Revisiting Topography-Based and Selection-Based Verbal Behavior.

In topography-based verbal behavior, different antecedent stimuli control different topographies of responding, whereas in selection-based verbal behavior, different antecedent stimuli control the selection of visually distinct stimuli from an array of options. In this article, we point out three variable characteristics of selection-based behavior, highlighted by recent technological developments, that affect its similarity to topography-based behavior: The extent to which stimuli can be constructed from minimal units, the size and composition of the selection array, and the similarity of response-produced stimuli to verbal stimuli that are prevalent in the speaker's verbal community. Although a distinction between topography-based and selection-based behavior has merit, particular characteristics of a selection-based verbal behavior modality may often be more relevant for researchers and clinicians to consider than its status as selection-based.

Explaining First Language Acquisition in Terms of Basic Behavioral Processes: Introduction to the Special Section.

This special section of Perspectives on Behavior Science follows up on a virtual panel discussion on the role of operant and Pavlovian processes in children's language learning. We present four articles, including two contributed by panelists, that illustrate the explanatory power of operant conditioning processes in the study of language.

Training sequence effects on emergent conditional discriminations: Replication and extension to selection-based training.

We examined the replicability and generality of a previously reported training sequence effect on emergent conditional discriminations in the intraverbal naming task. In Experiment 1, a tact-intraverbal (TI) group learned first to vocally label 6 visual patterns and then to intraverbally relate pairs of verbal labels, whereas an intraverbal-tact (IT) group received the same training in the opposite sequence. Emergent conditional discriminations among pattern stimuli were assessed in match-to-sample (MTS) format. Experiment 2 was identical, except vocal tact and intraverbal training were replaced with selection-based training in which the verbal labels were text stimuli. Compared to the IT sequence, the TI sequence resulted in greater mean accuracy at test (Experiment 1), higher yields (Experiment 2), and shorter reaction times (Experiment 2). Experiment 2 data suggested the TI group's performance might be less dependent on intact intraverbal relations relative to the IT group, but related to participants' reports of visualization during intraverbal training. The results suggest the sequence effect is replicable and occurs in experimental preparations commonly used to study derived stimulus relations. They also provide novel support for the hypothesis that participant behavior during training alters sources of stimulus control available at test.

Translational evaluation of training structures in equivalence-based instruction.

We used a laboratory preparation to evaluate the claim that equivalence-based instruction (EBI) is an efficient form of instruction due to eliminating the need for emergent relations to be taught. Three groups of college students received training to establish 3 stimulus classes with 4 members in each class. Two groups received either a linear series (EBI-LS) or a 1-to-many training structure (EBI-OTM group). A control group received complete instruction (CI) that targeted all possible relations between the members of each class. The EBI-OTM group required fewer trials to complete instruction compared to CI, whereas EBI-LS did not. The EBI-OTM and the CI groups performed equally well on a posttest that followed initial attainment of the mastery criterion, whereas the EBI-LS group performed more poorly than the other 2. The groups' performance on a function transfer test did not differ. The results support the claim that compared to CI, EBI is an efficient form of instruction when it follows an OTM structure. However, they also suggest this efficiency advantage cannot be attributed to the fewer relations that need to be taught in EBI, as the EBI-OTM and the EBI-LS groups were trained on the same number of relations.

Emergent Tact Control Following Stimulus Pairing: Comparison of Procedural Variations.

We examined emergent tact control following stimulus pairing, using 2 different stimulus presentation arrangements. In the word-first condition, presentation of the auditory stimulus preceded the visual stimulus, and in the image-first condition, the visual stimulus preceded the auditory stimulus. Eight children (2-5 years old) participated. In Experiment 1, 4 children were exposed to 3 sessions in each condition with a new set of stimuli in each session. In Experiment 2, 2 of the same children received repeated exposure to the same stimulus sets. Experiment 3, with new participants, was identical to Experiment 1, except visual and auditory stimuli overlapped during the presentation. Postsession probes documented emergent stimulus control over 1 or more vocal responses for 7 of the 8 participants. Participants were more likely to make echoic responses with the visual stimulus present in the word-first condition; however, emergent tact control was unaffected by the order of the stimulus presentation. Additional research is needed on stimulus-pairing procedures and on the role of echoic responding in emergent tact control.

Efficiency of equivalence-based instruction: A laboratory evaluation.

In equivalence-based instruction (EBI), a large number of stimulus relations can be established through direct instruction of a smaller number of strategically selected relations. We evaluated the efficiency and other potential benefits of EBI in 2 between-subjects experiments with college students that compared EBI with complete instruction (CI). In Experiment 1 (n = 50), mastery criteria in both conditions required an equal number of equally sized trial blocks at equal accuracy. Under those conditions, trials to passing posttests did not differ significantly between groups during the establishment of 3-member classes or during expansion to 4- and 5-member classes. In Experiment 2 (n = 48), mastery criteria were equated across conditions in terms of the number of consecutive correct trials required for each trial type. Under those conditions, EBI required fewer trials to complete than did CI. Neither experiment found an advantage of EBI over CI in terms of facilitating future learning or maintenance of class-consistent responding. Overall, the results suggest that greater efficiency of EBI compared to CI may largely be attributed to learning assessment practices, but additional research is warranted with additional EBI training structures and trial arrangements.

Baseline training sequence affects speed of emergent conditional discriminations.

We examined the effects of baseline training sequence on the emergence of conditional discriminations in an intraverbal naming task. Thirty-two college students were randomly assigned to two groups. The tact-intraverbal (TI) group first learned to vocally tact eight visual stimuli using a unique verbal label for each stimulus, and then to intraverbally relate four pairs of verbal labels. The intraverbal-tact (IT) group received the same training but in the opposite sequence. Both groups then received a match-to-sample test involving the visual stimuli alone. On average, the TI group had significantly shorter reaction times than the IT group throughout all four test blocks, even when controlling for intraverbal retention, which was lower in the IT group. Accuracy on the MTS test did not differ significantly between groups when controlling for intraverbal retention. However, MTS accuracy and intraverbal retention were strongly correlated in the IT group but uncorrelated in the TI group. We suggest the effect of training sequence reflects different sources of stimulus control available to subjects in different groups when confronted with the novel MTS trials.

Applying the Taxonomy of Validity Threats from Mainstream Research Design to Single-Case Experiments in Applied Behavior Analysis.

Mainstream research design in the social and behavioral sciences has often been conceptualized using a taxonomy of threats to experimental validity first articulated by Campbell and his colleagues (Campbell & Stanley, 1966; Cook & Campbell, 1979). The most recent update of this framework was published by Shadish, Cook, and Campbell (2002), in which the authors describe different types of validity and numerous threats to each primarily in terms of group-design experiments. In the present article, we apply Shadish et al.'s analysis of threats to internal, external, statistical conclusion, and construct validity to single-case experimental research as it is typically conducted in applied behavior analysis. In doing so, we hope to provide researchers and educators in the field with a translation of the validity-threats taxonomy into terms and considerations relevant to the design and interpretation of applied behavior-analytic research for the purposes of more careful research design and the ability to communicate our designs to individuals outside of behavior analysis, using their own vocabulary.

Stimulus presentation order in receptive identification tasks: A systematic replication.

Conflicting recommendations exist in the literature regarding the optimal order of stimulus presentation when teaching auditory-visual conditional discriminations. The present study examined the generality of a previously demonstrated advantage of presenting the auditory sample before visual comparisons (sample-first condition) over the reverse sequence (comparison-first condition). Participants were four typically developing 5- and 6-year-old boys. The procedures of Petursdottir and Aguilar (2016) were systematically replicated with the addition of a prompted error correction trial following each incorrect response. Overall, there were more instances of quicker mastery in the sample-first condition (four of seven evaluations) than in the comparison-first condition (two of seven evaluations). A comparison-first advantage was associated with slower acquisition in both conditions than in the remaining evaluations, and an analysis of stimulus and position bias yielded tentative evidence for unwanted sources of stimulus control.

Effects of response-contingent stimulus pairing on vocalizations of nonverbal children with autism.

Research on stimulus-stimulus pairing to induce novel vocalizations in nonverbal children has typically employed response-independent pairing (RIP) procedures to condition speech sounds as reinforcers. The purpose of the present study was to evaluate the effects of a response-contingent pairing (RCP) procedure on the vocalizations of three nonverbal boys diagnosed with autism spectrum disorder. During RCP, adult-delivered sounds that were either paired with a preferred item (target sounds) or not (nontarget sounds) were presented contingent on a button-press response. In Experiment 1, RCP was compared with an RIP procedure, in which the timing of sound presentations was yoked to the preceding RCP session. RCP produced a greater effect on all participants' target vocalizations than RIP. Experiment 2 demonstrated the effects of differential reinforcement of the vocalizations induced in Experiment 1. The results suggest that RCP may develop vocalizations more reliably than RIP procedures.

Application of a lag contingency to reduce perseveration on circumscribed interests.

OBJECTIVE: To evaluate the effects of a lag reinforcement contingency on the conversation topics of children diagnosed with autism who perseverated on circumscribed interests (CIs). METHOD: Single-case design study with two participants, age 11 and 12 years. A functional analysis employed an alternating-treatments design to assess effects of contingent attention on conversational behavior. A multiple-baseline with an embedded reversal design was employed in a subsequent lag contingency analysis, in which the conversation partner provided attention at the end of each 10 s interval if the content of the participant's conversation met the requirement of a Lag 0, Lag 1, or Lag 2 contingency. RESULTS: The participants' conversational behavior was sensitive to a conversation-partner's attention as a consequence. Lag contingencies successfully altered the prevalence of CI-related and-unrelated talk. CONCLUSION: Lag contingencies can shift conversation content away from CIs, but further research is needed to identify appropriate treatment goals with respect to variability and content.

The impact of Verbal Behavior on the scholarly literature from 2005 to 2016.

B. F. Skinner's (1957) Verbal Behavior had a limited influence on empirical research in the first few decades following its publication, but an increase in empirical activity has been evident in recent years. The purpose of this article is to update previous analyses that have quantified the influence of Verbal Behavior on the scholarly literature, with an emphasis on its impact on empirical research. Study 1 was a citation analysis that showed an increase in citations to Verbal Behavior from 2005 to 2016 relative to earlier time periods. In particular, there was a large increase in citations from empirical articles. Study 2 identified empirical studies in which a verbal operant was manipulated or measured, regardless of whether or not Verbal Behavior was cited, and demonstrated a large increase in publication rate, with an increasing trend in the publication of both basic and applied experimental analyses throughout the review period. A majority of the studies were concerned with teaching verbal behavior to children with autism spectrum disorder and other developmental disabilities, but a variety of other basic and applied research topics were also represented. The results suggest a clearly increasing impact of Verbal Behavior on the experimental analysis of behavior on the 60th anniversary of the book's publication.

Order of stimulus presentation influences children's acquisition in receptive identification tasks.

Receptive identification is usually taught in matching-to-sample format, which entails the presentation of an auditory sample stimulus and several visual comparison stimuli in each trial. Conflicting recommendations exist regarding the order of stimulus presentation in matching-to-sample trials. The purpose of this study was to compare acquisition in receptive identification tasks under 2 conditions: when the sample was presented before the comparisons (sample first) and when the comparisons were presented before the sample (comparison first). Participants included 4 typically developing kindergarten-age boys. Stimuli, which included birds and flags, were presented on a computer screen. Acquisition in the 2 conditions was compared in an adapted alternating-treatments design combined with a multiple baseline design across stimulus sets. All participants took fewer trials to meet the mastery criterion in the sample-first condition than in the comparison-first condition.

Emergence of Intraverbal Responding Following Tact Instruction with Compound Stimuli.

Effective intraverbal responding often requires control by multiple elements of a verbal stimulus. The purpose of this study was to examine the emergence of such intraverbal relations following tact instruction with compound stimuli and to analyze any resulting error patterns. Participants were seven typically developing children between 3 and 5 years of age. After being taught to tact four overlapping compound stimuli that differed along color and shape dimensions, participants were tested for emergent intraverbal responding. Three participants performed with high accuracy and four with intermediate accuracy when correct intraverbal responding required control by multiple elements (i.e., color names and shape names) of the verbal stimulus. Five participants performed with high accuracy when intraverbal responding required control by only a single stimulus element, and all participants showed emergence of reverse intraverbal relations when the response required naming only a single stimulus element (i.e., color or shape). There was an insufficient number of errors to perform detailed error analyses at the individual level, but overall, the first element of a verbal stimulus was more likely to exert control over the response than the second element, and color words were more likely to exert control than shape words. Results suggest that individual stimulus elements acquired independent control over the responses that had been established as tacts.

Intraverbal naming and equivalence class formation in children.

Six typically developing children between 5 and 7 years of age underwent match-to-sample training to establish three-member equivalence classes after first acquiring a unique name for each stimulus. Horne and Lowe's (1996) naming hypothesis predicts that under those circumstances, match-to-sample training contingencies may establish intraverbal relations between the unique names, which in turn guide correct responses on a subsequent test for stimulus equivalence. Following training of baseline relations (AB and AC), participants received an equivalence test followed by an intraverbal test. Performance on the two tests co-varied, such that three participants passed both tests, and three participants failed repeated administrations of both tests, including a modified version of the equivalence test designed to promote intraverbal responding. The participants who failed the equivalence test, however, did so primarily due to poor performance in transitivity trials, but performed accurately in symmetry trials. After training of a third relation (BC), all three participants performed accurately in a symmetry test for the remaining untrained relations (BA, CA, and CB); two of them in the absence of relevant intraverbal repertoires.

Emergence of visual-visual conditional discriminations.

We assessed the emergence of visual-visual conditional discriminations following training of vocal tact and intraverbal relations. Ten preschool-age children learned to vocally tact six visual stimuli, A1 through B3. Next, they learned to respond intraverbally to the dictated names of A1, A2, and A3 by vocalizing the names of B1, B2, and B3, respectively. Emergent A-B and B-A relations were tested in a visual-visual match-to-sample (MTS) task. Five of ten participants passed the test, with or without a prompt to tact the sample stimulus. Four of the five failed a reverse intraverbal test that involved responding to dictated names of B stimuli by vocalizing names of A stimuli. The remaining participants failed the MTS test, apparently due to failures to maintain the trained vocal responses throughout testing. Accurate MTS performance in the absence of bidirectional intraverbal relations appears to contradict Horne and Lowe's (1996) analysis of the possible role of intraverbal naming in emergent stimulus control.

The Functional Independence of Mands and Tacts: Has It Been Demonstrated Empirically?

Recently, there has been a proliferation of research on the functional independence of two of Skinner's (1957) verbal operants, the mand, and the tact. This research has produced highly variable results. In this article, we provide a critical review of the literature on mand-tact independence, a literature that has implications for both theory and practice. Included in the review are 17 studies with a total of 66 participants who were tested for mand emergence following tact training, tact emergence following mand training, or both, and 11 additional studies that systematically manipulated variables expected to affect the outcomes of such tests. A primary finding is that most studies to date suffer from problems with construct validity. However, it may be justifiable to conclude that the literature provides at least weak support for the functional independence of mands and tacts. Future investigators should avoid the major construct validity pitfalls described in this article, describe participant characteristics more thoroughly, and consider alternative approaches to studying mand-tact independence.