” (pp. 11-12). Again just what evidence there is to support this claim is not stated. In fact, Chomsky speaks of this observation as being a “truism.” Chomsky treats the stimulus-free aspect and the novelty of language behavior as being independent observations. Logically it seems that if language behavior were not under the control of stimuli then it would be natural to expect much novelty in language behavior. Nonetheless, Chomsky claims that language behavior is always coherent and appropriate to the situation. These properties are apparently intended to rule out language behavior that is random or not in conformance with the grammatical principles of the language system. It is interesting to note that Chomsky rules out the possibility of the coherence and appropriateness of language behavior being controlled by external stimuli, specifically the language community. Instead he lets coherence and situational appropriateness remain inexplicable mysteries by saying, “Just what “appropriateness” and “coherence” may consist in we cannot say in any clear or definite way, but there is no doubt that these are meaningful concepts.” (p. 12) While there seems to be little, if any, empirical evidence for stimulus-independent language behavior, there is plenty of empirical evidence for language behavior being stimulusdependent, particularly in the language acquisition process. Microanalytical studies of the dyadic conversations between children and their parents have shown that (1) children are relying on cues from the immediate conversation for building up their speech repertoires; (2) parents are providing models of speech patterns that show up later in the child’s speech; (3) when a child’s verbal response is grammatically incorrect, the parent will frequently follow up with an utterance similar to what the child said but recasted in the correct grammatical form, thus providing a mechanism for shaping the child’s language repertoire. Mediated reinforcing stimuli take many forms, such as fulfilling a child’s verbal request and providing various social reinforcements 141 SLP- ABA Volume 5, Issue No. 2 when the child responds appropriately. For example, when the parent asks the child a question and the child replies appropriately or when something in the environment, such as a object or event, or a property of either evokes a verbal response from the child that is deemed appropriate, the parent then responds with such expressions as “yes,” “right,” and so forth, possibly followed by a recast. If there was something grammatically wrong in the child’s reply, just recasting or even expanding on what the child said often seems to be sufficient for the child to self-correct eventually. It might be worth mentioning here that this is probably the way by which children begin to distinguish between what linguists refer to as grammatical and ungrammatical utterances. Later their “sense of grammaticality” is refined largely through the contingencies of reinforcement provided by the educational system. These findings are not what one would expect if language behavior were stimulus-independent (Moerk, 1992, 2000). 2. Primary linguistic input is limited and degenerate. Nativists use the term “degenerate” to refer to the fact that in everyday conversations speakers fairly often make mistakes in pronunciation and vocabulary selection, do not speak in full sentences, but in fragments, hesitate, start an utterance, stop, and begin anew, and in general make a number of errors. In addition, the range of grammatical constructions that listeners hear is limited. How then, nativists ask, could a child possibly construct a mental grammar of their language that would allow them to produce and understand virtually any utterance in their language? The preceding question raised by nativists clearly reveals the difference between the theoretical predispositions of nativists and behaviorists. Behaviorists make no assumption about the existence of any innate, species-specific, mental mechanism for grammar construction. They assume that language behavior arises, is maintained, and changes through the interactions between an individual and other members of his/her language community. For behaviorists there are no internal rules and representations or principles and parameters for generating linguistic utterances or for responding to linguistic utterances; there is only the history of contingencies of reinforcement for such behavior by the verbal community and the current circumstances or setting in which such behavior occurs. Clearly behaviorists and nativists stand apart in their theoretical claims. But the crux of the difference between them seems to be in their empirical claims and the strength of the evidence that supports them. The empirical evidence for the linguistic input being limited and degenerate seems to be very weak. Studies of the interactions between children in the process of learning their first language and their parents or other members of their language community strongly suggest a great richness in the quality and quantity of the antecedent and consequent stimuli. Far from being anomalous, messy, and full of errors as adult speech is claimed to be, these studies of parent-child verbal interactions going back at least as far as the early 1970’s (Snow, 1972) have shown that parent’s modify their language behavior when interacting with children so that their speech is simpler, less lengthy, more careful, less complex, and more repetitious. Moerk (1992) found that as children develop in their language behavior, the speech of the parents becomes more complex, staying somewhat ahead of the complexity of child’s speech, as if providing a goal for the child to reach. In addition, a study of the quantity of the parent-child interactions (Hart & Risley, 1995) , involving 42 children from three different social classes from the ages of 13 months to 36 months, found that the children were verbally engaged with their parents at an average rate of 341 142 SLP- ABA Volume 5, Issue No. 2 utterances per hour. These utterances contained numerous kinds of morphological and syntactic structures and numerous kinds of sentence types. Although a complete analysis of the verbal interactions between each parent and child has yet to be done, their study reveals a tremendous richness in the children’s linguistic input. Richness of input is necessary but hardly sufficient for a child to learn a language. Studies have shown that children just listening for hours and hours to another language do not show much progress in learning the language beyond perhaps having some rudimentary understanding of a few words or expressions. Learning a first language also demands a rich situational context and much feedback and interaction between the speaker and listener with a frequent reversal of speaker-listener roles. In more behavioral terms, learning language behavior requires interactions between the child and his or her social and physical environment where operant S-R verbal relations can be established and maintained. The Relevance of Operant S-R Relations to Speech-Language Interventions Speech-language interventions have four basic aims: (1) to increase desirable or target verbal behaviors; (2) to decrease undesirable verbal behaviors; (3) to establish desirable verbal behaviors when such behaviors do not occur in the client’s behavioral repertoire; and (4) to provide the means for the clients to maintain the desirable verbal behaviors in their everyday life after treatment is over. To achieve these aims, Hegde (1998) distinguishes between treatment principles and treatment procedures. Treatment principles are verbal inductive generalizations or rules that are the outcomes of experimental analyses of operant behavior. Thus, they are focused on the conditions under which operant S-R relations are established and maintained. The treatment procedures are those intervening interactions that a clinician carries out with a client to bring about changes in the behavior of the client. In this process, not only is the client’s behavior changed, but the clinician’s own behavior will also be altered as a consequence of the client’s responses as he or she determines which discriminative and reinforcing stimuli are effective in altering the client’s behavior and which schedule of reinforcement is most suitable for the maintenance of the new behavioral repertoires. Treatment procedures might be said to be where the rubber meets the road. They are the specific steps taken by the clinician in implementing the empirically based principles on a caseby-case basis in carrying out language interventions. Because the treatment principles are empirically well founded, valid, reliable, and replicable, they are what license or legitimize the use of the treatment procedures. Treatment procedures need to be tailored to the client because each client is an individual and will respond differently owing to the unique aspects of his or her physiology and history of past contingencies of operant interactions with the physical and social environments. Hegde (1998) points out that there are many operant principles that suggest ways to carry out speech-language behavior interventions. The principle of positive reinforcement can be applied to increase the probability of desirable or target speech-language behaviors, such as community acceptable word pronunciation. One of the problems a speech-language clinician faces is determining what are the appropriate positive reinforcers for a particular client. Some clients, initially at least, respond better to certain primary reinforcers, while other clients might 143 SLP- ABA Volume 5, Issue No. 2 respond better to conditioned reinforcers, based on their past history of contingent reinforcement. For example, a clinician working with an autistic child who has tended to not interact well with other people and who displays little or no verbal behavior might make use of one or more primary reinforcers such a food or objects such as toys that the child shows some interest in and allowing access to them when the child responds in some verbally desirable way, like saying “Please.” Gradually the clinician can switch to conditioned reinforcers, particularly social reinforcers. Some undesirable behaviors can be removed from a client’s repertoire through extinction. If these are operant behaviors, reinforcers must control them. By finding out what they are the clinician can withdraw these stimuli and thus bring about extinction of the behavior. Differential reinforcement can help by replacing the undesirable behavior with more desirable behavior. Another approach to removing undesirable behaviors is to follow such behaviors with aversive stimuli (punishers). There are some advantages to punishment of undesirable behavior. The behavior is rapidly extinguished and is not likely to reoccur. However, using punishing stimuli has a downside to it. It may engender other unacceptable behaviors, such as aggression, anger, even withdrawal from interaction. The use of punishment should be decided on a case-by-case basis and great care must be taken not to overuse it. For reinforcement to be effective in building or altering a language repertoire, the target verbal behavior must first be emitted. But what if the target behavior is not in the client’s current repertoire or occurs too infrequently to make practical use of it? In situations like these the clinician needs to apply procedures that can result in new verbal behaviors being added to a client’s language repertoire. The kinds of procedures that are appropriate will depend on assessing the current nonverbal vocal behavior, language repertoire, and learning and social skills of the client. If a client already demonstrates some emitted vocal skills but exhibits little language behavior, then the verbal modeling-imitation procedure may be quite useful in the development of such behavior. As was pointed out earlier, Skinner (1957) defined verbal behavior as behavior that is mediated by other persons. In verbal modeling-imitation, a model is a verbal response produced by one person and the imitation is the evoked verbal response that is topographically similar to its modeled stimulus, produced by another person. In the example presented earlier, the red light (the SD ) evoked the infant’s leg movement (R) after the behavior was differentially reinforced in the presence of the light but not in its absence. Note that formally or topographically, there was no resemblance between the red light and the infant’s leg movement, but not in the case of modeling-imitation, where the antecedent verbal stimulus and the verbal operant share common topographical properties, in this case acoustic ones. Skinner (1959) called such verbal operants echoics . Others may refer to them as verbal or vocal imitations. Modeling-imitation can be seen in the pre-linguistic and early stages of language development. Young children, infants and toddlers, frequently get socially reinforced for vocalizing in ways that are similar to or echo adult speech. For example, a mother that hears her young daughter babble the uncommitted vocal response “dada” will suddenly pay more attention to her child, show excitement, smile brightly, gently touch or pat, and even hug her child, and say “Yes, dada.” Some or all of these parental responses may provide reinforcement for the child to repeat “dada.” Soon the child is saying “dada” whenever the mother says to her “Say, dada” under some schedule of reinforcement. Thus, “dada” has become a discriminated verbal operant. In fact, this kind of interaction can become generalized, such that whenever the mother says “Say, mama,” or “Say, doggie,” or, in general, “Say, X,” the child will repeat back (echo) whatever X is. 144 SLP- ABA Volume 5, Issue No. 2 Through this generalized procedure new verbal responses are being added to the child’s language repertoire. Modeling-imitation also has applications in speech-language interventions. For example if a client is having difficulties with pronouncing certain words or longer expressions, the model discriminative stimulus provides a standard that can be used for correcting the problem. It may also be used in dealing with a client’s morphological or syntactic problems. Most people would not consider a child’s echoic responses to have any particular informative value , that is, we would hardly consider the verbal echoic episodes between the mother and her daughter as conversations. Nevertheless, echoics are a part of language behavior. Echoic behavior, either complete or partial, plays various roles in adult verbal episodes, such as when quoting someone else, expressing surprise, reassuring that one is paying attention, concurring or showing understanding, taking vows and oaths, repeating to gain time to respond, and so forth (Winokur, 1976). Furthermore, echoics are extremely valuable in both normal language development (see Hegde, in this issue, and McLaughlin, in this issue) and language interventions as a jumping off stage for developing other kinds of verbal operants that are more involved in verbal interchanges. Among a number of verbal operants, Skinner (1957) distinguished between two primary ones: tacts and mands. Tacts are verbal operants that are evoked by the presence of discriminative stimuli, such as objects, events, or properties of objects and events, spatial, temporal, and other relationships or combinations of these. In other words, tacts are verbal operants for whatever there is in our universe of discourse. Mands are verbal responses that are evoked under conditions of deprivations or aversive stimuli. The form of the mand often specifies or tacts its reinforcer, making it possible for another member of the verbal community to respond as a reinforcement mediator to supply the reinforcer specified by the mand. Linguistically a mand can be as simple and as short as a single word “Cookie!” or as long as a sentence “Would you go into the bedroom and get my green slippers?” or even longer. To establish tact and mand verbal operants as part of the language repertoire of a child with only echoic behavior requires the use of transfer of control procedures (Sundberg & Partington, 1998). To illustrate such a procedure the earlier “dada” example, where a child acquired a repertoire of echoic behaviors, will be expanded on. Now the father is present in the room. The mother points to the father and says, “Who is this? Dada. Say, dada.” The child echoes “dada” and is socially reinforced with big smiles, verbal praise, and perhaps some physical contact from one or both parents. After some similar episodes, the echoic prompt can be faded out, while keeping the prompt “Who is this?” Later, when the father is alone in the room with his daughter, if she utters “dada” without any prompts at all, her behavior is reinforced. In this way, transfer of stimulus control from the verbal antecedent stimulus prompts to the presence of the father is accomplished. The initial model antecedent stimulus acts as a kind of catalyst to establish a new operant relationship in which the presence of another antecedent stimulus comes to evoke the original echoic response. Once the child has learned tact relationships, the transfer of control procedure is no longer necessary. Instead, the child can start acquiring more tacts by observing adults and other children tacting in the presence of discriminative stimuli. This is another kind of verbal modeling-imitation that is frequently observed in language development. If the child has also learned mand relationships, she can start asking for the names of things, 145 SLP- ABA Volume 5, Issue No. 2 perhaps first by pointing and than later verbally by asking, “What’s that?” Mand verbal operants can be learned in a similar way but with the added complication that a deprivation or aversive antecedent stimulus must be already present or must be established by the clinician, so that transfer of control can eventually be made to it. Human beings like other living organisms interact with the physical world and thus their behavior is subject to the contingencies of reinforcement and stimulus discrimination the physical world provides. But more than any other species human beings interact with their fellow human beings and are subject to the contingencies of reinforcement and stimulus discrimination of the language behavior of others. And once such behavior has been established, we learn to behave both verbally and non-verbally, according to the verbal instructions of others. Verbal instructions, whether vocal, written, or gestured, are stimuli that describe or specify occasioning discriminative stimuli, the evoked responses they control, and their consequences or some combination of these (Skinner, 1969). Verbal instructions have also been called contingencyspecifying stimuli (Schlinger & Blakely, 1987) or rules (Skinner, 1969). The behavior that they evoke has been called by Skinner (1969) rule -governed behavior and by Catania (1998) verbally governed behavior. The linguistic form that verbal instructions can take is highly varied, ranging over such traditional sentence types as declaratives, interrogatives, and imperatives. We learn many skills via the model- imitation route, but many more are acquired through instructions or a combination of modeling and instruction. For example, a manual of English pronunciation might describe how to pronounce the “f” sound as follows: Spread your lips a little and gently bring your lower lip up against your upper teeth; then breath out through your mouth without vibrating your vocal cords. If a clinician gave the same instructions to a client who is having difficulty pronouncing this sound and the client has had a long history of being reinforced for following verbal instructions, there is a good chance that the client would correctly pronounce the target sound. If the client still has problems, the clinician can model the articulation of sound, providing a visua l stimulus for the client to imitate. Also the acoustic result of the articulation of the sound by the clinician results in an auditory stimulus that provides the client with a model for the resulting auditory effect of his or her own production. Another means of adding new behaviors to an individual’s repertoire is shaping. Not all clients are able to acquire new behaviors using the modeling-imitation procedure, nor are all clients able to follow verbal instructions well. Shaping is a technique for adding new behaviors in a step-by-step fashion using differential reinforcement. Skinner (1953) compares the shaping of emitted behaviors into new complexes of behavior through differential reinforcement of successive approximations to the desired terminal behavior to the shaping of a lump of clay by a sculptor into a piece of artistic design. Teaching language skills to autistic and cognitively deficient children (Sundberg & Partington, 1998) and rehabilitating the verbal skills of aphasic adults can be particularly difficult, but shaping can be an effective means of establishing verbal behavior. Starkweather (Starkweather, 1983) discusses shaping with the example of a five-year-old boy with no evidence of speech behavior, who did vocalize on some occasions and had a gestural repertoire for communicating his needs. He was brought to a clinic after being deprived of food for a while. His mother brought a sandwich and it was made known that he could have a bite of 146 SLP- ABA Volume 5, Issue No. 2 the sandwich at the pleasure of the clinicians. His gestures requesting the sandwich were ignored. Finally, he started whimpering a little. Immediately he was given a bite of the sandwich. Soon he varied his whimper with a kind of grunt, which was reinforced with another bite from the sandwich, but whimpers were no longer reinforced. It was not long before he was just grunting to get food reinforcement. Then the clinicians changed his reinforcement so that he was being reinforced only if he grunted with his mouth open, producing a vowel-like sound. The openmouth grunts varied in their vowel quality and then only the vocalizations with a short schwa-like quality were reinforced and not others. As the variation in his vowel-like sounds changed, some would be reinforced and not others and only if at the same time he pointed to a particular object and produced a certain vowel. Eventually he reached the behavioral point where he was being reinforced when he pointed to the sandwich and said /æ???/, which corresponded to the vowels in the word ‘sandwich’, each ending with a glottal stop. The shaping procedure continued until he could say the whole word correctly. As you can see, shaping can be a very onerous technique for teaching new behaviors. It takes a great deal of time, progress may not be as straightforward as a clinician might hope, constant monitoring is required, and the results may have some unintended consequences. The shaping procedure offers the best approach for initiating new behaviors with clients who do not imitate. With clients who do imitate, the modeling-imitation procedure is always more efficient. Various schedules of reinforcement are used for establishing and maintaining desirable behaviors. If the desirable behavior only occurs infrequently, continuous reinforcement can be used to strengthen and stabilize that behavior, such as was done in the case of the five-year-old child discussed by Starkweather. Once the desired behavior is regularly occurring in appropriate situations, it is then advisable to “thin” the delivery of reinforcement by gradually switching to an intermittent schedule of reinforcement to ensure that it will be maintained. As a goal, a highly variable schedule might be preferable because it generates responses that are highly resistant to extinction and also because variable schedules are more commonly encountered in natural settings. From the previous discussion it should be clear that speech-language pathologists and applied behavior analysts must rely on the operant conditioning methods to establish S-R relations to carry out language interventions. There is no other way to try to modify speaker or hearer verbal behavior repertoires. The successes that have been achieved by operant conditioning methods provide the reinforcing stimuli that keep practitioners continuing to rely on such methods and the well-founded empirical principles on which they are based. References Catania, A. C. (1998). Learning (4th ed.). Upper Saddle River: Prentice-Hall, Inc. Chomsky, N. (1959). Review of Skinner 1957. Language, 35(1), 26-58. Chomsky, N. (1972). Language and mind (Expanded ed.). New York: Harcourt Brace Jovanovich, Inc. Chomsky, N. (1980). Rules and representations. New York: Columbia University Press. 147 SLP- ABA Volume 5, Issue No. 2 Cooper, J. O., Heron, T. E., & Heward, W. L. (2007). Applied behavior analysis (2nd ed.). Saddle River, NJ: Pearson Education, Inc. Donahoe, J. W., & Palmer, D. C. (1994). Learning and complex behavior. Boston, MA: Allyn and Bacon. Ferster, C. B., & Skinner, B. F. (1957). Schedules of reinforcement. New York: AppletonCentury-Crofts. Hart, B., & Risley, T. R. (1995). Meaningful differences in the everyday experience of young American children. Baltimore, MD: Paul H Brookes Publishing Co. Hegde, M. N. (1998). Treatment procedures in communicative disorders (3rd ed.). Austin, TX: Pro-Ed. Moerk, E. L. (1992). A first language taught and learned. Baltimore, MD: Paul H. Brookes. Moerk, E. L. (2000). The guided acuisition of first language skills (Vol. 20). Stamford, CT: Ablex. Palmer, D. C. (1998). On Skinner's rejection of S-R psychology. The Behavior Analyst, 21(1), 9396. Palmer, D. C. (2008). On Skinner's definition of verbal behavior. International Journal of Psychology and Psychological Therapy, 8(3), 295-307. Pavlov, I. P. (1927). Conditioned reflexes (G. V. Anrep, Trans. paperback ed.). New York: Dover Publications, Inc. Pierce, W. D., & Cheney, C. D. (2008). Behavior analysis and learning (4th ed.). New York: Psychology Press. Schlinger, H. D., Jr. (1995). A Behavior analytic view of child development. New York: Plenum Press. Schlinger, H. D., Jr., & Blakely, E. (1987). Function-altering effets of contingency-specifying stimuli. The Behavior Analyst, 10(1), 41-45. Sechenov, I. M. (1965). Reflexes of the brain (S. Belsky, Trans. English ed.). Cambridge, MA: The M.I.T. Press. Skinner, B. F. (1953). Science and human behavior (Paperback ed.). New York: The Free Press. Skinner, B. F. (1957). Verbal behavior. New York: Appleton-Century-Crofts. 148 SLP- ABA Volume 5, Issue No. 2 Skinner, B. F. (1969). Contingencies of reinforcement: A theoretical analysis. New York: Appleton-Century-Crofts. Snow, C. E. (1972). Mothers' speech to children learning language. Child Development, 43(2), 549-565. Starkweather, C. W. (1983). Speech and language: Principles and processes of behavior change. Englewood Cliffs, NJ: Prentice-Hall. Sundberg, M. L., & Partington, J. W. (1998). Teaching language to children with autism or other developmental disabilities (Version 7.1 ed.). Pleasant Hill, CA: Behavior Analysts, Inc. Thomas, M. (2002). Development of the concept of "the poverty of the stimulus." The Linguistic Review, 19, 51-71. Winokur, S. (1976). A Primer of verbal behavior: An operant view. Englewood Cliffs, NJ: Prentice-Hall, Inc. Author Contact Information Raymond S. Weitzman 1035 E. Monticello Circle Fresno, CA 93720-1872 Phone: 559-438-6334 Email: [email protected] Behavior Analyst Online Is Looking For Financial Support The Behavior Analyst Online organization is seeking donors to support its cause. By contributing to the cost of the journals, you will help to keep our journals free. We plan to list our donors (if they desire) on the BAO site. The categories of donors are: Champion - $500.00, Elite - $250.00, Fellow - $150.00, Friend - $50.00 If you would like to contribute please contact Halina Dziewol ska at [email protected]. Please make check payable to Halina Dziewolska site funder raiser and send the check to 535 Queen Street, Philadelphia, Pa. 19147 149 SLP- ABA Volume 5, Issue No. 2 Behavioral vs. Cognitive Views of Speech Perception and Production Henry D. Schlinger, Jr. Abstract Speech perception and language acquisition have been studied primarily by cognitively oriented researchers. Many of these researchers discount a behavioral account despite facts demonstrating that speech in humans will not proceed typically or even at all in the absence of early exposure to a speech environment, and that reinforcing consequences from others as well from infants’ own vocalizations shape their vocal repertoires. In the present article, I illustrate a general behavior analytic approach to speech perception and production and contrast it with the more standard cognitive view. I suggest that cognitive accounts are not parsimonious in that they make assumptions about events and processes that are not testable and, thus, not falsifiable. I argue that a behavior analytic approach is not only parsimonious, but it is supported by evidence from both human infants and songbirds, and it is more likely to lead to practical applications. Key words: speech perception, speech production, behavior analysis, operant learning, statistical learning ______________________________________________________________________________ Introduction The study of speech perception and production has been dominated largely by cognitively oriented researchers and theorists. However, cognitive theories do not translate well into actually teaching speech and language. Because of its emphasis on behavior and its foundation of experimentally derived principles of learning, operant learning theory, on the other hand, has for more than 40 years been used to successfully teach speech and language, especially to people with a variety of speech and language disorders (e.g., Camarata, 1993; DeLeon, Arnold, Rodriguez-Catter, & Uy, 2003; Hegde, 1998; Hegde, 2007; Hegde & Maul, 2006; Johnston, & Johnston, 1972; Lancaster et al., 2004; Pena-Brooks & Hegde, 2007; Wagaman, Miltenberger, & Arndorfer, 1993). Although there is a fair amount of behavioral research on teaching verbal behavior to people with speech and language disorders, with few exceptions (e.g., Guess, Sailor, Rutherford, & Baer, 1968; Whitehurst, 1972; Whitehurst, Ironsmith, & Goldfein, 1974) behavioral scientists have not contributed much basic research on speech perception or production. What behavior analysis can offer language researchers and speech-language pathologists (SLPs) is a coherent and parsimonious interpretation of speech consistent with experimentally established scientific principles of learning that has immediate practical applications. The purpose of this paper is to illustrate a general behavioral approach to speech perception and production and to contrast it with the traditional cognitive account. The task of interpreting the traditional speech perception and production literature from a behavior analytic perspective is not as onerous as one might imagine, given that much of the research either incorporates relatively straightforward operant conditioning methods or methods that are amenable to an operant analysis. Contrasting Views of Perception Cognitive Views of Perception Traditional treatments describe sensation in terms of the effects of stimuli on sensory receptors. Perception, on the other hand, has generally been referred to as how the brain interprets sensory experience, or more formally as: …the process by which animals gain knowledge about their environment and about themselves in relation to the environment. It is the beginning of knowing and so is an essential part of cognition. More specifically, to perceive is to obtain information about the world through stimulation. (Gibson 150 SLP- ABA Volume 5, Issue No. 2 & Spelke, 1983, p. 2) The main problem with such descriptions is that gaining knowledge, knowing, and obtaining information are inferred solely from observable behavioral evidence and, thus, do not add much to our understanding. Moreover, placing perception inside the brain, as some descriptions do, only moves the level of analysis further away from the actual behaviors involved when one speaks of perception. And talking about the brain as if it is doing something – perceiving – is an example of what I refer to as the brain-as-person metaphor because organisms, not brains, perceive, that is, behave. Descriptions of the development of perception in infants are equally vague. For example, according to Gallahue (1989), “newborns attach little meaning to sensory stimuli” but very soon infants begin to attach meaning and attend to specific stimuli and to identify objects (p. 184). But what does that mean? These verbs do not refer to specific behaviors that can be studied but rather labels for a variety of behaviors. To understand what it means to attend, to identify or to attach meaning, we would need to observe what newborns actually do and the circumstances under which they do it when researchers use such terms. And we should not be surprised if the behaviors and circumstances vary considerably from instance to instance. Furthermore, such characterizations raise a more fundamental question: Why do infants begin to attach meaning or attend to specific stimuli? The traditional account offers no clear answer. Finally, the term perception itself is problematic. As a noun, it is usually considered a name for a process. But, of course, most of the time the only evidence for the process is the behavior that leads one to say that an organism has perceived something in the first place. In such cases, considering perception to be a process is an example of the logical error of reification. A Behavioral View of Perception Rather than debating the meaning of the term perception, a behavioral approach looks at what an individual does (and under what circumstances) that leads investigators to say that he or she perceives something. The focus is not on some inferred hypothetical construct, but rather on the actual behaviors from which such inferences are made. The advantages are obvious. Because the behaviors can be objectively described and measured, their causes can be potentially discovered and, as a result, can be manipulated as independent variables to change the behaviors. It is not possible to change one’s perception. Our principal question, then, is this: What is someone doing when he or she is said to “perceive”? For example, what does it mean to say that I perceive the computer on which I am writing the words you are reading? In other words, what do I do that causes someone to say that I perceive the computer? The list includes but is not restricted to looking at the computer, pushing the button to turn it on, moving the mouse, typing on the keyboard, and, importantly for verbal organisms, calling it a computer and describing it. Obviously, these behaviors usually, but not always, only occur in the presence of the computer, that is, while it is functioning as a set of visual, auditory, and tactile stimuli. (When these behaviors occur in the absence of the computer, we say that I am imagining it.) There are, however, many other stimuli impinging on my sensory receptors as I write at the computer, but until they influence some behavior on my part, we are not likely to say that I perceive them. For example, the sound waves produced by a car going down the street affect sensory receptors in my inner ear, but unless I do something like get up to see who it is, comment on it to someone else, or say to myself, “I wonder who just drove by,” I would not be said to perceive the car even though I sensed it. As this example illustrates, the sound of the car as a conditional stimulus (CS) or a discriminative stimulus (SD ) might evoke several different behaviors that would cause an observer to say that I perceived the car. Or, it might evoke no behaviors at all. Our senses are constantly bombarded by stimuli that are transduced into neural impulses, but we only perceive, that is respond to, a very small portion of them. Behavior analysts will recognize this as a relatively straightforward issue of stimulus control. The question for a science of behavior is: 151 SLP- ABA Volume 5, Issue No. 2 What causes us to respond to some stimuli but not others; in other words, what causes only certain stimuli to evoke behavior? Cognitive approaches to speech perception are problematic because they infer hypothetical constructs. A behavioral approach is more parsimonious because it infers potentially observable and manipulable interactions between behavior and stimuli. Cognitive Approaches to Speech Perception At this point in our evolutionary history, auditory perception is important for human beings primarily because we talk and listen. But as with perception in general, speech perception in particular has been studied within the conceptual framework of cognitive science. Consider the following description of the perception of a spoken word by Holt and Lotto (2008): The ease with which a listener perceives speech in his or her native language belies the complexity of the task. A spoken word exists as a fleeting fluctuation of air molecules for a mere fraction of a second, but listeners are usually able to extract the intended message. (p. 42, emphasis added) This short description embodies the essence of a cognitive approach to speech perception: that speakers have intentions, that words contain meanings , and that listeners must extract the intended meaning. Of course, the only evidence for extracting the intended meaning of an utterance is what the listener actually does. When this account is contrasted with a behavioral approach in which a speaker’s verbal behavior, itself evoked by the current circumstances (often including the presence of a listener), in turn evokes verbal (and nonverbal) behavior in the listener all because of a history of operant learning, it is not too difficult to understand why the behavioral approach has not fared well at all against the cognitive one. The cognitive account, despite its logical and scientific problems (see below), is the more familiar and accessible. It is also consistent with the philosophical tradition of mentalism with which we have all been raised. Even so, most language researchers discount any important role for operant learning in speech perception or production. Cognitive Views of “Skinnerian Learning” Modern language researchers do not put any stock in a behavioral account of speech perception or language acquisition. Some researchers still reference Chomsky’s (1959) review of Skinner’s (1957) book Verbal Behavior as demonstrating “the failure of existing learning models, such as Skinner’s, to explain the facts of language development” (Kuhl, 2000, p. 11852), despite the fact that Chomsky’s review was thoroughly rebutted decades ago (MacCorquodale, 1970; see also Palmer, 2006 for a brief history of the writing of Verbal Behavior, Chomsky’s review, and MacCorquodale’s rebuttal; see also Hegde in this issue). As I have written elsewhere: It seems absurd to suggest that a book review could cause a paradigmatic revolution or wreak all the havoc that Chomsky’s review is said to have caused to Verbal Behavior or to behavioral psychology. To dismiss a natural science (the experimental analysis of behavior) and a theoretical account of an important subject matter that was 23 years in the writing by arguably the most eminent scientist in that discipline based on one book review is probably without precedent in the history of science. (Schlinger, 2008b, pp. 335-336) Moreover, much empirical research since Chomsky’s review supports the behavioral view that parents and other caregivers behave in ways that shape and reinforce verbal behavior in young children (e.g., Whitehurst, Novak, & Zorn, 1972; Moerk, 1978, 1983, 1992; Hart & Risley, 1995, 1999). And speech-language pathologists have regularly used behavioral interventions to teach speech and language skills to children with articulation (speech) and language disorders (Hegde & Maul, 2006; Pena-Brooks & Hegde, 2007). In addition to citing Chomsky’s review, many language researchers perpetuate myths about 152 SLP- ABA Volume 5, Issue No. 2 Skinner’s view of language. For example, according to Kuhl (2000), On Skinner’s view, no innate information was necessary, developmental change was brought about through reward contingencies, and language input did not cause language to emerge . . .The emerging view argues that the kind of learning taking place in early language acquisition cannot be accounted for by Skinnerian reinforcement. (p. 11850) It is not clear what “innate information” means; if it means some presumed and unverifiable innate mechanism, Skinner may not have supported it. Skinner, however, never discounted the importance of well documented neurophysiological and genetic information – he believed that all behavior, including verbal behavior, was the combined result of inheritance and learning. But Skinner was neither a geneticist nor an evolutionary biologist (although he did write often about biology and evolution [see Morris, Lazo, & Smith, 2004]). Rather, his area of expertise was the effect of environmental contingencies on behavior. Thus, although Skinner emphasized the role of reinforcement contingencies on the behavior of a wide range of species, especially humans, he never claimed that developmental change was brought about solely through “reward contingencies.” And he most certainly did acknowledge the contribution of language input in language acquisition. But he did so within the confines of a unified account of behavior in general (see Skinner, 1957). Finally, as I argue below, there is no evidence that in any way suggests “that the kind of learning taking place in early language acquisition cannot be accounted for by Skinnerian reinforcement.” On the contrary, the kind of learning that takes place in early language acquisition can almost entirely be accounted for by operant learning principles. Elsewhere I have addressed some of the misconceptions of a behavioral approach to language (see Schlinger, 1995, pp. 178-182). Nonetheless, such misconceptions continue to be perpetuated by language researchers. One reason may be that behavior analysts have conducted very little of their own research on speech perception or language acquisition, except in the context of teaching children with language deficits (e.g., Learman et al., 2005; Sautter & LeBlanc, 2006). And much of the research conducted by behavior analysts has not been published in mainstream language journals. Also, many behavior analysts have been relatively content with interpreting the facts of verbal behavior, including research by traditional language researchers, according to the established principles of behavior analysis. Regardless of whether such an interpretation is correct, it has much to recommend it because it is parsimonious and firmly grounded in, and consistent with, experimentally established principles. But if behavior analysts themselves have not conducted much research into speech perception and production, other researchers have demonstrated, albeit incidentally, the critical role of operant learning, especially in speech production. For example, even though Kuhl (2000) claimed that “Skinnerian reinforcement learning” cannot explain how infants’ perceptual systems are altered by experience, elsewhere (e.g., Kuhl, 2004) she cited studies showing that social contact and interactions affect the duration, rate, and frequency of vocal learning in human infants and in songbirds. In particular, she cited a study by Goldstein, King, and West (2003) with human infants in whic h in a contingent condition “mothers were instructed to respond immediately to their infants’ vocalizations by smiling, moving closer to and touching their infants” (Kuhl, 2004, p. 837). Not surprisingly, at least to a behavior analyst, the results showed that when compared to infants in the non-contingent condition, infants in the contingent condition produced more vocalizations and more mature and adult-like vocalizations. This is obviously operant conditioning (Kuhl would call it “Skinnerian learning”) and it is consistent with previous research demonstrating that reinforcement, even in the absence of awareness, can strengthen (i.e., select) vocalizations and numerous forms of speech (e.g., Greenspoon, 1955; Rosenfeld, & Baer, 1970; Rheingold, Gewirtz, & Ross, 1959; Todd & Palmer, 1968). Even Goldstein et al. refer to it as “social shaping” (Skinner coined the term shaping to refer to the gradual differentiation of responses belonging to a response class as a function of differential reinforcement.). Other data from Goldstein’s lab confirm the powerful role of operant learning in early language acquisition (e.g., Goldstein, Schwade, & Bornstein, 2009). But such findings are not new (e.g., Rheingold, Gewirtz, & Ross, 1959; Todd & Palmer, 1968). Nonetheless, data such as these provide further support for the interpretation that infant vocalizations, 153 SLP- ABA Volume 5, Issue No. 2 including those called babbling, can be, and are shaped (i.e., selected) by consequences. The consequences for infant babbling and speech sometimes come from others, but the most relevant consequences are likely the match between the babbled sounds and those heard by the infant for the several months prior to the onset of babbling (see Schlinger, 1995, pp. 158-160; Hegde, this issue). There is simply no question that operant learning is a significant factor in language production. What Does It Mean to Say That Someone “Perceives Speech”? Whether we know it or not, most of the time when we say that someone perceives speech, we mean that his or her behavior is under the stimulus control of the speech. Some questions for a science of behavior are: 1) What form does the behavior take?; 2) What is the function of the behavior?; and, 3) How is such behavior acquired? At the most basic level, it could be said that infants perceive speech if they turn their head toward the location of vocal stimuli, although we would be hard-pressed to claim that infants are “extracting information” from such stimuli. Researchers often assess auditory perception in infants by using so-called habituation and dishabituation methods, for example, by measuring non-nutritive sucking or changes in heart rate, all of which, on the present account, qualify as perceptual behaviors. One example of a seemingly simple speech perception phenomenon that has received a considerable amount of attention from language researchers is categorical perception. The Strange Case of Categorical Perception Beginning in the late 1950s and early 1960s, researchers began to test the ability of both infants and adults to discriminate different categories of phonemes, a phenomenon called categorical perception. Traditional accounts view the phoneme as “the smallest unit of sound that signifies a difference in meaning in a given natural language” (Aslin, 1987, p. 68). Behavior analysts, on the other hand, view the phoneme functionally as “the smallest unit of sound that exerts stimulus control over behavior” (Schlinger, 1995, p. 153). For the present account, whatever behavior is evoked by the sound of a phoneme is what we mean when we speak of categorical perception. In early experiments, researchers used computers to present a series of synthetic consonant-vowel (CV) sounds that ranged across a number of consonants (e.g., /bV/-/dV/-/gV/). Specifically, the computer generated synthetic speech sounds that varied along a stimulus dimension called voice onset time (VOT), which is the basis of the distinction between CVs like pa and ba. Voice onset time refers “to the point at which vocal cords begin to vibrate before or after we open our lips” (Bates, et al., 1987, p. 152). Thus, for sounds we react to as b, voicing begins either before or simultaneously with the consonant burst; and in sounds that we react to as p, voicing begins after the consonant burst. A computer can present stimuli along this VOT continuum from -150 to +150 milliseconds (ms) from burst to voice. Results from numerous studies have shown that English-speaking adults and infants do not respond differentially to VOTs that fall either significantly above or below the boundary between pa and ba, which is about 25-30 ms. Results showing that infants only a few months old can respond differentially to these different phonemic categories suggested to some researchers that humans are born with “phonetic feature detectors” that evolved specifically for speech and that respond to phonetic contrasts found in the world’s languages (Eimas, 1975). Such results seemed to support nativist theories of speech and language (e.g., Chomsky, 1957) and were couched in such terms, which is understandable because Chomsky’s views on innate mechanisms of generative grammar still dominated the study of language in the 1970s. Results from other studies, however, have shown that nonhumans (e.g., chinchillas, monkeys, Japanese quail and even rats) could be trained to respond to these phonemic categories in the same way as human adults and children (e.g., Dooling, Best, & Brown, 1995; Kluender, Diehl, & Killeen, 1987; Kuhl, 1981; Kuhl & Miller, 1975, 1978; Kuhl & Padden, 1982, 1983; Reed, Howell, Sackin, Pizzimenti, & Rosen, 2003; Toro, Trobalon, & Sebastián-Gallés, 2005). Moreover, categorical perception in adults was 154 SLP- ABA Volume 5, Issue No. 2 limited to the phonemes in their respective native languages (Miyawaki et al., 1975), which suggests a strong experiential component. These studies with nonhuman animals forced a conclusion that ran counter to the prevailing views that somehow infants were born responding to phonetic units, and that language evolved in humans discontinuously with lower species; namely, that infants are born with a general capacity to discriminate auditory stimuli including speech sounds rather than one that evolved specifically for speech. Thus, domain-general, rather than species-specific mechanisms seem to be responsible for infants’ tendency to respond to phonetic units (Kuhl, 2000). As Kuhl (1981) stated, “the evolution of the sound system of language was influenced by the general auditory abilities of mammals” (p. 347). Or, as Bates, O’Connell, and Shore (1987) put it: We rushed too quickly to the conclusion that the speech perception abilities of the human infant are based on innate mechanisms evolved especially for speech. The infant’s abilities do indeed seem to involve a great deal of innately specified information processing. But we do not yet have firm evidence that any of this innate machinery is speech specific. We assumed that the human auditory system evolved to meet the demands of language; perhaps, instead, language evolved to meet the demands of the mammalian auditory system. This lesson has to be kept in mind when we evaluate other claims about the innate language acquisition device. (p. 154) What Bates et al. mean is that the development of speech perception in infants is constrained by what they are able to hear, and that the range of auditory stimuli detectable by the mammalian auditory system evolved for reasons having nothing to do with speech. Many language researchers now agree that the language environment exploits natural boundaries of a general auditory capacity that is common to mammals and some birds, but also can modify them (Diel, Lotto, & Holt, 2004). Thus, although initial studies on categorical perception were meant to support nativist theories of language development, such as Chomsky’s, further research supported the opposite conclusion, namely, that categorical perception resulted largely from experience and learning. In studies on categorical perception with both human infants and non-human animals, researchers successfully trained discriminative responses to phonemic sounds using operant conditioning procedures. One can assume, then, that similar contingencies operate naturally for human infants. The fact that adults respond only to phonemes in their respective native languages also suggests that those phonemes have specific functions that non-native phonemes do not, thus supporting the contention that operant learning is responsible. But that is not how cognitive researchers see it. Cognitive Views of Learning According to Kuhl (2000), “The acquisition of language and speech seems deceptively simple” (p. 831). By that she means that children learn their native language quickly and effortlessly. She wonders, then, how children, but not language theorists, are able to crack “the speech code” so easily. This is a little like asking how children began walking, negotiating the effects of gravity, before physicists understood the law of gravity. Nonetheless, Kuhl believes that the last several years has produced “an explosion of information about how infants tackle this task” . . . that would be surprising to and “unpredicted by the main historical theorists” (p. 831, emphasis added). Specifically, “children learn rapidly from exposure to language, in ways that are unique to humans, combining pattern detection and computational abilities (often called STATISTICAL LEARNING) with special social skills” (p. 831, emphasis added). It may come as a surprise to behavior analysts (who, I believe, are the “main historical theorists” Kuhl refers to) that after decades of uncritically adhering to Chomsky’s structural nativist view of language, many language researchers and theorists have done an about-face and now tout learning as the primary mechanism for language acquisition and speech perception (e.g., Kuhl, 2000). However, 155 SLP- ABA Volume 5, Issue No. 2 according to these scholars, this “new kind of learning” is not “Skinnerian learning.” Many modern language researchers now propose that certain aspects of language are experiencedependent (vs. experience independent), and even refer to the experience as “learning,” but instead of relying on empirically supported theories of (Pavlovian and operant) learning, they posit new forms of learning that are mostly human-language-specific (e.g., Saffran, Aslin, & Newport, 1996). To their credit, modern language researchers explicitly reject the assertion that similarities across languages (suggested by Chomsky) reflect innate linguistic knowledge and, instead, now believe that learning can explain them. But, oddly, these researchers attribute the similarities across languages not to already well-established general learning principles, but rather to poorly researched constraints on learning even while acknowledging that these learning mechanisms were not tailored solely for language (Saffran, 2003). So, what has caused language researchers to conclude that experience and learning (though not operant or Pavlovian learning) play a critical role in language acquisition and speech perception? What has changed over the last two decades to support these so-called “new views of learning” is the discovery that “by simply listening to language, infants acquire sophisticated information about its properties . . . ” (Kuhl, 2000, p. 11852), a phenomenon also referred to as “incidental language learning” (Saffran et al., 1997). Two examples of this “new kind of learning” are discriminative abilities in infants and so-called statistical learning (Kuhl, 2000). Discriminative Abilities in Infants The first example that illustrates the so-called “new views of learning” is that infants detect patterns or similarities in language input. Researchers cite evidence from a variety of studies, including the finding that at birth infants generally prefer to listen to the language spoken by their mothers during pregnancy and specifically to their mother’s voice over another woman’s voice, and to particular stories read by their mothers during the last several weeks of pregnancy (DeCasper & Fifer, 1980; DeCasper & Spence, 1986; Mehler et al., 1988; Moon et al., 1993; Nazzi et al., 1998). Other examples include the finding that by 9 months of age, but not earlier, infants prefer to hear prosodic patterns characteristic of their native language (Jusczyk, Cutler, & Redanz, 1993). Finally, infants have been shown to listen longer to words in their native language than to words in another language (Jusczyk et al., 1993). According to Kuhl (2000), “At this age, infants do not recognize the words themselves, but recognize the perceptual patterns typical of words in their language” (p. 11852). Such a locution, however, simply describes the research results and provides no explanation. And it is not clear how researchers know that infant recognize patterns but not words. Statistical Learning The second example of the “new views of learning language” is that “infants exploit the statistical properties of the input, enabling them to detect and use distributional and probabilistic information contained in ambient language to identify higher-order units” (Kuhl, 2000, p. 11852, emphasis added). This type of learning is called statistical learning by language researchers (e.g., McMurray & Hollich, 2009), and for Kuhl (and many other language researchers) it is the mechanism “responsible for the developmental change in phonetic perception between the ages of 6 and 12 months” (2004, p. 833; see also Maye, Werker, & Gerken, 2002). According to Kuhl (2000) : Running speech presents a problem for infants because, unlike written speech, there are no breaks between words. New research shows that infants detect and exploit the statistical properties of the language they hear to find word candidates in running speech before they know the meanings of words. (p. 11852) Researchers have demonstrated that by 6 months of age, infants who shortly after birth could universally be taught to discriminate between phonetic units, show a preference for the phonetic units of their native language (Kuhl, et al., 1992). In fact, researchers describe the changes in infant speech 156 SLP- ABA Volume 5, Issue No. 2 perception as a reduction in the ability to discriminate speech sounds that are not found in one’s native language. Because “the beginnings and ends of sequences (i.e., the segmentation) of sounds that form words in a particular language are not marked by any consistent acoustic cues” (Aslin et al., 1998, p. 321), such as pauses, and because the acoustic structure of speech across different languages is highly variable, researchers believe that a distributional rather than an acoustical analysis must be used to solve the problem of finding the words in a particular language. A distributional analysis refers to the regularities in the relative positions of sounds over a large sample of linguistic input (Aslin et al., 1998). For example, in English, “certain combinations of two consonants are more likely to occur within words whereas others occur at the juncture between words. Thus, the combination ‘ft’ is more common within words whereas the combination ‘vt’ is more common between words” (Kuhl, 2000, p. 11853). According to many language researchers, human infants need to discover the phonemes and words in a particular language. Because the speech they are exposed to is so variable and not marked by reliable acoustic cues, researchers believe that “infants use computational strategies to detect the statistical and pr osodic patterns in language input” (Kuhl, 2004, p. 831). Other researchers are quick to point out that infants are not consciously calculating statistical frequencies, but rather are sensitive to distributional information contained in the linguistic input to which they are exposed (Aslin et al., 1998). Notwithstanding this one disclaimer, most of these researchers seem to believe that the infants, or their brains, are extracting statistical information from the linguistic input. Based on the results of particular studies (e.g., Saffran et al., 1996), numerous researchers have concluded that, “infants use statistical information to discover word boundaries” (Aslin et al., 1998, p. 321), or they learn “from exposure to the distributional patterns in language input” (Kuhl, 2004, p. 835). However, such conclusions suffer from a number of logical and scientific problems. Problems With a Cognitive Account of Learning There are several logical and scientific problems with the cognitive account of speech perception and learning. The first concerns the issue of agency; that is, who does what. Cognitive accounts misplace the agency producing the effects inside the infant instead of in the linguistic environment which cognitive theorists clearly believe is critical for such learning. This is illustrated repeatedly in the literature in the way researchers talk about language learning infants. For example, Saffran et al. (1996) state that, “One task faced by all language learners is the segmentation of fluent speech into words” (p. 1927). According to Kuhl (2004), “infants use computational strategies to detect the statistical and prosodic patterns in language input, and that this leads to the discovery of phonemes and words” P. 831). Thus, as stated by these researchers, infants are faced with tasks, extract information, use or exploit strategies, abstract patterns, discover rules, and so on. Sometimes the task is assigned to the (infant’s) brain, which is said to be endowed with mechanisms that enable it “to extract the information carried by speech” and “use them to discover abstract grammatical properties.” (Mehler, Nespor, & P?na, 2008, p. 434). Either way, the locus of control is said to be within the individual. In essence, many of these researchers believe that it is the job of language learners to make sense of vague or complex information. This account is at odds with a natural science approach which looks for physical causes of behavior. Using an evolutionary analogy, it would be akin to saying that the task for individual organisms (or their brains) is to exploit strategies in order to discover the rules for how to survive in a complex environment. But ever since Darwin (and Wallace), we know that the direction of causation is the other way. The environment selects extant traits to the extent that on average those traits enable individuals possessing them to live long enough to pass on their genes. A selectionist account of language learning suggests that only some responses of infants to specific stimuli will produce desired consequences. Another problem with cognitive accounts of learning is that sometimes the questions are so confusing as to be essentially unanswerable. For example, Saffran (2003) asked what infants were actually learning in a segmentation task: “Are they learning statistics? Or are they using statistics to learn language?” (p. 112). The answer, of course, is neither. To understand what is wrong with these questions 157 SLP- ABA Volume 5, Issue No. 2 and with the notion of statistical learning in general, we must make a distinction between the researchers’ behavior and that of the subjects in experiments or infant in natural environments. It is true that a statistician or psychologist can statistically analyze conditional probabilities of certain sounds or arrangements of sounds within a stream of speech. But infants (or their brains) are not carrying out a statistical analysis based on the distributional patterns in the speech they hear anymore than they are calculating force, resistance, or gravity when they walk. The evidence that researchers cite is simply that hearing speech changes the behavior of infants. In reality it is the researchers who are doing the statistical analysis, not the infants. The principle of parsimony suggests that explanations of phenomena should make the fewest assumptions. But modern language researchers make many unnecessary and essentially untestable assumptions when they suggest that infants or their brains are statistically analyzing speech sounds. Just because a researcher can carry out a statistical analysis of speech sounds does not mean that is how infants learn from hearing the sounds. In addition to conceptual and logical problems with a cognitive account of speech perception, there are also methodological problems with some of the research. For example, the infants used in many studies on speech perception were already at least 6 months of age, which means they had at least 6 months (excluding prenatal exposure) of hearing speech and countless interactions with a vocal environment, which researchers acknowledge contributes to speech perception and language learning (Kuhl, 2000, 2004). Moreover, many of the studies trained infants, however briefly, to make discriminations or to show preferences, by reinforcing appropriate responses (although the authors rarely, if ever, referred to their training as operant conditioning). And, the general research paradigm in most of these studies is the hypothetical deductive one still common in psychology, which does not and cannot account for the variability from one infant to the next and therefore must pool (i.e., average) data. Such an approach obscures variation rather than refining experimental control to account for it (Schlinger, 2004). Finally, many of the very researchers who cite animal studies as evidence against a uniquely human capacity for speech perception claim that statistical learning is uniquely human. But studies employing operant contingencies have shown that even rats can be taught to perceive (i.e., discriminate) the nuances of speech (e.g., Reed et al., 2003; Toro et al., 2005). These animal studies further suggest that operant learning is a plausible explanation for how infants learn to discriminate speech sounds. A Behavioral View of Speech Perception As already stated, a behavioral view of speech perception stresses what an individual does when we say that he or she perceives speech and implicates general learning principles in the acquisition and maintenance of such behavior. In the infant laboratory, for example, the label speech perception is reserved for the behaviors researchers measure as responses to speech sounds, such as changes in heart rate and non-nutritive sucking. Outside the laboratory, the term speech perception is used to denote such behaviors as turning ones head in the direction of the speech, smiling, and making sounds. In sophisticated listeners, speech perception refers to a much wider range of behaviors from complying with requests to actually listening to what a speaker says, that is, subvocally echoing or otherwise talking to oneself (see Schlinger, 2008a). Over and above identifying the behaviors involved, “one of the most important issues in speech perception is how listeners come to perceive sounds in a manner that is particular to their native language” (Diel, et al., 2004, p. 164). As mentioned previously, newborn infants have been shown to prefer to listen to the language spoken by their mothers and specifically to their mother’s voice. By “prefer” researchers mean that infants will engage in behaviors that result in hearing the language spoken by their mothers during pregnancy, their mother’s voice more than another woman’s voice, and specific features of their mother’s voice over other features (DeCasper & Fifer, 1980; DeCasper & Spence, 1986; Moon et al., 1993; Nazzi et al., 1998). Thus, at birth or shortly thereafter, particular features of the infant’s native language in general and the mother’s voice in particular have become potent conditioned 158 SLP- ABA Volume 5, Issue No. 2 reinforcers in the sense that when such stimuli are presented contingently on some infant behavior (e.g., particular sucking patterns), that behavior increases relative to behavior that does not produce those features. These stimuli appear to become conditioned reinforcers (and perhaps acquire other behavioral functions as well) by simply hearing them; that is, it is not clear that pairing with other reinforcing stimuli is necessary. We do not need to appeal to a statistical analysis to explain these effects because as mentioned previously, it is researchers who impose those statistical properties after the fact. We also do not need to appeal to ad hoc cognitive processes, such as “perceptual representations of speech . . . stored in memory” (Kuhl, 2000, p. 11854) because the evidence for such explanations is only the behavior to be explained. The behavioral explanation is simply the most parsimonious. Early linguistic exposure produces other effects as well. For example, exposure to a specific language alters infants’ perception of specific speech sounds by 6 months of age (Kuhl et al., 1992). Although the precise mechanism by which such effects are produced remains to be determined, it seems as if, just as with the sound of the infant’s native language as well as the sound of the voices of significant others, the sounds of specific phonemes acquire behavioral functions by virtue of general principles of Pavlovian and operant learning. The role of general learning principles, however, is much easier to demonstrate in the production of speech, which sometimes involves the very same behaviors as perceiving speech. A Behavioral View of Speech Production How Do Infants Learn to Produce Speech? Typically, a distinction is made between perceiving and producing speech. Elsewhere, however, I have argued that what we normally speak of as listening is behaving (subvocally) (Schlinger, 2008a). Equating listening (to speech or music) with perceiving is consistent with the thesis in the present article; namely that when we say that someone perceives speech he or she is behaving in certain ways. Although most infants naturally progress through a series of stages of vocal sounds, and although those sounds are undoubtedly influenced by reinforcement, the role of operant learning becomes especially clear when infants begin babbling and discrete changes in their vocal output can be more easily detected. Infant babbling contains the prosodic characteristics of adult speech to which the infants have been exposed (e.g., Levitt & Aydelott Utman, 1992; Whalen, Levitt & Wang, 1991). Some researchers (Kuhl & Meltzoff, 1996) refer to this phenomenon as (vocal) imitation, although such a portrayal is not quite right. Both anecdotal and experimental observations suggest that infants in the first year of life learn to produce not just the intonation and prosody of the language that they hear but the sounds as well. In fact recent research suggests that even the “melody” of the cries of newborns’ is influenced by hearing the prosodic features of their native language as early as the third trimester of pregnancy (Mampe, Friederici, Christophe, & Wermke, 2009). Despite the admission that vocal learning depends on hearing the vocalizations of others and of oneself, language researchers acknowledge that “little is known about the processes by which change in infants’ vocalizations are induced” (Kuhl & Meltzoff, 1996, p. 2425). That does not prevent these researchers, however, from offering ad hoc cognitive explanations. For example, Kuhl and Meltzoff (1996) speculate that “infants listening to ambient language store perceptually derived representations of the speech sounds they hear which in turn serve as targets for the production of speech utterances” or that it is as though both adults and infants “have an internalized auditory-articulatory ‘map’ that specifies the relations between mouth movements and sound” (p. 2426). The problem with such explanations, as I have repeatedly pointed out, is that they are not parsimonious; that is, they require many untestable, unfalsifiable assumptions and are often just redundant descriptions of the observable evidence. More parsimonious explanations can be gleaned by comparing vocal development in human infants to that of songbirds. Vocal Learning in Infants and Songbirds: The Role of Automatic Reinforcement 159 SLP- ABA Volume 5, Issue No. 2 Researchers who investigate language development in humans and the development of songs in certain species of birds have noted many parallels (Brainard & Doupe, 2002; Doupe & Kuhl, 1999; Kuhl, 2000; 2004). For one, as already mentioned, social contingencies of reinforcement play an important role in vocal learning (Goldstein et al., 2003; 2009). Additionally, researchers agree that hearing the vocalizations of others and of oneself are necessary for vocal development in infants (Kuhl & Meltzoff, 1996) and in songbirds (Brainard & Doupe, 2002; Doupe & Kuhl, 1999). Thus, in infants and in many songbirds, immature vocal sounds are shaped into more mature sounds in large part by the feedback produced by making sounds. Although few of these scholars directly mention reinforcement or operant learning, many describe how “infants’ successive approximations of vowels would become more accurate” due to the “acoustic consequences of their own articulatory acts” (Kuhl & Meltzoff, 1996, p. 2426); or how “during sensorimotor song learning, motor circuitry is gradually shaped by performancebased feedback to produce an adaptively modified behaviour (Brainerd & Doupe, 2002, p. 355). Other researchers describe how sounds emitted by infants and songbirds “are then gradually molded to resemble adult vocalizations” (Doupe & Kuhl, 1999, p. 574). Finally, some researchers explicitly acknowledge a selection process involved in early vocal production. For example, de Boysson-Bardies, 1999 write: The vocal productions of children are thus modeled by selection processes. The phonetic forms and intonation patterns specific to the language of the child’s environment are progressively retained at the expense of forms that are not pertinent to the phonological system of this language. The process begins at birth, if not before. However, the first effects on vocal performance are delayed, particularly by the slow course of motor development. (p. 56) It is amazing that otherwise good scholars fail to either know or acknowledge that the process they are talking about is a form of selection by consequences called operant conditioning (see Skinner, 1981). In particular, infants and songbirds start out with a repertoire of immature or unrefined sounds. When the infants or songbirds hear themselves making sounds that match what they have heard from others, those sounds are automatically strengthened (i.e., reinforced) in the sense that they occur with a greater frequency relative to sounds that do not match what they have heard from others. In other words, the parity achieved when produced sounds are closest to heard sounds automatically strengthens the produced sounds (Palmer, 1996). According to some researchers, this vocal learning occurs relatively rapidly in infants and songbirds and without much in the way of external reinforcement (Doupe & Kuhl, 1999, but see Goldstein et al., 2003, 2009, emphasis added). But it does not occur in the absence of any reinforcement. Such shaping takes place as a function of automatic reinforcement, that is, reinforcement not mediated by another individual (see Vaughan & Michael, 1982). Automatic reinforcement (though not by that name) in the form of parity between self-produced auditory feedback and the sounds heard from others has also been recognized in song learning in birds (e.g., Konishi, 1965, 1985; Watanabe & Aoki, 1998). For example, according to Konishi (1985), “A bird’s use of auditory feedback in song development resembles learning by trial and error; the bird corrects errors in vocal output until it matches the intended pattern” (p. 134). By “trial and error,” Konishi means operant learning. Automatic reinforcement also plays an important role in early language acquisition (Schlinger, 1995, pp. pp. 158-160; Smith, Michael, & Sundberg, 1996; Sundberg et al., 1996), and it parsimoniously explains so-called learning without reinforcement. Automatic reinforcement is the elusive mechanism responsible for vocal learning that many language researchers (e.g., Doupe & Kuhl, 1999) are searching for, and it is right before their very eyes (or ears). Moreover, an automatic reinforcement hypothesis requires very few assumptions, is consistent with known scientific principles and is, thus, a parsimonious explanation. The only wildcard is the process by which the vocal sounds one is exposed to in his or her environment assume automatically reinforcing qualities. At this point it is not clear whether pairing with other reinforcing stimuli is necessary to establish the sounds of speech or songs as reinforcers, or whether simple exposure suffices, although the evidence suggests that mere exposure is sufficient. If so, then the question becomes how much exposure is required during the so-called sensory or perceptual learning 160 SLP- ABA Volume 5, Issue No. 2 phase. What are not helpful, however, are cognitive accounts that appeal to “perceptually derived representations of the speech sounds” (Kuhl & Meltzoff, 1996, p. 2425). Such accounts are inferred solely on the basis of behavioral observations and, moreover, are only redundant descriptions of those observations. As explanations, then, they are circular in that the only evidence of the perceptually derived representations is the fact that an individual’s vocal sounds that approximate those previously heard come to predominate in their repertoire. As I have tried to show in this paper, a behavioral account is simpler, in part because it is based on a foundation of experimentally derived principles, and, thus, does not need to appeal to inferred, hypothetical entities. Summary and Conclusions In this article I have illustrated the cognitive approach to speech perception and language acquisition by noting that although language researchers often incorporate operant or operant-like methods in their research, their interpretations of the results are problematic. Specifically, cognitively oriented language researchers often attribute the causes of speech perception and production to children themselves, or to their brains rather than to the environmental features which the researchers manipulate in their studies. Because this approach infers hypothetical constructs instead of testable physical events, it does not adhere to the principle of parsimony. Moreover, inferring hypothetical constructs leads to logical errors of reification and circular reasoning. I also attempted to show how research conducted by cognitively oriented speech and language researchers can be parsimoniously interpreted according to the experimentally established principles of behavior analysis. Furthermore, because behavior analysts demonstrate environmental variables as causes of the behaviors, their approach is inherently consistent with the principle of parsimony and is, thus, directly testable. 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G., & Arndorfer, R. E. (1993). Analysis of a simplified treatment for stuttering in children. Journal of Ap plied Behavior Analysis, 26, 53-61. Whitehurst, G. J. (1972). Production of novel and grammatical utterances by young children. Journal of Experimental Child Psychology, 13, 502-515. Whitehurst, G.J., Novak, G., and Zorn, G.A. (1972). Delayed speech studied in the home. Developmental Psychology, 7, 169-177. Whitehurst, G. J., Ironsmith, M., & Goldfein, M. (1974). Selective imitation of the passive construction through modeling. Journal of Experimental Child Psychology, 73, 288-302. Author Note I am grateful to Julie Riggott for her keen editorial eye and to Giri Hegde for his helpful comments on an earlier version of this manuscript. Author Contact Information Henry D. Schlinger, Jr. Department of Psychology California State University Los Angeles, CA 90032-8227 E-mail: [email protected] ADVERTISEMENT ADVERTISING IN BAO Journals If you wish to place an advertisement in any of our journals, you can do it by contacting us. The prices for advertising in one issue are as follows: 1/4 Page: $50.00 1/2 Page: $100.00 Full Page: $200.00 If you wish to run the same ad in multiple issues for the year, you are eligible for the following discount: 1/4 Pg.: $40 - per issue 1/2 Pg.: $75 - per issue Full Page: $150.00-per issue An additional one time layout/composition fee of $25.00 is applicable In addition to placing your ad in the journal(s) of your choice, we will place your ad on our website’s advertising section. For more information, or place an ad, contact Halina Dziewolska by phone at (215) 462-6737 or e-mail at: [email protected] 165 SLP- ABA Volume 5, Issue No. 2 Speech and language assessment: A verbal behavior analysis Barbara E. Esch, Kate B. LaLonde, and John W. Esch Abstract Speech-language assessments typically describe deficits according to form (topography), without identifying the environmental variables responsible for the occurrence (function) of a particular utterance. We analyze a database of 28 standardized speech-language assessments according to six response classes including five of Skinner’s (1957) verbal operants. We discuss the importance of including a functional analysis of speech-language skills to better inform treatment planning and target selection. Recommendations for future research are included. Keywords: speech-language, assessment, verbal behavior, functional analysis, verbal operant ____________________________________________________________________________________ Introduction As practitioners concerned with treating speech-language disorders, one of our primary goals is to accurately and efficiently determine which communication skills should be targeted for intervention. How do we know when something needs to be taught? What defines a skill deficit or a communication breakdown ? In everyday terms, a speech-language problem is signaled when a breakdown occurs in the interaction between a speaker and a listener. That is, we say that communication is successful when the outcome of an interaction is effective (i.e., functional), but when the interaction is weak and ineffective, we suspect a deficit in the repertoire of one of the communication partners. Thus, the critical aspect that defines communicative competence lies in the success of the dyad, a dynamic process comprised of functional units of discourse between a speaker and a listener, even when these roles are assumed within a single individual (e.g., Lodhi & Greer, 1989; Palmer, 1998; Skinner, 1957). Despite the fundamentally social nature of communication, assessment tools for speech-language deficits rarely take into account this requisite speaker-listener unit, nor is it routine to test for, describe, or analyze specific breakdowns in this unit. Most speech-language assessments in widespread use today evaluate response topographies (forms of responses) alone, without regard for a functional analysis of the causal variables that lead to the specific topographic features of responses. Indeed, much assessment time and energy is expended in classifying speech-language performance, not by its role within a unit of functional communication between a speaker and a listener (i.e., cause and effect), but instead only by its arbitrarily-labeled categories describing non-function based properties such as word structure (e.g., nouns, verbs, plurals), modality (expressive, receptive), relationship (e.g., antonyms/synonyms, agreement), or other inferred characteristics (e.g., ellipsis, nomination, phonological process). This focus is illustrated by ASHA’s (1993) definition of language disorder as an impairment in “comprehension and/or use of spoken, written, and/or other symbol systems. The disorder may involve (1) the form of language (phonology, morphology, and syntax), (2) the content of language (semantics), and/or (3) the function of language in communication (pragmatics) in any combination.” Although function is an element of this definition, this usage of the term refers to a linguistic feature of language (pragmatics) in contrast to Skinner’s analysis of function in which environmental variables describe (and thus, define) the contingent relatio n that accounts for each particular instance of an utterance (i.e., language). As such, linguistic descriptions are less adequate for applied work (i.e., treatments) than is Skinner’s model, which specifies the variables that evoke and strengthen verbal behavior. To be sure, a thorough topographic description of an individual’s speech-language repertoire may be a necessary component to plan an appropriate therapy program, but it is insufficient to accomplish the 166 SLP- ABA Volume 5, Issue No. 2 task because a key element of the evaluation is missing. Our job during assessment is to document not merely occurrences of wrong responses to assessment items, but also the speaker-listener environment (antecedent and consequent variables) in which the topography occurs. If a functional analysis of the speaker-listener exchange is omitted from the assessment, a critical part of language learning is at risk of being excluded from an effective intervention plan (Damico, 1993; Frost & Bondy, 2006; LaRue, Weiss, & Cable, 2008; Rowland & Schweigert, 1993; Spradlin & Siegel, 1982; Sundberg, 2008). Meaning defined by environmental context. The meaning of verbal behaviors is a function of their controlling variables (Hegde, 2008; Skinner, 1957). Speakers and listeners do not “make mistakes,” “use the wrong word,” or “fail to generalize” in the ordinary sense. A response does not occur in a vacuum, without its controlling variables or variable (Austin, 1975; Bates, 1976; Catania, 2006; Schlinger, 1995; Searle, 1969) and attempting to catalog responses without this information prevents our understanding of what a particular response “means.” It is the analysis of a response form within a context defined by antecedent and consequent variables that allows us to determine whether the response is correct or not. For example, the cause-effect context in which a thirsty person asks for water please is different than that in which he or she is not thirsty but nevertheless emits water in responding to a teacher’s instructions to repeat after me: “water.” The point is the same regardless of topographies; saying water in New York or agua in Costa Rica or Wasser in Germany does not “mean” the same thing when one wants water as it does when one is responding to say “water” or repita “agua” or bitte wiederhole “Wasser.” Topography is interesting only in terms of the functional context in which it occurs. The point applies whether considering a single topography (e.g., water, agua, Wasser) or equivalent forms (synonyms). Whether assessing or treating speech-language skills, a knowledgeable clinician will recognize that the conditions that evoke pickle and cucumber are not at all the same as those stimuli that evoke pickle and predicament. It is not the words that mean the same thing; antecedent and consequent relations (e.g., request vs. repeat contingencies) are what explain the occurrence of these forms. That is, forms may be interchangeable only to the extent that they share the same controlling variables. Thus, “meaning” is topography within a contingent relation of controlling variables and it is this contingent arrangement that establishes function (i.e., mean ing). Without assessing the controlling variables (motivation, discriminative stimuli, consequent stimuli) that evoke and strengthen or weaken speech-language responses, we may fail to identify appropriate functional (cause-effect) relations by which defective forms (e.g., grammatical errors) of a disorder should be remediated. Evaluations that result in effective intervention plans include an examination of the reasons (controlling variables) that an individual’s verbal environment would occasion or maintain particular speech-language topographies (right or wrong) in the first place. We must account for these occurrences by determining the conditions that evoke and maintain them, to adequately prescribe a treatment program that will eliminate, modify, or otherwise resolve these errors. In sum, a complete speech-language account (Skinner, 1957) would describe not only the form of a speaker’s response but it would also explain the function of interactions between a speaker and a listener, resulting in a detailed description of response errors in terms of their topographies (specific words) and the environmental contexts (antecedent/consequent stimuli) in which those topographical errors occur. This would provide both the description (topography) and the explanation (function) for any given response. Such an account is essential for planning and carrying out effective interventions, whether they involve simple or complex treatments. Without such information, we risk embarking on an incomplete or poorly articulated treatment program that produces or maintains errors (i.e., poor stimulus control over correct responses), resulting in gaps (e.g., splinter skills) in the overall verbal repertoire (see Baker, LeBlanc, & Raetz, 2008; Greer & Ross, 2008). Treatment Efficacy A perplexing discrepancy currently exists with respect to assessment and treatment of speechlanguage disorders. On the one hand, standardized assessment tools that dominate in the field of speech- 167 SLP- ABA Volume 5, Issue No. 2 language pathology are based on, and result in, a linguistic description of speech-language, yet, at best, these assessments can only weakly inform treatment because a linguistic approach to treatment does not exist (Hegde & Maul, 2006). It is true that not all speech pathologists rely solely on standardized tools to inform their treatments. However, whether they use standardized tests alone or they supplement them with other information (e.g., language samples), the analysis of skills for the purpose of diagnosis and treatment planning is linguistically based. This is handicapping because, despite linguistic information from the assessment, the therapist lacks the functional analysis of verbal behavior needed to effect behavior change, which is the sole aim of therapy. Moreover, he or she must look elsewhere (i.e., applied behavior analysis) for effective teaching tools (e.g., Cooper, Heron, & Heward, 2007; Hegde, 1998; Miltenberger, 2001) and formats (e.g., Lovaas & Smith, 2003) that can support clinical intervention. By contrast, a functional (behavioral) approach to speech-language has already been described for both assessment (e.g., Carr & Durand, 1985; Duker, 1999; Frost & Bondy, 2002; Greer & Ross, 2008; Hart & Rogers-Warren, 1978; Lerman et al., 2005; Spradlin, 1963; Sundberg, 2008; Sundberg & Partington, 1998) and for treatment (see Hegde, 1998, Ogletree & Oren, 2001, and Sautter & LeBlanc, 2006 for reviews). Despite this, it is only speech-language treatment that seems to have been influenced by behavior analysis and its technology (e.g., Bourgeois, 1992; Kouri, 2005; Rvachew, 1994) whereas assessment of these disorders remains firmly linguistically based on tools (see Directory, American Speech-Language-Hearing Association, ASHA, 2009) that do not include or provide for an analysis of environmental variables that control the speech-language performances assessed. It is perhaps this problem referred to by proponents of informal (i.e., criterion-referenced) assessments (Notari & Bricker, 1990; Romanczyk, Lockshin, & Matey, 2001) for children with a diagnosis of Autism Spectrum Disorder (ASD). These advocates argue that, for this population at least, standardized assessments typically do not identify appropriate curricular targets. Although focused on the needs of individuals with ASD, these and other discussions (National Autism Center, 2009) emphasize the issue of treatment efficacy for all individuals receiving speech-language intervention and the need to administer assessments that are comprehensive enough to inform treatment. The Purpose of Assessment Speech-language assessment is conducted for many reasons. It can provide diagnostic labels (e.g., specific language impairment, apraxia of speech, aphasia) and help determine therapy progress. It can also support documentation required by agencies, such as performance comparisons (i.e., normreferenced data) for Individualized Educational Plans in schools, and status updates for reimbursement purposes in medical and clinical settings. But by far, one of the most important purposes of an assessment tool is to provide adequate information to plan an effective intervention that fits into a sequenced curriculum of skills. As mentioned earlier, most standardized assessment tools used by SLPs are based theoretically on a linguistic analysis of language for which no corresponding treatment methods are available. This “conceptual inconsistency” (Hegde & Maul, 2006) results from several historical influences on the development of the profession’s theoretical base and may explain the prominence (Novak & Pelaez, 2004) of diagnostic labels (e.g., apraxia, auditory processing disorder) in terms of hypothetical constructs in lieu of function-based explanations of behavior. Duchan (2008) traces the current conceptual perspective in speech pathology from an emphasis on psychological processing (1945 to 1965) to linguistics (1965 to 1975) and, finally, to pragmatics (1975 to 2000) at which time “we reconsidered and reframed language in light of its communicative, linguistic, cultural, and everyday-life contexts” (p. 2). It is unclear what is meant by “everyday-life contexts,” but a functional (cause-effect) analysis of language may be the goal. Much of what is described in this historical review hints at the need to address behavioral function (see also Prizant & Duchan, 1981) and there is a tangential nod to behavior analysis evident in Duchan’s program descriptions that include sabotage techniques (i.e., motivating operations; Laraway, Snycerski, Michael, & Poling, 2003) and response intents (i.e., mand, tact, intraverbal; Skinner 1957). Despite this, the descriptive focus, including that widely available (e.g., Pinker, 1994) to general consumers interested in language development, remains clearly non-behavioral 168 SLP- ABA Volume 5, Issue No. 2 (e.g., psycholinguistic skills, linguistic relationships). What has evolved, and permeates the field of speech pathology, appears to be largely a non-behavioral view of language learning in which a functional analysis for many professionals may not mean a causal, explanatory analysis of verbal behavior in terms of the environmental stimuli that evoke and maintain it but, rather, may resonate more as a description of the “use of language.” This can impede prescription and remediation efforts by failing to provide a full account of speech-language performance: speaker-listener interactions comprised of not only topographic/structural descriptions but also of functional (i.e., causal) explanations for the occurrence of those topographies. Challenges to Resolve A number of issues present both assessment and clinical application challenges for speech pathologists and others responsible for teaching speech-language skills. We propose that solutions are available to help resolve these issues by applying a behavioral analysis to the assessment process initially and, later, throughout treatment. Our discussion of these concerns follows. 1. Receptive-Expressive Dichotomy Speech-language and its assessment is typically described as consisting of two categories, receptive and expressive. Accordingly, treatment plans are likely to channel the therapeutic focus into this same dichotomy. As a result, speaker and listener repertoires may be regarded as simply two halves of a common cognitive process in which words are “understood” in one modality and “used” in another. Instead of considering language as performance (i.e., behavior), this traditional view of language implies that a language entity exists structurally as a type of cognitive holding tank from which appropriate responses (i.e., “meaning”) are chosen to fit a particular communicative situation. The notion is that speakers toggle between selecting a word and using it. It is significant, however, that we do not appeal to a similar cognitive account to explain nonverbal behaviors, such as scratching an itch or scrubbing a pot. No one would assert that, when the mosquito bites, we select a scratch from a mental reservoir of available muscle actions. We would be satisfied to contend that the itchiness occurred, we scratched it, and the itch went away. In contrast to linguistic explanations of language, a behavioral view posits that we would not “use” a word, water for example, any more than we would “use a reach” (Skinner, 1957, p. 7) to obtain the water itself. Instead, antecedent and consequent conditions related to water are sufficient to evoke either response, whether a nonverbal reach for water or a verbal water (Hegde & Maul, 2006). Nothing is gained by inserting a hypothetical construct (receptive or expressive “use”) into an explanation of why the response occurred. We still have to account for each instance of the proposed use (Sundberg & Michael, 2001). This requires identifying the response of interest as part of a unit of motivational variables, prompts, instructions, and consequences. Instead of residing at-the-ready in a sort of cognitive container, speech-language skills are more usefully characterized as different repertoires based on separate functional relations between antecedent and consequent conditions (Hegde & Maul, 2006; Schlinger, 1995; Sundberg & Michael, 2001). Appealing to hypothetical constructs to explain instances of verbal behavior can obscure a clinician’s efforts to pinpoint errors during assessment and to target a coordinated sequence of skills for remediation. Consider a situation in which a child does well on a receptive test of verb tense but fails verb items on an expressive test (e.g., CELF-4; Semel, Wiig, & Secord, 2003). Is the problem with the speaker repertoire (expressive) in general or with verb tense specifically? Should treatment consist of repeating verb tense forms while looking at pictures (e.g., the boy is running) or should it provide practice in completing sentences (e.g., Bob is walking but Reggie is . . .), with pictures or without? What if the learner can label pictures with progressive verb forms (e.g., TWF-2; German, 2000), but cannot complete sentences with correct verb forms, or changes 169 SLP- ABA Volume 5, Issue No. 2 verb tense when asked to repeat sentences (e.g., CELF-4; also CELF-P, Wiig, Secord, & Semel, 2004; TOLD-P:3, Newcomer & Hammill, 1988), a task that essentially tests echoic skills? Is this a problem of verb tense, sentence completion, or poor repetition (i.e., echoic)? What about the learner who can say rhyming words but cannot point to them (e.g., PLS-4; Zimmerman, Steiner, & Pond, 2002)? Is the problem receptive or does it indicate a poor (possibly covert) echoic repertoire (i.e., “expressive”)? How are we to interpret results of a test that shows a child can point to a puppy in response to which one is little but cannot tell you the opposite of big? Should you work on adjectives, opposites, or general expressive skills? These situations exemplify the difficulty in determining intervention targets from assessments where skills are not explained functionally (i.e., by their controlling variables) but, instead, they are defined linguistically and categorized topographically as either receptive or expressive. 2. Mismatch Between Assessment Focus and Real-World Contingencies Most speech-language tests in wide use today are standardized instruments (ASHA, 2009) that provide information about skills solely according to linguistic parameters, described earlier as topographic responses. However, the speech-language behavior emitted by an individual does not exist in a topography-only sense, absent its effect on a listener (Skinner, 1957) and, in the real world, topographic errors (thoup for soup) are disregarded (Hart & RogersWarren, 1978) unless their form is too deviant (e.g., my doggy runded away). Topographies become functional entities (i.e., meaningful) only when they occur in a dynamic environment consisting of at least one speaker and one listener. We cannot know what a speaker means if we hear him or her say shoe merely on the basis of the topography (word) itself. We need access to the speaker’s reasons, a description of the conditions that evoked such a response (Hegde, 2008). Functional speech-language behavior is evoked and strengthened in a unit in which antecedent and consequent stimuli occur in temporal proximity to an instance of a speaker’s topographic behavior and combine to become functional communication (see Sautter & LeBlanc, 2006). Therefore, its description, to be useful for treatment planning, must involve more than just a description of topography. Instead, we need to describe speech-language behavior more functionally (e.g., Baker et al., 2008; Greer & Ross, 2008; Koegel & Koegel, 1995) with resulting evaluation tools (e.g., Sundberg, 2008; Partington & Sundberg, 1998) that take this functional unit into account. 3. Treatment Interference Due to Problem Behavior We have often heard the sentiment expressed by clinicians and others that “I can’t work with this person until his (or her) behavior is fixed.” It is true that interfering behavior is a problem, yet it need not preclude our assessment and teaching efforts. A good first step is to ask “if he were speaking English (or any language) right now, instead of crying, hitting, running away, what would he be saying?” Through functional analysis (Iwata, Dorsey, Slifer, Bauman, & Richman, 1994), it is possible to identify and address weak speech-language repertoires that are functioning as problem behavior. Functions have been identified that indicate problem behavior, although not recognizable as true language in form, is indeed functioning as language to gain access to (i.e., request) attention, tangibles, or escape from task demands (e.g., Dwyer-Moore & Dixon, 2007; Kodak, Northup, & Kelley, 2007). For learners with weak communication skills disguised as problem behavior, listener skills are often the initial focus of therapy (i.e., compliance training) because these skills were the weakest (and thus most salient) during assessment. Although listener skills are critically important in the overall speech-language repertoire, focusing initial treatment on those skills may be unproductive for learners with interfering behavior problems. From a functional standpoint, this is because the consequences for listener responses do not directly benefit the speaker 170 SLP- ABA Volume 5, Issue No. 2 (Skinner, 1957). Learners who already find little to compel them to engage in treatment are unlikely to be motivated by generalized social reinforcers (i.e., praise) when they can emit easier responses (e.g., hitting) that readily produce consequences of greater value to them. For the learner with a history of failure for speech-language attempts, mand (i.e., request) assessment and training is a good first choice (Esch, 2009; Koegel & Koegel, 1995) because the consequences that maintain mand behavior are specific and are of direct benefit (i.e., you get what you ask for). The key issue is to train responses that are equivalent in function (e.g., access to attention) but yet are more socially acceptable in form (e.g., asking instead of hitting). Typically developing children develop a strong repertoire of mands before other verbal operants (Bijou & Baer, 1965; Novak, 1996) and, like any other learner, when this skill set is defective, it is not unusual to see problem behaviors arise that fill the functional vacuum. Therefore, the task of assessment is to identify not only inappropriate response form, but its function. Without determining function, eliminating an offensive form alone is unlikely to succeed. Through assessment of verbal functions, the therapist can identify appropriate mands to teach in order to provide the learner, child or adult, with speech-language responses that are adaptive in the natural environment, regardless of diagnosis (e.g., ASD, traumatic brain injury), disability label (e.g., developmental language impairment, aphasia, apraxia of speech), or educational setting (e.g., home, school, hospital, clinic). 4. Identifying and Sequencing Intervention Targets Assessment should lead to a plan for intervention, a prescriptive list of targets to be acquired (LeBlanc, Dillon, & Sautter, 2009). When assessments identify deficits in nonfunctional, topographic terms alone (e.g., derivational adjectives, inflection verbs), it can be difficult to pinpoint specific speech-language responses that would be manageable therapy targets or to determine how they fit together as part of a competent verbal repertoire. What should we teach first – nouns, opposites, plurals, or colors? Should we work to resolve word-finding problems before number repetition or relational vocabulary? Because none of us has access to a learner’s perceptions or cognitions (Schlinger, 1995; see also, Schlinger, this issue), targets identified in linguistic terms are not easily modifiable until they are re-interpreted as a measurable, observable set of responses, defined as part of a functional verbal unit comprised of antecedent and consequent stimuli. Given these more concrete criteria, it is easy to see how topographic descriptions alone do not resolve our diagnostic task. Functions of verbal behavior. No doubt most readers of this journal are familiar with Skinner’s (1957) analysis of verbal behavior, which provides a useful theoretical framework for assessing, and thus treating, speech-language behavior in terms of the environmental variables that control verbal responses (see also Greer & Ross, 2008; Hegde, this issue; Sundberg, 2008; Sundberg & Partington, 1998). Table 1 presents five of these verbal operants that are most relevant to our discussion. In brief, consider the conditions under which we might emit the response cookie. When hungry, we might ask for cookie. We could say cookie! in response to seeing, smelling, or tasting one even if we are not hungry. Given the instruction say ‘cookie’, we may emit the required repetition. Also, we could likely respond cookie to one of many verbal stimuli related to the topic of cookies (e.g., what did your mom bake, what does c-o-o-k-i-e spell). Finally, we might read cookie if we saw it written on the Keebler box. The foregoing examples are identified as mand, tact, echoic, intraverbal, and textual operants, respectively, and, in each instance, the form of the response is the same, yet the environmental conditions (antecedent/consequent stimuli) in which each response would likely be emitted are not at all equivalent. When assessments provide this level of speech-language information, a more effective intervention plan can be designed, one that addresses not only response topographies but 171 SLP- ABA Volume 5, Issue No. 2 response function as well, thus ensuring a more integrated language learning experience for those we teach. Table 1. Descriptions of five elementary verbal operants (Skinner, 1957) Verbal Operant Antecedent events that evoke the operant Response Consequent events that strengthen the operant Mand Motivating conditions (e.g., wants toy airplane) Asking (e.g., Airplane) Specified by the mand (e.g., Gets toy airplane) Echoic Verbal stimulus (vocal) (e.g., “Say ‘airplane’”) Repeating (e.g., Airplane) Generalized social reinforcers (e.g., “Right!”) Tact Nonverbal stimulus (e.g., Airplane flies overhead) (e.g., Look Mommy, Airplane!) (e.g., Mom: “Wow! That’s really big!”) (e.g., “Did you arrive by train?”) Verbal stimulus (any) Conversation (e.g., No, airplane) Generalized social reinforcers (e.g., “Oh, how was the flight?”) Verbal stimulus (textual) (e.g., Word: AIRPLANE) Reading (e.g., Airplane) Generalized social reinforcers (e.g., “Good reading!”) Intraverbal Textual Labeling Generalized social reinforcers NOTE: Functions that may involve complex language behavior (e.g., problem solving, remembering, joint control, emergent relations) are outside the scope of this paper. Readers interested in these topics are referred to Donahoe and Palmer (1994), Lowenkron (2006), or Rehfeldt and Barnes-Holmes (2009). Sequential targets. Assessments need to do more than just identify what needs to be taught. Intervention targets also need to be sequenced in such a way that the learner’s new communication skills achieve success in his or her verbal community as quickly as possible (Greer & Ross, 2008). Teaching targets sequenced according to a functional analysis of verbal behavior may be more efficient than following traditionally defined sequences (i.e., receptive before expressive) (Miguel & Petursdottir, 2009). For example, Williams and Greer (1993) demonstrated that, when targets were defined in terms of their verbal function, children learned functional and spontaneous speech, whereas, when linguistic targets were taught, the children learned fewer forms and functions. This study shows that when the variables that control a speech-language target response are identified, they can be used, modified, or otherwise brought to bear on the response of interest to help a therapist effect change in the learner’s verbal behavior to ultimately become a more competent speaker. As we shall see in the next section (see Error Analysis below), this is a powerful tool for therapists. Sometimes the controlling variables for certain intervention targets are inside the learner’s body and thus they are inaccessible to the clinician. Response targets like these, often called feelings (e.g., tired, happy, sad, angry, sick), are difficult to teach because, as clinicians, we cannot verify the presence/absence of the stimuli that evoke them. Yet these and other private events (Schlinger & Poling, 1998; Skinner, 1957) are commonly tested in speech-language assessments (e.g., PLS-4; ROWPVT, Brownell, 2000; TOLD-P:3) and are often selected as targets to teach labeling non-verbal stimuli (i.e., tact) to children whose tact repertoires are weak even for stimuli that are outside the skin and thus are verifiable by teacher and learner alike (e.g., book, wagon, pizza). Because of this, assessments that identify controlling variables for potential 172 SLP- ABA Volume 5, Issue No. 2 intervention targets (e.g., Sundberg, 2008) have the advantage of pointing clinicians toward appropriate targets and, at the same time, focusing their efforts away from targets that may seem important but that are premature in the developmental-functional curriculum. 5. Error analysis The purpose of speech-language assessment is to identify response errors in the learner’s verbal repertoire so treatment can be provided that will eliminate these errors in the day-to-day communication environment and replace them with more adequate responses. As discussed, a careful analysis of the controlling relations for speech-language responses can provide valuable information for treatment planning. The value of an error. Error responses are instructive for clinicians because they tell us precisely what variables control the extant incorrect response. An analysis of these errors allows us to thereby establish correct responses and to eliminate stimuli as prompts (i.e., multiple control) that are extraneous, but currently required, to evoke these responses (Sundberg & Michael, 2001). For example, a learner may indeed be able to correctly answer How many feet does a duck have when visiting the duck pond at the park but may not be able to emit the same correct response on the ride home when the visual stimulus (i.e., the duck) is absent. By cataloging the conditions in which a desired response does and does not occur, we have the information we need to write intervention plans to transfer control from the current evocative variables to those that should evoke and maintain correct responding. Functional independence of operants and stimulus control transfer. Whereas a verbally competent speaker may readily tact after learning to mand, or to respond intraverbally after learning to point to an item, this seemingly automatic transfer of function does not occur easily for individuals with speech-language impairment. For example, in a study of tact, mand, and intraverbal responding (Sundberg, San Juan, Dawdy, & Argüelles, 1990), individuals with traumatic brain injury demonstrated hierarchies of acquisition, showing that verbal functions (e.g., tact, mand) could be acquired from echoic or textual (i.e., letters) control but that stimulus control transfer (Catania, 1998) from one function to another did not occur without direct training. A growing body of literature in error analysis has shown the functional independence of many language-related responses (e.g., Braam & Poling, 1983; Hall & Sundberg, 1987; Lamarre & Holland, 1985; Luciano, 1986; Miguel, Petursdottir, Carr, & Michael, 2008; Partington & Bailey, 1993; Petursdottir, Carr, Lechago, & Almason, 2008; Sidman, 1971; Sigafoos, Doss, & Reichle, 1989; Twyman, 1995; Watkins, Pack-Teixeira, & Howard, 1989) and stimulus control transfer has been reported for several verbal functions. Sweeney-Kerwin, Carbone, O’Brien, Zecchin, and Janecky (2007) transferred control of mand responses by children diagnosed with ASD from nonverbal stimuli (i.e., tact) to appropriate motivating conditions. In another study of children with ASD, Goldsmith, LeBlanc, and Sautter (2006) reported successful transfer of stimulus control to bring tact responses under intraverbal control. A study by Lerman et al. (2005) illustrates particularly well the value of analyzing language responses by their controlling variables. In this study, a child could tact baby but could not mand baby nor emit any baby-related intraverbal responses. The specificity of this type of information, by verbal function, clearly pinpoints treatment goals (e.g., teach mand and intraverbal responses for the same topography as that acquired under tact control). Clinical competence with stimulus control transfer is particularly useful in identifying appropriate intraverbal targets and in providing treatment that avoids inducing errors with this complex repertoire. Whereas the conditions that might evoke a single mand, tact, or echoic response are fairly straightforward, the variables controlling any particular intraverbal response 173 SLP- ABA Volume 5, Issue No. 2 can be numerous. For instance, a mand requires only sufficient motivating conditions; the tact is evoked by a particular nonverbal stimulus; and an echoic, in general terms, is simply a repetition of an auditory model. On the other hand, a competent speaker has an intraverbal repertoire in which a single response is under the control of tens, perhaps hundreds, of antecedent stimuli that evoke it. For example, under appropriate conditions, we could easily emit the intraverbal response salsa to stimuli such as what’s tortilla dip called, let’s chop tomatoes to make some. . ., what dance class are you taking, and any number of other salsa-related questions. But learners with weak speech-language repertoires will be challenged by any one of these stimuli and, as we have suggested, simply teaching a selection, tact, echoic, or mand response is unlikely to result in an extensive salsa repertoire. A behavioral interpretation of the findings discussed above dissuades us from cognitive explanations of deficits identified through our assessments. Because a learner can point to a dog when asked, but cannot name a dog when he sees one is not well explained by saying that he does not yet have the concept of dog. Instead, we can more profitably turn our attention to the variables that evoke various dog responses to plan and carry out an effective treatment program. We cannot blame learners or their disability for error responses when we have yet to arrange appropriate stimulus conditions that will evoke and strengthen more accurate responses. Indeed, clinicians who understand how to assess error responses in terms of their controlling variables have a distinct advantage in helping learners increase their speech-language skills (Sundberg & Michael, 2001) by strengthening appropriate stimulus conditions under which particular target responses occur. Functional Assessment in Speech-Language Pathology A few models (partial or comprehensive) are available for functional assessment of speechlanguage disorders (e.g., Baker et al., 2008; Carr & Durand, 1985; Grow, Kelley, Roane, & Shillingsburg, 2008; Lerman et al., 2005; Partington & Sundberg, 1998; Sundberg, 2008; note: SLPs interested in functional assessment related to feeding disorders are referred to Piazza & Roane, 2009) and researchers have called for increased attention to environmental variables for analysis of communication disorders (e.g., Hyter, 2007; Roth & Spekman, 1984). However, in general, SLPs largely rely on standardized, linguistic-based assessment tools to provide diagnostic information, which are unlikely to inform or adequately support efforts to design appropriate and effective intervention programs. It is perhaps not surprising, then, that speech-language pathologists often turn to criterion-referenced tests to develop appropriate intervention targets, although, absent analyses of causal variables, such informal measures arguably offer no advantage over their standardized counterparts in terms of providing a behavioral analysis of language performances, which we maintain is essential for effective treatment planning. Database of Speech-Language Tests As a first step in bridging this gap, it would be helpful to have a “translation” of existing assessment instruments, reinterpreted according to the verbal functions that are represented by their test items. To that end, we examined a group of speech-language tests (Tables 2 through 7) designed to diagnose aphasia, apraxia of speech, articulation and phonological disorders, and language disorders (expressive, receptive, or both). Assessments for other speech-language disorders such as fluency (i.e., stuttering), voice quality, and dysphagia (swallowing disorders) were excluded from the database. The assessment database consists of 28 standardized speech-language tests that were selected from among those commonly used at a university-based speech and language clinic. The clinic is associated with a graduate program for SLP, which is accredited by ASHA’s Council on Academic Accreditation in Audiology and Speech-Language Pathology. Tests are administered to individuals referred for diagnostic purposes or, in the case of established clients, the tests are given to document progress toward therapeutic goals. 174 SLP- ABA Volume 5, Issue No. 2 The database lists the probable controlling variables for responses required in each test or subtest. For some test items, it is likely that multiple stimuli must be self-generated to emit a “correct” response (e.g., self-echoics). Thus, a more complex analysis may be needed in which additional variables are considered (e.g., joint control, Lowenkron, 2006; emergent relations, Sidman, 1994; see also BarnesHolmes, Barnes-Holmes, & Cullinan, 2000; autoclitics, Skinner, 1957). Nevertheless, a beginning analysis is offered, listing the test item’s probable controlling variables for 5 of Skinner’s verbal operants mand, echoic, tact, intraverbal, and textual, and for the nonverbal operant involving listener relations commonly referred to as receptive language. Procedures Each test (or subtest) was coded according to the verbal operant represented by the inherent or implied antecedent conditions prescribed by the test and by any other information available with respect to the functional unit represented by each test item. Antecedent conditions included examiner’s instructions (e.g., point to, say what I say, tell me about), materials, allowed prompts, and actual or implied motivating operations (Laraway et al., 2003; Michael, 1982, 2004) to evoke appropriate responses. In some assessments, allowed prompts changed the operant being tested by providing additional stimuli that could exert control over the response. Tables 2 through 7 specify these situations (when they could be identified by the test protocol) with the letter P (prompt) under the appropriate operant column, indicating a potential change in, or addition to, the basic operant being tested. Other factors that informed the coding procedure included controlling variables that were only implied, but not directly tested, due to the nature of the test (i.e., informant assessments, see Table 5). Such indirect assessments are so designated in the Comments column. Each test or component subtest was coded twice, once by the first author, a board certified behavior analyst and speech-language pathologist, and again by the second author, a graduate-level speech-language pathology student with an undergraduate degree in behavior analysis. In the case of disagreement, an independent behavior analyst reviewed items until agreement was reached. Code Definitions Test items were coded according to Skinner’s (1957) five basic verbal operants (mand, tact, intraverbal, echoic, textual) or, in the case of nonverbal operants, as receptive items. To be precise, the test items themselves were not operants, but they were coded as such because of the type of functional unit that would exist if a correct response to the test item occurred and was reinforced. It should be noted, however, that in many general testing situations, reinforcement is specifically proscribed (presumably to maintain test integrity). For this reason, no such functions are assumed to be established through the testing procedure with the assessments in our database. For the examiner-practitioner, advantages of withholding reinforcement during assessment should be carefully evaluated as some studies have shown improved test performance under reinforcement, compared to non-reinforcement conditions (e.g., Edlund, 1972; Koegel et al., 1997). Mand. A test item was coded mand (M) if there was evidence that the item evaluated responses under the control of a motivating operation or if a consequence, provided or implied, was responsespecific (e.g., child says cookie and gets cookie). Echoic. Items coded echoic (E) presented verbal stimuli for which a correct response would be verbal with point-to-point correspondence. For example, a correct echoic response to the instruction “Say ‘what’s your name’” would be what’s your name. Tact. A tact (T) code designated items in which a non-verbal stimulus (e.g., picture, object) was presented to evoke a verbal response. For example, an item would be coded T if it instructed the examiner to show a picture of a house, with house being the correct response. Note, however, that in both assessment and instructional situations, it is a frequent practice to add the question what’s this when 175 SLP- ABA Volume 5, Issue No. 2 presenting pictures or objects to test “labels.” In such cases, a response is more accurately described as being under both tact (house picture) and intraverbal (what’s this) stimulus control. Items were also coded T if a nonverbal stimulus was given to evoke verbal responses regarding attributes such as stimulus feature, function, or class (e.g., a correct answer would be bounce or beach instead of ball). Intraverbal. A test item was coded intraverbal (IV) if it contained a verbal stimulus to evoke a verbal response that did not match (repeat) the examiner’s model. For example, if the verbal stimulus was what’s your name, a correct response under the control of intraverbal contingencies might be Riley. Items were also coded IV if a verbal stimulus was presented to evoke verbal responses regarding stimulus attributes such as feature, function, or class (e.g., wheel, ride in, or vehicle instead of car). Textual. A test item was coded textual (Tx) if the assessment instructed the examiner to present a written stimulus and a correct response required reacting to the written material verbally (i.e., reading). Items were further designated intraverbal (IV) if reading comprehension was required. Receptive. Items asking the examiner to present an instruction, in which a correct response would be nonverbal, were coded as receptive (R). Examples of R-coded items are point to cup, give me the pencil, and show me jumping. Items were also coded R if a conditional discrimination was required regarding stimulus attributes (e.g., point to the one that has a tail instead of point to dog). Note that other operants are implicated in conditional discriminations and these are designated in the Tables (e.g., echoic, tact). Finally, items that may have required multiple controlling variables are so designated with the probable operants marked within parentheses. Following the database (Tables 2-7 below), we present a summary in which we discuss patterns found in our analysis along with implications for future work on this topic. Table 2, Next Page! 176 SLP- ABA Volume 5, Issue No. 2 Table 2. Aphasia Tests 177 SLP- ABA Volume 5, Issue No. 2 Table 3. Apraxia Tests 178 SLP- ABA Volume 5, Issue No. 2 Table 4. Articulation/Phonology Tests 179 SLP- ABA Volume 5, Issue No. 2 Table 5. Receptive-Expressive Language Tests 180 SLP- ABA Volume 5, Issue No. 2 Table 6. Expressive Language Tests 181 SLP- ABA Volume 5, Issue No. 2 Table 7. Receptive Language Tests Results, Discussion, and Considerations for the Future Information from the speech-language assessment database points to several issues of interest for future investigations. First, analysis of the database revealed a striking omission in traditional speech-language tests. The mand function, widely regarded as the earliest verbal operant established (Bijou & Baer, 1965; Schlinger, 1995; Sundberg, 2008) and of greatest benefit to speakers (Skinner, 1957), was assessed in only two of the 28 database tests (PLS-4; REEL-3, Bzoch, League, & Brown, 2003). Despite their inclusion, the mand function in these tests was only indirectly evaluated (i.e., informant report, such as parent or caregiver responses, was either required or allowed). This means that relevant motivating conditions for the occurrence of mands were not directly arranged or evaluated for their evocative effects. Moreover, it is of particular concern that mand contingencies were absent from the three assessments for aphasia, an acquired neurological disorder that often is profoundly damaging to speechlanguage repertoires. It would seem that, of all the verbal functions potentially impaired in aphasia, the mand would be of foremost importance to evaluate and, if weak, to re-establish quickly. Collectively, aphasia tests in the database represent a total of 475 response opportunities for persons with aphasia, yet the tests contained no mand contingencies to evaluate this critically important repertoire for these individuals. Behavioral researchers have begun to offer alternative (i.e., non-traditional) models for the description of aphasia deficits (Baker et al., 2008), but functional evaluation of this critical skill in the repertoires of actual individuals appears unaddressed in this population. Next, analysis of the assessment database brought the importance of stimulus control into clearer focus on at least two issues related to its identification. Unlike assessments in which controlling stimuli are specified by the test items (e.g., tact, mand), traditional speech-language tests may unintentionally require multiple stimulus control for correct responding. At other times, they may inadvertently provide multiple stimuli (i.e., prompts) when it is undesirable to do so. As a result, test items may be harder or easier than they are meant to be, obscuring the repertoire purportedly being tested. That is, learners would 182 SLP- ABA Volume 5, Issue No. 2 be disadvantaged if they do not have the requisite learning history to respond correctly when doing so requires control by more than one independent variable or when, conversely, multiple stimuli must be in place for the learner to respond correctly to items intended to test a single function. Several assessments in the database illustrated this issue in which it seemed that several stimuli must, or could, converge to evoke a correct response, thereby risking confounded test results. For example, some assessments (e.g., TOLD-P:3) require the learner to listen to a word and then repeat only part of it (e.g., say ‘baseball’ without saying ‘base’). Although this clearly evaluates echoic control, other repertoires may be required (e.g., intraverbal, autoclitic; Schlinger, 2008; Skinner, 1957), particularly since the correct response must necessarily omit part of the echoic model, as a self-editing response. Multiple control was also implicated in situations where instructions to the learner seemed ambiguous (e.g., prompting a pointing response with tell me; PLS-4). In this case, although a pointing response is presumably sufficient to be scored as correct, a learner who not only points but also responds verbally (i.e., it’s that one!) may have a more sophisticated repertoire than a learner who only points to the answer. If so, this information would be important for treatment planning. Multiple control required for correct responding was also evident in assessment items where the actual function being evaluated changed as a result of prompts allowed during correction procedures. For example, the Goldman-Fristoe Test of Articulation (GFTA-2; Goldman & Fristoe, 2000) consists of asking what’s this while showing pictures one at a time. Each response is then evaluated for point-to-point correspondence with the phonemic elements of the (unspoken) model. As such, this test evaluates a tact repertoire (more precisely, a tact-intraverbal repertoire). However, if no response occurs, an echoic prompt is allowed (e.g., say ‘house’). Thus, the task changes from one requiring tact/intraverbal control to one that requires echoiconly control. However, because the pictures are presumably still present, the clinician cannot be certain whether there is partial tact control over an echoic response, should one occur. These examples illustrate the difficulty in trying to assess speech-language skills with assessments that specify only topography, and not contingencies, required for a correct response. That is, individuals without the requisite learning history or those with obvious impairment (e.g., aphasia) may have only part of the skills necessary to perform well on these assessments and, without a clear identification of the variables required for correct responding, the learner’s repertoire may appear more or less deficient. Therefore, assessments to identify therapy intervention targets need to clearly identify (1) the stimulus control for various operants that define a competent speech-language repertoire and (2) the foundational, cumulative repertoires that may need to be in place (e.g., tact, listener) to support more complex responding (e.g., intraverbal). This explication should take into consideration recent research and supporting literature regarding complex speech-language skills such as naming and categorization (e.g., Miguel et al., 2008; Petursdottir et al., 2008), equivalence (Sidman, 1994), and other derived relations (e.g., Rosales & Rehfeldt, 2007). Speech-language assessments yielding a functional hierarchy of skill deficits have the advantage of being more prescriptive for subsequent intervention than are those that yield structural-only descriptions of errors (Baker et al., 2008; Lerman et al., 2005; Sundberg et al., 1990). This is because the independent variables governing, and thus crucial to, behavior change are not typically assessed, described, or otherwise addressed in traditional speech-language assessments (although there is evidence of emerging interest in the contextual communication environment; e.g., Hyter, 2007). One recently published assessment of verbal functions and related language skills is the Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP, Sundberg, 2008), which provides clinicians with a hierarchy of 170 skills developmentally referenced from ages 0 – 48 months. Skills are balanced across the verbal functions (e.g., mand, tact, intraverbal, echoic) and related areas (e.g., social skills, linguistic skills, reading) in order to avoid the rote responding that can occur when out-of-sequence skills are taught (e.g., intraverbal) without having first established the requisite supporting functions, such as tact and listener repertoires (also see Greer & Ross, 2008). To address behaviors that may interfere with skill acquisition, an additional component test, the VB-MAPP Barriers Assessment, identifies 24 potential 183 SLP- ABA Volume 5, Issue No. 2 learning barriers to which environmental (i.e., behavioral) solutions can be applied in order to maximize instructional efficiency. Future research needs to establish the clinical efficacy of the VB-MAPP and other function-based speech-language assessments (e.g., Partington & Sundberg, 1998) as they become available. In the meantime, assessments of this sort offer immediate clinical benefit over non-functional speech-language tests because they allow clinicians to identify speaker-listener deficits according to developmental norms in a curricular sequence and, at the same time, they pinpoint the environmental variables that currently control these responses errors. By identifying the variables of which errors are a function, assessments like the VB-MAPP also highlight the stimuli that do not yet control desired speech-language responses; thus, interventions can be designed that incorporate stimulus control transfer procedures for more effective and efficient learning. Practitioners who have yet to access function-based speech-language assessments can nevertheless begin to analyze their existing evaluation tools (some of which may appear in the database) for the likely functions represented by these instruments. This first-step would be invaluable for informing treatments by assisting therapists in the selection and sequencing of appropriate targets for their interventions. Additional research is needed to further elucidate speaker-listener functions. For example, Poon and Butler (1972) suggest there may be developmental influences on intraverbal relations (e.g., different acquisition stages for how, when, where). As noted earlier, Baker et al. (2008) offer an initial functionbased taxonomy for evaluating speaker-listener repertoires following neurological impairment (i.e., aphasia). Lerman and colleagues (2005) discuss positive treatment implications by including existing responses in functional assessments of the verbal repertoire. Yes-no responding has been assessed and trained across the verbal functions (Shillingsburg, Kelley, Roane, Kisamore, & Brown; 2009) following demonstrations that these responses did not generalize from one operant (e.g., mand) to another (e.g., tact) without specific training. Finally, Carr and Firth (2005) call for researchers and practitioners alike to publish results of individual treatments based on Skinner’s (1957) analysis of verbal behavior. 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A comparison of verbal-behavior and linguistic-communication curricula for training developmentally delayed adolescents to acquire and maintain vocal speech. Behaviorology, 1, 31-46. *Williams, K. T. (1997). Expressive vocabulary test. Circle Pines, MN: American Guidance Service. *Zimmerman, I. L., Steiner, V. G., & Pond, R. E. (2002). Preschool language scale (4th ed.). San Antonio, TX: Pearson. Author Contact Information Correspondence concerning this article should be addressed to the first author. Barbara E. Esch Esch Behavior Consultants, Inc. P. O. Box 20002 190 SLP- ABA Volume 5, Issue No. 2 Kalamazoo, MI 49019 Phone: 561-676-7212 E-mail: [email protected] Kate B. LaLonde Esch Behavior Consultants, Inc. P.O.Box 20002 Kalamazoo, MI 49019 John W. Esch Esch Behavior Consultants, Inc. P. O. 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For more information, or place an ad, contact Halina Dziewolska by phone at (215) 462-6737 or e-mail at: [email protected] 191 SLP- ABA Volume 5, Issue No. 2 Effects of a Speaker Immersion Procedure on the Production of Verbal Operants Nirvana Pistoljevic, Claire Cahill, and Fabiola Casarini Abstract We studied the effects of a Speaker Immersion Procedure on the numbers of vocal verbal operants emitted in non-instructional settings (NIS) by two preschoolers with language delays. Prior to the intervention, the participants emitted low rates of vocal verbal behavior in NIS. The dependent variables were the numbers of vocal verbal operants emitted in three different NIS and the numbers of mands emitted in the presence of contrived establishing operations. The independent variable was the Speaker Immersion Procedure, an instructional tactic using contrived and naturally occurring establishing operations to increase opportunities to teach speaker behavior. Results showed an increase in numbers of vocal verbal operants emitted by participants following the implementation of the Speaker Immersion Procedure (SIP). Keywords: Speaker Immersion Procedure, Verbal Behavior, Establishing Operations, Motivating Operations, Vocal Verbal Operants, Mands, Tacts, Echoic, Spontaneous Speech, Language ______________________________________________________________________________ Introduction Children with native intellectual disabilities and children from impoverished backgrounds frequently lack or do not develop functional verbal repertoires naturally (Hart and Risley, 1995). Even when children with delays in language development receive behavioral language interventions, their prior lack of a history of reinforcement for vocal verbal communication calls for intensive language learning instruction (Greer, Chavez-Brown, Nirgudkar, Stolfi, & Rivera-Valdes, 2005; Greer & Keohane, 2005; Pistoljevic, 2008; Pistoljevic & Greer, 2006). These children need intensive language experiences to compensate for deficits in their learning history and to advance their verbal development. According to Woods (1984), when the verbal antecedents from the parents were absent, children with native disabilities were usually silent, lacking “spontaneous speech,” whereas typically developing children were more likely to initiate interactions without verbal antecedents from others. Many students with native or environmental disabilities acquire correct vocal verbal behavior during instruction but may not emit it spontaneously in non-instructional settings (NIS) (Greer, 2002; Nuzzolo-Gomez & Greer, 2004). What they lack is “independent” or “spontaneous” speaker behavior, including verbal operants emitted wit hout any verbal antecedent and used in ways that were not previously reinforced (Ross, Nuzzolo, Stolfi & Natarelli, 2006). This behavior is a major goal of language training programs. Williams and Greer (1993) compared the effects of linguistic and verbal behavior curricula on the acquisition of functional speech. For the linguistic curriculum, the students responded to the verbal behavior of the instructor (e.g., “What is that?”) by emitting intraverbal responses. In the verbal behavior curriculum, the student responses were under the control of non-verbal stimuli (i.e., the presence of the nonverbal stimuli served as an antecedent). Operant procedures were used for both methods and both produced the same number of correct responses. Overall, the verbal behavior curriculum resulted not only in the students’ learning more words but also in the maintenance and generalization of verbal operants. In other words, the two curricula produced two very different repertoires, and only the verbal behavior curriculum resulted in “spontaneous” speech under the control of non-verbal environmental stimuli. Typically developing children seem to learn to communicate in effortless ways. They are more likely to respond to nonverbal antecedents in order to initiate verbal interactions spontaneously, readily responding to the natural establishing operations (EOs) that control human communicative behavior (e.g., lack of social attention when attention is preferred for pure tacts; deprivation or aversive conditions for mands). Therefore, one possible reason why children with disabilities are often observed not emit pure 191 SLP- ABA Volume 5, Issue No. 2 tacts and mands in NIS is that they were taught to produce these verbal operants only under the partial antecedent verbal control of others. That is, tacts and mands were taught as intraverbals and the relevant direct control of nonverbal antecedents was never actually learned. In other words, these children learned to talk only when asked for a response (e.g., “What do you want?") and not in response to a natural EO (e.g., deprivation or aversive conditions). As an alternative, one could avoid verbal antecedents and arrange the environment to create EOs that would encourage the emission of pure mands (i.e., requests for desired items independent of verbal antecedents) (Pistoljevic, 2008). Within the verbal behavior model, speaker behavior is represented by six basic operants or functions, each defined by effects on the listener. Included are echoics, mands, tacts, intraverbals, textual responses and autoclitics (Skinner, 1957; Ross et al., 2006). Among these operants, tacts and mands are of particular interest for the current study. Tacts are controlled by the presence of stimuli and maintained by generalized reinforcement, while mands are controlled by specific motivational conditions (e.g., deprivation) and reinforced by what is specified in the mand itself. Skinner (1957) defined the mand as a verbal operant, which specifies its consequence, under the control of conditions of deprivation or aversive stimuli. When compared to other verbal operants, only the mand is controlled by motivational conditions, such as deprivation, satiation, and aversive stimulation. Additionally, the manipulation of these motivational variables can be used to evoke verbal behavior (Skinner, 1957). Incorporating previous work on motivation, Michael (1993) defined establishing operations (EOs) as "changes in the environment which alter the effectiveness of any object or event as reinforcement and simultaneously alter the frequency of the behavior followed by the reinforcement" (p. 191). Recently, the term motivating operation (MO) has been introduced as a replacement term for EO (Laraway, Snycerski, Michael, & Poling, 2001, 2003). The MO is comprised of the value altering effect, which either increases the reinforcing effectiveness of a stimulus, object, or event which is an EO or that decreases reinforcer effectiveness, which is an abolishing operation (AO). Differentiating among the types of EOs, Michael (1993) describes unconditioned establishing operations (UEO) as unlearned motivation such as deprivation of food, water, or sleep. The effect of the UEO is innate, but the behavioral response is learned. In contrast, conditioned establishing operations (CEO) are defined as learned motivation, for which social attention, toys, or money often function as reinforcers. Not only is the CEO learned, but the response is also learned. One category of CEO is called transitive CEOs, in which a stimulus condition “makes some other stimulus condition effective as a form of conditioned reinforcement, and evokes behavior that has obtained that item in the past” (Sundberg, 2004). Daily activities involve transitive CEOs as motivation, such as cooking, cleaning, or schoolwork. EOs are a component of language acquisition for typical children and are often incorporated as an independent variable into verbal behavior instruction for children with disabilities (Sundberg, 1993, 2004; Sundberg, Loeb, Hale, & Eigenheer, 2002; Sundberg & Michael, 2001; Sundberg & Partington, 1998). In fact, for mand training, if the EO is not in effect one cannot deliver mand instruction (Sundberg, 2004). But waiting for EOs to occur naturally in the environment limits the number of opportunities for mand instruction. For that reason, contrived EOs are often an essential component of mand instruction. For UEOs, the passage of time can increase the momentary value of the stimulus, as in the case of thirst or hunger. The UEOs can also be contrived, such as giving salty foods to increase the value of juice (Sund berg, 2004). For CEOs, the instructor can capture opportunities in which one stimulus increases the value of another stimulus. In the case of transitive CEOs, opportunities to conduct mand training can be contrived. Several experiments have identified EO tactics that have been effective in producing the motivational contexts necessary to teach speaker verbal capabilities (Hart & Risley, 1975; McGee, Krantz, Mason, & McClannahan, 1983; Ross, 1998; Ross & Greer, 2003; Ross et al., 2006; Schwartz, 1994; Tsiouri & Greer, 2003, Williams & Greer, 1993). Three common procedures that use EOs to increase speaker behavior are incidental teaching, behavior chain interruption strategy (BCIS), and brief motivational procedures with time delay (Ross et 192 SLP- ABA Volume 5, Issue No. 2 al., 2006; Schwartz, 1994). During incidental teaching, a speaker indicates, through gestures or comments, deprivation of an item or activity that he/she needs assistance to obtain. The listener (i.e. the experimenter) then provides verbal questions , modeling or expectant looks that function as prompts, inducing the speaker to emit a pre-determined response. When the speaker emits the target response, the desired item is contingently delivered. Experiments demonstrated that the incidental teaching procedure was effective in increasing the number of mands emitted after its implementation for preschool children diagnosed with autism (McGee, Morrier & Daly, 1999) and for young children with delays (Dunst, Bruder, Trivette, Raab, & McLean, 2001; Hart & Risley, 1975). The BCIS uses interruptions of routines or chained behaviors as an EO for both mands and tacts (Hall & Sundberg, 1987; Ross et al., 2006). The implementation of the BCIS tactic demonstrated to be successful in increasing mands for play by a child with autism (Sigafoos & Littlewood, 1999) and in increasing selection requests for elementary-school children with language delays (Grunsell & Carter, 2002). Hall and Sundberg (1987) presented instant coffee without hot water, increasing the value of the water and creating not only motivation, but also an opportunity for mand instruction. The brief motivational procedure incorporates time delay into the mand training and consists of the teacher presenting an item from which a student has been deprived, waiting a few seconds and delivering the requested item if the target response is emitted. This procedure was effective in increasing the rate of functional vocal speech for adolescents with developmental disabilities (Williams & Greer, 1993) and in improving the acquisition of vocal speech for young children with autism (Drash, High & Tudor, 1999). Overall, these procedures were found to be effective in increasing the occurrence of verbal behavior, but many studies suggested that they may not be the best tactic to facilitate or induce independent speaker behavior. In a comparison of the three types of EOs on the acquisition and maintenance of mands in preschoolers, all were found to be effective in acquisition, generalization, and maintenance of mands, although BCIS resulted in the slowest acquisition of mands (Schwartz, 1994). Carter and Grunsell (2001) found that BCIS has only been functional for creating EOs in the context of not naturally-occurring routines and Sundberg and Michael (2001) suggested that incidental teaching produces a too limited number and variety of EO to teach communication as it naturally occurs. Other studies on brief motivational procedures found that the mand function did not transfer to the tact function unless specific instruction was implemented (Nuzzolo-Gomez & Greer, 2004), suggesting that these motivational procedures may not be sufficient to establish speaker behavior across different functions, such as mand, tact and autoclitic. A strategy known as the Speaker Immersion Procedure (SIP) was developed through research to increase spontaneous speaker behavior (Greer & Ross, 2004; Ross, 1995, Ross et al. 2006; Williams & Greer, 1993). During SIP, the experimenter arranges environmental conditions to create increased opportunities for mands, requiring students to use different autoclitic frames to obtain items and activities or to make transitions in their environment (Reilly-Lawson & Greer, 2006; Ross et. al, 2006). SIP is particularly useful for students with limited mand and tact repertoires (Greer & Ross, 2008). The procedure is structured to make vocal communication behavior obtain maximum reinforcement with minimum effort. Vocal verbal manding is always easier and faster than crying, gesturing, or using other nonverbal topographies. During SIP, the student can obtain desired items or engage in preferred activities only if he or she emits the targeted vocal mand (e.g., “I want___ please”). Opportunities to mand items or routines are created and maintained until a physical response to an EO requires more effort than the emission of a vocal mand for the same item or routine (Greer & Ross, 2008). Students also learn from the correction procedure following the production of an incorrect mand. This procedure consists of echoics provided by the teacher. Ross, Nuzzolo, Stolfi, and Natarelli (2006) tested the effects of SIP when implemented for different amounts of time during the day on the independent language of four students with developmental 193 SLP- ABA Volume 5, Issue No. 2 disabilities. In the first experiment the participants were two students who emitted autoclitic mands only when prompted. In the second experiment, the participants were two students who could emit mands and tacts with autoclitics, but did not mand for desired stimuli or tact common items spontaneously. In the first experiment SIP was implemented during one 60-minute session daily, and in the second experiment it was implemented during one 10-minute session daily. During the SIP, students had to emit a verbal response to an EO for each movement, environmental change or activity change (i.e. to request a straw to drink from a juice box; to request a pencil to write their name). Instructional settings were rotated with NIS, and the participants were presented with a 10-second opportunity to mand while the experimenters withheld a targeted event or item. The item or event was delivered if the student emitted the mand. If the student did not emit the mand, an echoic model of the autoclitic mand was presented by the teacher, providing the student with another opportunity to respond. Results indicated significant increases in the numbers of independent mands emitted by all of the students, not only during the SIP but also during generalization probes. In this paper we report a systematic replication of Ross et al. (2006), in which EO probes and probes of vocal operants in the non-instructional setting were conducted prior to and following the SIP. For experimental control, the EO pre and post probes were matched such that the same opportunities were created. In addition, the specific EOs used for the probes were recorded to ensure that the mands taught during the SIP were different from those used in the probes. Another change from the original study was that the SIP sessions were continued until the participant emitted mands in the presence of EOs with 90% accuracy across two consecutive sessions. The students learned from the reinforcement and from the correction procedures provided through learn units (Albers & Greer, 1991; Greer 2002; Greer & Ross, 2008). Method Participants The participants were two male preschool students diagnosed with disabilities. The participants were selected because they emitted mands in the one-to-one instructional setting but emitted few appropriate vocal mands in the non-instructional setting (NIS). Participants were selected from a private publicly funded school for students with disabilities that used the Comprehensive Application of Behavior Analysis to Schooling (CABAS) model (Greer, 1994). The school was located in a suburb outside a large metropolitan area and the school day was five hours. Participants A and B were part of an inclusion classroom, with twelve students, one teacher, and three teaching assistants, with a teacher-student ratio of 1:3. The classroom included students with and without disabilities and consisted of 10 male students and two female students ranging from three to five years old. Participant A was a 3.11 year old male, functioning as a listener and emergent speaker (Greer & Ross, 2008). He emitted generalized mands using full sentences (i.e., “I want cookie please”) in the 1:1 instructional setting, but he emitted few appropriate mands and instead cried or gesturally indicated the preferred items or activities in the NIS. Participant B was a 3.7 year old male, functioning as an emergent listener-emergent speaker (Greer & Ross, 2008). He emitted 2-word mands (i.e. “Cookie please”) in the 1:1 instructional setting but he emitted low numbers of any vocal mands in the NIS, waiting passively after emitting gestural mands. The participants are described in Table 1, and examples of their independent verbal operants prior to and following the intervention are given in Table 2. 194 SLP- ABA Volume 5, Issue No. 2 Table 1. Description of Participants P1 Age 2 Level of Verbal Capability (based on Greer & Ross, 2008) A 3.11 • Listener • Emergent Speaker Standardized Test Scores Preschool Language Scale -4: • Expressive Communication: SS4 =78 • Auditory Comprehension: SS4 =66 • Total Language Score: SS4 =69 Repertoires (based on Greer & Ross, 2008) • Generalized Imitation • Following Directions • Tacts and Mands with Autoclitics During 1:1 Instruction • Listener Component of Naming WPPSI-R4 • Verbal IQ: SS3 =79 • Performance IQ: SS3 =76 • Full Scale IQ: SS3 =74 B 3.7 • Listener • Emergent Speaker Preschool Language Scale -4 • Expressive Communication: SS3 = 67 • Auditory Comprehension: SS3 = 61 • Total Language Score: SS3 = 60 • Generalized Imitation • Following Directions • Tacts and Mands with Autoclitics During 1:1 Instruction • Listener Component of Naming 1 P = participants Age = represented in years & months 3 SS = Standard Score 4 WPPSI-R = Wechsler Preschool & Primary Scale of Intelligence-Revised 2 Setting During the probe sessions and intervention, a classroom teacher and/or a teaching assistant collected data. The treatment sessions were conducted in the participants’ classroom and in the hallway during transitions from and to the bus. The probe sessions were all conducted in the classroom during regular activities. The EOs probes were conducted in the classroom’s bathroom, at the cubbies during morning and afternoon routines and at the lunch table, while the NIS probes were conducted in the classroom’s toy area, lunch table and activity tables, where at least one other student was always present. Definition of Behaviors Dependent variables. The dependent variables measured in this study were both the number of vocal verbal operants emitted during non-instructional time and mands emitted in the presence of EOs. The dependent variables were measured during probe sessions prior to and immediately following the SIP. Non-instructional setting (NIS) probes were conducted in the natural school setting, and the experimenters provided no EOs during probe session. NIS pre-probes were conducted for three consecutive days for both participants. Data were collected on the number of tacts and mands emitted by the students for 10-minute sessions in each setting, 195 SLP- ABA Volume 5, Issue No. 2 with a total of 30-minute daily pre-probes. Each setting included the presence of one or more students together with the target student. The NIS were the classroom’s tables during group activities (i.e. playing with blocks, play-dough or puzzles), the lunch table during lunch and the classroom’s toy area during free play. The procedure for the NIS probes, established by Pistoljevic and Greer (2006), consisted of 10minute observation sessions across three different settings. The experimenters collected the data for the numbers and functions of utterances students emitted spontaneously across the target settings (e.g. numbers of pure mands and tacts). Mands were defined as verbal operants that specify their reinforcers under relevant conditions (Skinner, 1957) and tacts as verbal operants that make contact with the environment or identify components of the environment resulting in the listener or reader providing a generalized reinforcer to the speaker or writer (Greer, in press). Autoclitics were defined as verbal behavior that functions to modify, quantify, and/or qualify the effect of other verbal operants such as mands or tacts (Greer, 2009; Skinner, 1957). Pure tacts and mands were defined as vocal verbal operants that are under the control of nonverbal antecedents. For example, as he found a missing piece of a puzzle, one of the participants emitted a pure tact “A train!” during the post-probe. An example of a pure mand with autoclitics emitted during the post-probe at the lunch table was the student saying, “I want my juice” when another student took the target student’s juice. An example of autoclitic tact was “An orange car!” The consequence for tact is generalized reinforcement (i.e. social praise or attention) emitted by the listener. The consequence for mand is the listener delivering to the student the item or activity specified in the mand. No intraverbal responses were recorded; the teacher did not interact with the student vocally. Tacts and mands are called impure when they are under the control of a vocal antecedent, for example “what is this?” for a tact and “do you want to go to the toy area?” for a mand. During the NIS probe sessions, Participants A and B received no vocal praise or correction from the teacher following the emission of verbal behavior. Peers present in the NIS functioned as the audience for the verbal operants emitted by these participants. Data on the exact word and sentences emitted by the students during the pre and post probes in the NIS were also collected (Table 2). For the second dependent variable, data were recorded on the number of mands emitted during establishing operation (EO) probes conducted before and after the SIP. For the pre-probe, 30 EOs were created or captured within a school day and the specific instances were recorded, so that the same 30 opportunities were created during the post-probes. To ensure that the opportunities were actually EOs, the experimenters contrived or waited for the occurrence of natural environment conditions that could induce the student to mand for a desired item or activity. Each EO (i.e., cubby blocked, book withheld, door closed) was presented by the experimenters, who waited 10 seconds for the response to be emitted by the students. If the target response (i.e., “I want book, please”, “Open door please”) was emitted, the item was delivered or the student was allowed to engage in the activity requested. If the target response was not emitted within 10 seconds, 10 more seconds were given and the EO was enhanced and exaggerated by looking expectantly at the student or by praising other students who were engaged in the activity desired by the target student. Data on the exact mands emitted by the participants before and after the SIP were also collected and summarized in Table 3. For the dependent variable, responses to EOs were recorded as non-vocal mands, non-target vocal mands, and target vocal mands. Non-vocal mands were defined as gestures, crying, or grabbing. Nontarget vocal mands were defined as single words or utterances with fewer words than the specified target forms. The target mand form was specified for each student based on previously acquired mand forms. Following the SIP, identical NIS and EO post probes were conducted. The EO post-probes used scripted EOs, in order to create the same mand opportunities as the ones created during the pre-probes. Immediately after the SIP, post-probes were conducted following procedures identical to those used during the pre-probes. One month after completion of the SIP, follow-up post probes were repeated to determine whether the effects were maintained. 196 SLP- ABA Volume 5, Issue No. 2 Table 2. Specific Verbal Operants Emitted by Participants During Three 30-Minute NIS Probes P1 A B Pre -Probes Post-Probes “I don’t want to eat my pizza” “Throw away” “Open please” “Blocks!” “Open please” “Computer!” “I want that one” “Open please” “Cake!” “I want to go to recess” “I want to clean up” “I don’t know” “Lie down” “A train!” “The end” “He flies!” “I don’t know” “I want my daddy” “I found money!” “A star!” “Stand here” “What are you doing?” “Now walk” “This is a man” “I want juice” “Where is my juice?” “I want my juice” “It’s Gordon!” “Good morning” “Thomas the train!” “I don’t want this” “Good night!” “Open please” “Give me that one, please” “I want another one” “Down!” “Where is the W?” “I made it” “Puzzle please” “Let’s do this” “An umbrella!” “orange car!” “All done!” “I want more” “I miss one” “I did this” “I found this” “This goes here” “Where is this” “I want this” “I can’t clean up!” “He falls down!” “Excuse me” “Here is your seat” “You have to sit down” “Come on!” “We need chair” “Have a seat!” “Follow me” “Ok” “away” “a book” “star!” “square!” “circle!” “An horse” “Help please” “Plate!” “This” “Thank you” “It’s purple” “Crayon” “circle” “Oh no!” “One, two, three, four, five” “Oh, thank you” “An heart” “Yellow” “I have a square” “Wow, circle” “Oh no” “Bye bye” “Help please” “Here you go!” “Help, please” “Thank you” “A sheep” “Oh oh, where did they go?” “Recess?” “thank you” “Puzzle” “N” “Look” “C” “Help, please” “It’s broken” “M” “N” “Ok” “It’s an helicopter” “I color” “All done” “It’s Vinny’s” “Blue!” “Oh Thomas” “Oh no!” “Here you go” “It’s broken” “The end” “Look here” “a book” “Ok, what happened?” “Brown” “Star” “Oh oh green” 1 P = Participant Independent variable. The independent variable in this study was the SIP in which the experimenter used learn units for mand instruction while increasing student opportunities by creating EOs. The experimenters created 30 EOs divided in two sessions of 15 minutes, with one during the morning, from the school bus arrival to the morning routine, and the other during lunch. EOs, defined as 197 SLP- ABA Volume 5, Issue No. 2 conditions which act to alter the momentary effectiveness of a reinforcer (Greer & Ross, 2008), were created using interrupted chain (i.e., withholding the straw after giving the juice box to the student; blocking access to a necessary or desired item or activity; withholding a necessary or desired item). After an EO occurred, the experimenter waited 10 seconds for the student to emit the correct vocal mand. To ensure that EOs were actually in place, the experimenter only counted instances in which participant manded either in target or non-target forms. In fact, only when the student manded was it considered as an opportunity and if, to the contrary, no mand was emitted, the student’s response was not recorded. For example, if the teacher had a cookie and the student manded by whining, grabbing, pointing, or vocally asking for it , only then was an EO considered to be in place. If the mand was emitted in the targeted form, the experimenter delivered the item or activity and recorded it as a correct response. If the mand was emitted in non-target form (e.g. crying, grabbing, reaching), the experimenter recorded it as an error and provided an echoic correction by modeling the correct response. The requested item or activity was not delivered unless the mand was emitted in target form, although in some cases, the item or activity could not be withheld. For example, if an EO was created for the student to mand to exit the school bus and he remained silent, the experimenter eventually had to allow the student off the bus. The target mand forms for Participant A were “I want ___ please,” “I need ___ please,” and “Give me ___ please.” The target mand form for Participant B was “___ please.” The SIP continued until the criterion of 90% correct responses for two consecutive sessions was met. Table 3. Examples of Vocal Mands Emitted by Participants in Response to Contrived EO Probes 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. EOs Withhold backpack Block door Block toy area Block bathroom door Withhold water Withhold soap Block flushing toilet Withhold book Withhold play-dough Utensils without food Straw without juice Block chair Pre -Probes “Door” “Flush” “Dora book” “Please” “Please” Post-Probes “I want my backpack, please” “Open please” “I want to go to toy area, please” “I want to go to the bathroom, please” “Give me water, please” “Give me soap, please” “I want to flush the water, please” “Give me Thomas, please” “Play-dough, please” “I want this, please” “I want juice, please” “I want to sit down please” For the SIP, mand instruction was delivered in "learn units". A learn unit is a measure of teaching defined by a 3 term contingency for the student and 2 or more three term contingencies for the teacher (Albers & Greer, 1991; Greer, 2002). Responses to the learn unit presentation from a teacher results in a response from the student and the student’s response occasions reinforcement or correction delivered by the teacher. Different teaching procedures in addition to learn units were used for each student, based on their instructional history (Greer & Keohane, 2005; Greer & Ross, 2008). For Participant A, the SIP was taught using the mand procedure (Greer & Ross, 2008), and for Participant B, a 1-second time delay procedure was used (Charlop & Trasowech, 1991; Ingenmey & Van Houten, 1991; Matson, Sevin, Fridley, & Love, 1990). For Participant A, the intervention was implemented with the mand procedure (Greer & Ross, 2008). During this procedure the experimenter showed a preferred item or activity to the student, waited three seconds and immediately delivered the item or activity if the student independently emitted the target response form, or provided an echoic correction if the student did not respond or emitted an incorrect response. For Participant B a 1-second time delay procedure (Charlop & Trasowech, 1991; Ingenmey & Van Houten, 1991; Matson, et al., 1990) was used. As an antecedent response prompt, 198 SLP- ABA Volume 5, Issue No. 2 time delay procedures use variations in the time intervals between presentation of the natural stimulus and the presentation of the response prompt. If the student did not independently respond one second after the presentation of the item or activity, the experimenter provided the student with an echoic prompt of the target response for the student to echo and receive the item or activity specified. During this errorless learning procedure, the students usually start to emit the correct response independently after a few sessions. Data Collection Data were collected by one or two experimenters during the NIS probe session using a pen, a clipboard, a timer, and a data collection sheet. The emission of tacts was recorded with a “T”, the emission of mands was recorded with an “M”, and the exact words said by the students were recorded (Tables 2 and 3). The data were then added across settings and graphed as the total number of tacts and mands emitted during the cumulative probe period. For the EOs probes data were collected using a pen, a clipboard, a timer, and a data sheet. After creating each EO, a plus (+) was collected for the student correctly emitting the target mand form, and a minus (-) was collected when a response was not emitted or it was emitted with a non-target form. The exact words emitted by the students were also recorded (See Table 3.) During the intervention a timer, a pen, and a data sheet were also used. A plus (+) was recorded for the emission of a target mand form and a minus (-) was recorded when the child did not emit the target form of a vocal mand. For Participant B, during the one-second time delay procedure, a “P” was recorded for correct responses emitted following a vocal prompt, and a plus (+) was recorded for the independent target form of responses while a minus (-) was collected for all non-target responses. The data were then graphed on a 30-learn unit graph as a closed circle for the correct independent responses and an open circle for prompted responses. Interobserver Agreement During the NIS probes, interobserver agreement (IOA) was conducted with two observers simultaneously collecting the data. For Participant A, during NIS pre-probes IOA was calculated for 44 % of the sessions, with 100% agreement. IOA was also calculated for 33% of NIS post probes, with 100% agreement. For Participant B, during NIS pre-probes, IOA was calcula ted for the 78% of the sessions, with 100% agreement. Design A delayed multiple probe design across participants (Horne & Baer, 1978; Pistoljevic & Greer, 2006) was used to compare the number of verbal operants emitted before and after the SIP in NIS and to compare the number of mands emitted during the EOs probes before and after the treatment. Results During the EOs pre-probes (Figure 1), Participant A emitted 0 target form mands, 6 vocal mands in a non-target form, and 24 non-vocal mands. Participant B emitted 0 target form mands, 5 non-target vocal mands, and 25 non-vocal mands. During the NIS pre-probes (Figure 2), Participant A emitted 1 tact and 3 mands during the first sessions, 1 tact and 1 mand during the second sessions, and 2 tacts and 1 mand during the third sessions. Participant B emitted 2 tacts and 1 mand during the first pre-probe session, 0 tacts and mands in the second sessions, and 3 tacts and 0 mands in the third session. During the SIP, the numbers of correct mands emitted by Participant A were 9, 19, 25, 27 and 28, and he met criterion after the fifth session. Participant B emitted 0, 1, 13, 18, 25, 21, 27, 28 correct mands 199 SLP- ABA Volume 5, Issue No. 2 during the SIP and met the criterion at the 8th session. For the EOs post-probes, Participant A emitted 26 target vocal mands, 4 non-target form mands, and 0 non-vocal mands. Participant B emitted 26 target vocal mands, 3 non-target form mands, and 1 nonvocal mand. 200 SLP- ABA Volume 5, Issue No. 2 Figure 1. The number of mands emitted during pre-, post-, and follow-up probes of 30 establishing operations for both participants Figure 2. The number of mands and tacts emitted during pre-, post-, and follow-up probes in 30-minutes across NIS for both participants During the NIS post-probes Participant A emitted 8 tacts and 6 mand in the first sessions, 5 tacts and 4 mands in the second sessions and 12 tact and 15 mands in the third sessions. During the post probes 201 SLP- ABA Volume 5, Issue No. 2 Participant B emitted 23 tacts and 2 mands in the first sessions, 10 tacts and 6 mands in the second sessions, and 14 tacts and 1 mand in the third sessions. The specific verbal operants emitted by participants in the NIS for the pre and post probes are listed in Table 2 and examples of mands emitted in response to EOs are given In Table 3. One month after the completion of SIP, follow-up post probes were repeated to measure the continued effects of the intervention. In the follow-up post-probes in the NIS setting, Participant A emitted 15 tacts and 12 mands and Participant B emitted 23 tacts and 5 mands. During the EO follow-up post- probes, Participant A emitted 29 target form mands, 1 non-target vocal mand, and 0 non-vocal mands. Participant B emitted 19 target form mands, 8 non-target vocal mand, and 3 non-vocal mands. Discussion This study was conducted to test the effects of the SIP on the number of independent vocal verbal operants emitted by students with low rates of spontaneous speaker behavior outside of instruction. During the SIP, participants were exposed to multiple EOs and mand instruction, where appropriate echoic models of mands were provided. These contrived motivating operations (Laraway, Snycerski, Michael, & Poling, 2001) had value-altering effects, increasing the reinforcing effectiveness of some object or event, and therefore creating an opportunity for a student to mand. In this experiment, following the SIP, the students’ rates of emission of spontaneous speech significantly increased in response to the EOs and during non-instructional time, One month after the intervention, the follow-up post-probes revealed that both participants maintained high levels of spontaneous speech compared to the baseline levels. In this experiment, the EOs and corresponding mands in the probes differed from those presented during the SIP. Controlling the EOs in this manner ensured that the mands taught were not identical to those in the probes. If the student emitted a mand in the probes following the SIP, he did not learn that particular mand during the intervention. Rather than simply acquiring the vocabulary to mand, the students may have learned a relationship between emitting appropriate vocal verbal behavior and delivery of reinforcement (e.g. their needs were meet more frequently). The effectiveness of the SIP may be due to the fact that during mand instruction, the necessary relationship between EOs and environmental circumstances in which the behavior is likely to be reinforced (such as the presence of an appropriate audience) was established. It is also possible that the procedure taught the students target responses that previously were not in their repertoire or that the outcomes were a result of the presentation of multiple EOs and corrections across many different settings, so that the instructional history necessary to acquire the target responses was produced. For both participants, not only did the numbers of pure mands increase in the NIS during the post-probes, but also the numbers of pure tacts significantly increased. The mean number of words emitted per utterance also increased, showing a wider use of autoclitics for Participant A. The student may have learned that vocal verbal behavior emitted increases the frequency of generalized reinforcement received from the environment (e.g. attention from adults). Interestingly, the experimenters also observed that the effects of SIP may have affected toilet training for Participant A. Prior to SIP, the student did not independently mand for the bathroom and had frequent accidents. After SIP was implemented, the student started to independently mand for the bathroom and no longer had accidents. Williams and Greer (1993) found that when EOs were incorporated and verbal antecedents were avoided, participants emitted more of what is typically characterized as spontaneous speech or the initiation of language interactions. Both Ross and Greer (2003) and Tsiouri and Greer (2003) replicated these findings as well. But, even when a child acquires a fluent speaker repertoire, learning new verbal 202 SLP- ABA Volume 5, Issue No. 2 operants in each class of responses (i.e. mands, tacts) may require separate direct instruction for each (Greer & Ross, 2008; Pistoljevic & Greer, 2006; Ross & Greer, 2003). Therefore, it is safe to say that this procedure and the results it yielded is only the first step in a long path of instruction for these students. A speaker needs to become a speaker-as-own listener, a Namer, Observational Learner, Reader, Writer, Self-Editor, and a Problem Solver as defined by Greer and Keohane, 2005, Greer and Ross, 2008. References Albers, A., & Greer, R.D. (1991). Is the three term contingency trial a predictor of effective instruction? Journal of Behavioral Education, 1, 337-354 Carter, M., & Grunsell, J. (2001). The behavior chain interruption strategy: A review of research and discussion of future directions. 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(2005). The evolution of verbal behavior in young children. Behavioral Development Bulletin, 1, 31-48. Greer, R.D., Keohane, D.D., & Healy, O. (2002). Quality and comprehensive applications of behavior analysis to schooling. The Behavior Analyst Today, 3, 120-132. Greer, R. D., & Ross, D.E. (2004). Research in the induction and expansion of complex verbal behavior. Journal of Early Intensive Behavioral Intervention, 1, 141-165 Greer, R. D., & Ross, D.E. (2008). Verbal behavior analysis: Inducing and expanding new verbal capabilities in children with language delays. New York, NY: Allyn and Bacon. Greer, R. D., Stolfi, L., Chavez-Brown, M., & Rivera-Valdes, C. (2005).The emergence of the listener to speaker component of naming in children as a function of multiple exemplar instruction. The Analysis of Verbal Behavior, 21, 123-134. Grunsell, J., & Carter, M. (2002). The behavior chain interruption strategy: Generalization to out-ofroutine contexts. 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Changes in student and teacher responses in observed and generalized settings as a function of supervisor observations. Journal of Applied Behavior Analysis, 25, 153164. Laraway, S., Snycerski, S., Michael, J., & Poling, A. (2001).The abative effect: A new term to describe the action of antecedents that reduce operant responding. The Analysis of Verbal Behavior, 18, 101–104. Laraway, S., Snycerski, S., Michael, J., & Poling, A. (2003). Motivating operations and terms to describe them: Some further refinements. Journal of Applied Behavior Analysis, 36(3), 407-414. Lamm, N., & Greer, R. D. (1991). A systematic replication and a comparative analysis of CABAS. Journal of Behavioral Education, 1, 427-444. Matson, J. L., Sevin, J. A., Fridley, D., & Love, S. R. (1990). Increasing spontaneous language in three autistic children. Journal of Applied Behavior Analysis, 23, 227-233. McGee, G. G., Krantz, P.J., Mason, D., & McClannahan, L. E. (1983). 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Pistoljevic, N., & Greer, R. D. (2006). The effects of daily intensive tact instruction on preschool students’ emission of pure tacts and mands in non-instructional setting. Journal of Early and Intense Behavior Intervention, 3(1), 103-120. Reilly-Lawson, T., & Greer, R. D. (2006). Teaching the function of writing to middle school students with academic delays. Journal of Early and Intensive Behavior Intervention, 3(1), 151-170. Ross, D. E. (1995). Verbal immersion to increase speaker behavior. Poster presentation at the annual international conference for the Association for Behavior Analysis, Washington, DC. Ross, D. E. (1998). Generalized imitation and the mand: Inducing the first instances of vocal verbal behavior in young children with autism. (Doctoral dissertation, Columbia University, 2008). Abstract from: UMI Proquest Digital Dissertations [on-line]. Dissertations Abstract Item: AAT 9 834364. 204 SLP- ABA Volume 5, Issue No. 2 Ross, D. E., & Greer, R. D. (2003). Generalized imitation and the mand: Inducing first instances of speech in young children with autism. Research in Developmental Disabilities, 24, 58-74. Ross, D. E., Nuzzolo, R., Stolfi, L., & Natarelli, S. (2006). Effects of speaker immersion on independent speaker behavior of preschool children with verbal delays. Journal of Early and Intense Behavior Intervention, 3, 135-149 Ross, D. E., Singer-Dudek, J., & Greer, R. D. (2005). The Teacher Performance Rate Accuracy scale (TPRA): Training as evaluation. Education and Training in Developmental Disabilities, 40(4), 411-423. Schwartz, B. S. (1994). A comparison of establishing operations for teaching mands to child ren with language delays. Doctoral dissertation, Columbia University, 1994. Abstract from UMI Proquest Digital Dissertations [on-line]. Dissertations Abstracts Item: AAT9424540. Selinske, J. E., Greer, R. D., & Lodhi, S. (1991). A functional analysis of the comprehensive application of behavior analysis to schooling. Journal of Applied Behavior Analysis, 24, 107-117. Sigafoos, J., & Littlewood, R. (1999). Communication intervention on the playground: A case study on teaching requesting to a young child with autism. International Journal of Disability, Development and Education, 46(3), 421-429. Skinner, B. F. (1957). Verbal behavior. Acton, MA: Copley Publishing Group and the B. F. Skinner Foundation. Sundberg, M. L. (1993). The applications of establishin g operations. The Behavior Analyst, 16, 211-214 Sundberg, M. L., Loeb, M., Hale, L., & Eigenheer, P. (2002). Contriving establishing operations to teach mands for information. The Analysis of Verbal Behavior, 18, 15-29. Sundberg, M., & Michael, J. (2001).The benefits of Skinner's analysis of verbal behavior for children with autism. Behavior Modification, 25(5), 698-724. Sundberg, M.L., & Partington, J. W. (1998). Teaching language to children with autism or other developmental disabilities. Danville, CA: Behavior Analysts, Inc. Sundberg, M. L. (2004). A behavioral analysis of motivation and its relation to mand training. In L. W. Williams (Ed.), Developmental disabilities: Etiology, assessment, intervention, and integration. Reno NV: Context Press. Tsiouri, I., & Greer, R. D. (2003). Inducing vocal verbal behavior through rapid motor imitation training in young children with language delays. Journal of Behavioral Education, 12, 185-206. Williams, G., & Greer, R. D. (1993). A comparison of verbal-behavior and linguistic -communication curricula for training developmentally delayed adolescents to acquire and maintain vocal speech. Behaviorology, 1, 31-46. Acknowledgements The authors would like to thank Dr. R. D. Greer, professor of Education and Psychology at Teachers College and The Graduate School of Arts and Sciences at Columbia University for his endless guidance and support. Also, we thank the staff, students, and families of The Fred S. Keller School for their participation and continued support. 205 SLP- ABA Volume 5, Issue No. 2 Author Contact Information Nirvana Pistoljevic, PhD Teachers College, Columbia Univ. 525 125th Street, PO Box 223 New York, NY 10027 Phone: 212-678-8328 [email protected] Claire Cahill, MA Fred S. Keller School PO Box 716 680 Oak Tree Road Palisades, NY 10964 Phone: 845-359-8846 [email protected] Fabiola Casarini, MA Fred S. Keller School PO Box 716 680 Oak Tree Road Palisades, NY 10964 Phone: 845-359-8846 [email protected] ADVERTISEMENT ADVERTISING IN BAO JOURNALS If you wish to pla ce an advertisement in any of our journals, you can do it by contacting us. 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