Stimulus Control Topographies Research Articles

Relating in the Wild: Toward an Analysis of Equivalence Relations Under More Naturalistic Conditions.

Since the first proposal 50years ago, numerous experiments have documented how arbitrarily related stimuli can become functionally interchangeable. These studies have sought to understand how different variables can moderate the probability of equivalence class formation. However, the well-established evidence regarding this phenomenon in experimental settings does not necessarily guarantee an understanding about how equivalence relations are produced in natural settings. In typical experiments, experimenters control critical variables to produce equivalence relations, such as, the requirement of proficiency with baseline relations, the number of opportunities to relate two or more stimuli, the efforts to promote stimulus control topography coherent with the experimenter-defined relations, etc. All these variables, however, are not controlled in our daily lives. The present article elucidates how some differences between experimental and natural settings can likely affect how the phenomenon of equivalence relations can occur in noncontrolled, naturalistic environments. Furthermore, we suggest new areas of research to promote the generalization of basic experimental data to contingencies in our daily lives.

Merging meaningful classes and abstract equivalence classes by exclusion.

The current experiment assessed whether relating abstract stimuli with familiar pictures by exclusion would produce the formation of a meaningful equivalence class. Ten participants learned conditional discrimination relations with abstract stimuli and established equivalence classes (ABC classes). They then learned DA (D1A1, D2A2, and D3A3) conditional discriminations with written words as D stimuli; two words (D1 and D2) were meaningful stimuli in the participants verbal community ("Dentist" and "Baker"), whereas the third (D3) was a pseudoword ("Tabilu"). In testing trials, participants evidenced derived relations between pictures related preexperimentally to D1 and D2 with the experimental equivalence classes related to D1 and D2. For some participants, the decontextualized stimuli were a set of boat pictures (Condition 1), whereas for others they were a set of miscellaneous pictures (Condition 2). Participants in both conditions successfully matched decontextualized pictures (unrelated to dentist and baker contexts) to all abstract stimuli in the class related to D3 (exclusion responding). In Condition 1 the meaning reported to the word Tabilu was similar across participants, but in Condition 2 participants showed more variations to answer to the meaning of Tabilu. These results suggest that exclusion learning can occur under different stimulus control topographies.

Training Modality and Equivalence Class Formation under the Simultaneous Protocol: A Test of Stimulus Control Topography Coherence Theory

This experiment explored how training modality influenced the formation of three-node, five-member equivalence classes during the simultaneous protocol by 23 college students. The baseline relations were established in one of three ways: concurrently (CONC; i.e., all together), serially (SER; i.e., one after another)—both on a trial and error basis—or serially and “errorlessly” by use of a constructed response matching to sample procedure (CRMTS). After training, class formation was assessed with test blocks that contained all baseline relations trials and probe trials for symmetry, transitivity, and equivalence. Error percentages during the acquisition of the baseline relations was highest during concurrent training, lower during serial training, and lowest during constructed response training. Yet, a similar percentage of participants formed classes in each training condition. Thus, the likelihood of equivalence class formation under these variants of the simultaneous protocol was not influenced by training modality or prevalence of errors during acquisition. In addition, only some of the transient nonclass-indicative stimulus control topographies that emerged during training resurged during testing. These results challenge predictions regarding class formation posited by stimulus control topography coherence theory.

Effects of stimulus presentation order during auditory-visual conditional discrimination training for children with autism spectrum disorder.

Children with autism spectrum disorder are typically taught conditional discriminations using a match-to-sample arrangement. Consideration should be given to the temporal order in which antecedent stimuli (the sample and comparison stimuli) are presented during match-to-sample trials, as various arrangements have been used in the extant literature. The purpose of the current study was to compare the effects of four stimulus presentation orders on the acquisition of auditory-visual conditional discriminations. The study included participants from a clinically relevant population (three children with autism spectrum disorder), employed clinically relevant teaching procedures, and included two presentation formats not included in previous comparison evaluations (simultaneous and sample-first with re-presentation conditions). Results were found to be learner-specific; that is, a different stimulus presentation format was most efficient for each participant. We provide suggestions to evaluate stimulus control topographies and enhance experimental control in match-to-sample arrangements.

Understanding behavior under nonverbal transitive-inference procedures: Stimulus-control-topography analyses

Following training with verbal stimulus relations involving A is greater than B and B is greater than C, verbally-competent individuals reliably select A>C when asked “which is greater, A or C?” (i.e., verbal transitive inference). This result is easy to interpret. Nonhuman animals and humans with and without intellectual disabilities have been exposed to nonverbal transitive-inference procedures involving trained arbitrary stimulus relations. Following the training of A+B-, B+C-, C+D-, and D+E-, B reliably is selected over D (i.e., nonverbal transitive inference). Such findings are more challenging to interpret. The present research explored accounts of nonverbal transitive inference based in transitive inference per se, reinforcement, such as value-transfer theory, and operant stimulus control. In Experiment 1, college students selected B>G following the training of A+B-, B+C-, C+D-///E+F-, F+G-, and G+H- (where///signifies the omission of D+E-). In Experiment 2, college students selected B>G following the training of A+B-, B+C-, C+D-///E+F-, F+G-, and G+X- (where X refers to 10 stimuli that alternated across trials). In Experiment 3, college students selected G>B following the training of Y+B-, B+C-, C+D-///E+F-, F+G-, and G+X- (where Y and X refer to 10 stimuli, respectively, that alternated across trials). These findings are discussed in the context of operant stimulus control by offering an approach based in stimulus B typically acquiring only a select stimulus control topography.

Analyzing the Stimulus Control Acquisition in Simple Discrimination Tasks through Eye Movement

In order to investigate whether simultaneous or successive presentation of stimuli is related to the duration of eye fixation (i.e., the time spent gazing a specific stimulus), this study described the eye movements of young adults in simultaneous and successive simple discrimination tasks. Using 12 landscape scenes as visual stimuli, three participants were exposed to a simple discrimination training with simultaneously presented stimuli (Si Procedure) and then to a second simple discrimination training with successively presented stimuli (Su Procedure). Another three participants were exposed to the Procedure in the opposite order. In both cases, the learning criterion was that at least 90% of the responses should be correct in one block. Eye movements were recorded during the whole experiment. Participants achieved the learning criteria in both procedures. Beyond that, eye fixation time in the Su Procedure was higher than in the Si Procedure, regardless of the training sequence. Taken together with previous results in different experiments, our findings suggest that the duration of eye fixation plays a central role in the establishment of different stimulus control topographies.

Emergent identity but not symmetry following successive olfactory discrimination training in rats.

The search for symmetry in nonhuman subjects has been successful in recent studies in pigeons (e.g., Urcuioli, 2008). The key to these successes has been the use of successive discrimination procedures and combined training on identity, as well as arbitrary, baseline relations. The present study was an effort to extend the findings and theoretical analysis developed by Urcuioli and his colleagues to rats using olfactory rather than visual stimuli. Experiment 1 was a systematic replication of Urcuioli's (2008) demonstration of symmetry in pigeons. Rats were exposed to unreinforced symmetry probes following training with two arbitrary and four identity conditional discriminations. Response rates on symmetry probe trials were low and provided little evidence for emergent symmetry in any of the seven rats tested. In Experiment 2, a separate group of six rats was trained on four identity relations and was then exposed to probe trials with four novel odor stimuli. Response rates were high on identity probe trials, and low on nonmatching probe trials. The similar patterns of responding on baseline and probe trials that were shown by most rats provided a demonstration of generalized identity matching. These findings suggest that the development of stimulus control topographies in rats with olfactory stimuli may differ from those that emerge in pigeons with visual stimuli. Urcuioli's (2008) theory has been highly successful in predicting conditions necessary for stimulus class formation in pigeons, but may not be sufficient to fully understand determinants of emergent behaviors in other nonhuman species.

O uso do Procedimento Blocado no Ensino de Discriminações Condicionais de Identidade para em Pessoas com Autismo: Efeitos do emprego de Três Estímulos Modelo

O procedimento blocado é um dos procedimentos eficazes para o ensino de escolha de acordo com o modelo. O procedimento tipicamente emprega dois estímulos de comparação e alterna dois estímulos modelo em blocos com um determinado número de tentativas consecutivas, que é reduzido até que os modelos são apresentados aleatoriamente. Entretanto, o procedimento é considerado ineficiente por requerer um número grande de tentativas e ensinar apenas duas relações. O presente estudo investigou os efeitos do aumento de dois para três estímulos modelo na aprendizagem de relações de identidade em pessoas com autismo. Participaram do estudo cinco indivíduos com autismo. Cada sessão tinha 24 tentativas; os passos iniciais apresentavam um mesmo estímulo modelo em uma sessão. À medida que o participante respondia com precisão, os três estímulos modelo eram apresentados em números de tentativas consecutivas cada vez menores na sessão: de 24 para 8, de 8 para 4, de 4 para 2; e em sequência aleatória. Depois de aprendidas novas relações de identidade, os participantes eram submetidos a um teste de generalização. Todos os participantes aprenderam relações de identidade com pelo menos dois conjuntos de estímulos, embora procedimentos remediativos tenham sido necessários para alguns participantes. Quatro de cinco participantes demonstraram generalização do responder. O procedimento blocado funcionou para o ensino simultâneo de três relações condicionais, o que é importante para eficiência de ensino e evitar o estabelecimento de topografias de controle de estímulos irrelevantes. A discussão aborda questões acerca dos procedimentos e da programação de ensino de relações condicionais e identidade generalizada para indivíduos com atraso no desenvolvimento. Palavras-chave: procedimento blocado; discriminação condicional de identidade; identidade generalizada; autismo

CONTROLES POR SELEÇÃO E REJEIÇÃO EM TREINOS DE DISCRIMINAÇÃO CONDICIONAL E TESTES DE EQUIVALÊNCIA

Falhas na formação de classes de estímulos equivalentes têm sido explicadas, ocasionalmente, em função dos controles de estímulo (ou topografias de controle de estímulo) que ocorrem ao longo dos treinos de discriminação condicional e nos testes de equivalência. O presente artigo pretende apresentar, didaticamente, as implicações de dois controles de estímulo particulares, o de escolha por seleção do estímulo programado como S+ e o de rejeição daquele programado como S- sobre a formação de classes de estímulos equivalentes em tarefas de matching-to-sample (MTS) envolvendo dois estímulos de comparação. Para tanto, é apresentada, após uma breve revisão da literatura de equivalência, a análise teórica de Carrigan e Sidman (1992), bem como resultados experimentais que a dão suporte. Por fim, dados de pesquisas recentes são discutidos frente a possíveis propostas de investigação que isolariam experimentalmente o estabelecimento de diferentes controles de estímulo.Palavras-chave: topografias de controle de estímulo, controle por seleção, controle por rejeição, equivalênciade estímulos, matching to sample.

RESPONDER POR EXCLUSÃO A PARTIR DE UMA LINHA DE BASE DE DISCRIMINAÇÕES CONDICIONAIS VISUAIS

Este trabalho investigou o responder de escolha por “exclusão”, fenômeno comportamental robusto, demonstrado experimentalmente pela seleção imediata de um estímulo de comparação indefinido, diante de um estímulo modelo também indefinido experimentalmente, sem uma história prévia que torne o estímulo de comparação discriminativo para a resposta de seleção. A exclusão tem sido extensamente replicada com uma preparação experimental de linha de base de discriminações condicionais auditivo-visuais. O presente estudo investigou a ocorrência da exclusão quando apenas estímulos visuais são utilizados como modelos e comparações. Dois experimentos empregaram os mesmos arranjos experimentais dos estudos prévios, substituindo os modelos auditivos pelos visuais, com a linha de base para os testes de exclusão envolvendo um mesmo modelo relacionado a vários estímulos de comparação (Experimento I) ou vários modelos relacionados a um mesmo estímulo de comparação (Experimento II). Nove crianças de 4 a 5 anos foram expostas à seguinte seqüência experimental: (a) estabelecimento de uma linha de base de discriminações condicionais visuais um para um; (b) testes de exclusão; (c) ampliação da linha de base pelo ensino de discriminações condicionais inter-relacionadas; (d) novos testes de exclusão; e (e) testes de formação de classes de estímulos. Todos os participantes adquiriram as discriminações condicionais e apresentaram o responder por exclusão e a formação de classes de equivalência. Esses resultados estendem as descobertas sobre a escolha por exclusão, demonstrando que não é dependente do envolvimento da modalidade auditiva, e fortalecem a noção de que esse comportamento emergente tem origem nos mesmos processos básicos envolvidos na formação de classes de equivalência. Palavras-chave: exclusão, comportamento emergente, discriminação condicional, topografia de controle de estímulos, controle por seleção, controle por rejeição

VARIÁVEIS DE PROCEDIMENTO NA PESQUISA SOBRE CLASSES DE EQUIVALÊNCIA: CONTRIBUIÇÕES PARA O ESTUDO DO COMPORTAMENTO SIMBÓLICO

Os procedimentos tipicamente usados em Análise Experimental do Comportamento para estudar a formação de classes de equivalência podem constituir um modelo experimental para estudar o comportamento simbólico. A formação de classes de equivalência e o comportamento simbólico têm em comum o fato de elementos dissimilares, uma vez arbitrariamente relacionados, se tornaram equivalentes, ou seja, se tornaram substituíveis no que diz respeito ao controle de repertórios a eles associados. Dificuldades para obtenção de classes de equivalência com organismos nãolingüísticos têm levado à especulação de que a formação de classes de equivalência, e possivelmente o comportamento simbólico, seja um fenômeno dependente de funcionamento lingüístico. Alguns trabalhos relatados na literatura, contudo, sugerem que as dificuldades de obtenção de classes de equivalência com organismos não-lingüísticos podem decorrer da falha dos procedimentos para efetivamente treinar as relações de controle planejadas pelo experimentador. O presente trabalho apresenta uma breve revisão de conceitos básicos sobre relações de equivalência, discute algumas das possibilidades de desenvolvimento de controle incoerente em estudos sobre equivalência e aponta brevemente alguns estudos sobre procedimentos alternativos para selecionar relações de controle coerentes com as relações experimentalmente planejadas. Palavras-chave: classes de equivalência, comportamento simbólico, topografia de controle de estímulos, comportamento animal.

Comments on Sidman’s Remarks Series

(2011). Comments on Sidman’s Remarks Series. European Journal of Behavior Analysis: Vol. 12, No. 1, pp. 339-341.

Varieties of Stimulus Control in Matching-to-Sample: A Kernel Analysis

Conditional discrimination or matching-to-sample procedures have been used to study a wide range of complex psychological phenomena with infrahuman and human subjects. In most studies, the percentage of trials in which a subject selects the comparison stimulus that is related to the sample stimulus is used to index the control exerted by the relation between the stimuli. Performances indexed by percentage correct based on an aggregation across single trials, however, cannot identify the stimulus control topographies that exert momentary control of responding in a matching-to-sample milieu. The behavioral kernel is a unit of analysis that can provide such a measure. When a two-choice matching-to-sample procedure is used, analysis in terms of behavioral kernels permits the measurement of 16 potential stimulus control topographies. The kernel analysis provides the potential of assessing the many stimulus control topographies that control performances on a transient basis prior to the emergence of experimenter-specified conditional discriminative control. This sort of analysis could clarify the behavioral processes involved in the formation of learning set and problem-solving strategies when subjects are faced with complex discriminations, as well as the variables that influence these phenomena. As such, it is also related to accounts of discrimination learning as addressed by error-factor theory, hypothesis-based learning, and stimulus control topography coherence theory. Finally, a kernel analysis could also be used to

Equivalence class formation in a trace stimulus pairing two-response format: effects of response labels and prior programmed transitivity induction.

Three experiments identified factors that did and did not enhance the formation of two-node four-member equivalence classes when training and testing were conducted with trials presented in a trace stimulus pairing two-response (SP2R) format. All trials contained two separately presented stimuli. Half of the trials, called within-class trials, contained stimuli from the same class while the other half, called cross class trials, contained stimuli from different classes. On within class trials, making a YES response was correct and making a NO response was wrong. On cross class trials, making a NO response was correct and making a YES response was wrong. In Experiment 1, similar intermediate percentages of participants (about 50%) formed classes, regardless of whether the responses were labeled YES and NO or SAME and DIFF. Response labeling thus did not influence class formation. Regardless of response labels, failures of class formation were primarily due to failure of class-indicative responding produced by within-class transitivity probes. In Experiment 2, only 50% of participants formed classes without prior training, as in Experiment 1, but 100% of participants formed equivalence classes after the establishment of a generalized transitivity repertoire by use of a programmed transitivity induction protocol. Experiment 3 examined two components of the programmed transitivity induction protocol and found that the exclusion of AC trials had no effect on the percentage of participants who formed equivalence classes, while presenting the stimulus sets in randomized order interfered with equivalence class formation. A further analysis found that a number of stimulus control topographies differentiated between individuals who did and did not form equivalence classes. In general, then, these experiments demonstrate that equivalence classes can be formed reliably when training and testing are conducted in an SP2R format, supporting the view that equivalence class formation can account for the development of conceptual categories in natural settings.

The search for symmetry: 25 years in review.

It has been 25 years since the publication of Sidman et al.'s (1982) report on the search for symmetry in nonhuman animals. They attributed their nonhuman subjects' failure to the absence of some critical experiences (e.g., exemplar training, control of location variables, and generalized identity matching). Since then, species ranging from rats to chimpanzees have been tested on symmetry, and the results have been equivocal. Twenty-four investigations of symmetry in nonhumans are reviewed to determine whether the underlying factors first addressed by Sidman et al. (1982) have been verified and whether new factors have been identified. The emergent picture shows that the standard procedures as typically implemented on a three-key apparatus are insufficient by themselves to produce emergent symmetry in nonhumans. Recent successful demonstrations of symmetry in sea lions and pigeons have clarified certain important stimulus control variables (i.e., select and reject control) and suggest avenues for future research. Reliable symmetry may be achievable with nonhumans if training and test procedures that encourage compatible stimulus-control topographies and relations are designed.

Stimulus control topography coherence theory: Foundations and extensions

Stimulus control topography refers to qualitative differences among members of a functional stimulus class. Stimulus control topography coherence refers to the degree of concordance between the stimulus properties specified as relevant by the individual arranging a reinforcement contingency (behavior analyst, experimenter, teacher, etc.) and the stimulus properties that come to control the behavior of the organism (experimental subject, student, etc.) that experiences those contingencies. This paper summarizes the rationale for analyses of discrimination learning outcomes in terms of stimulus control topography coherence and briefly reviews some of the foundational studies that led to this perspective. We also suggest directions for future research, including pursuit of conceptual and methodological challenges to a complete stimulus control topography coherence analysis of processes involved in discriminated and generalized operants.

Predicting Taxonomic and Thematic Relational Responding

Pairs of pictures were classified by the authors and others as related by identity (A-A), basic taxonomy (A-B), superordinate taxonomy (A-C), or by theme (A-D). Two-choice matching-to-sample trial types were composed of these same picture pairs in which the sample was common to the two stimulus pairs in each configuration and, together with the sample, each comparison exemplified one of the relations in the picture pair; that is: A(AB), A(AC), A(AD), A(BC), A(BD), and A(CD). In five experiments, for each picture pair, college students classified the relation (as taxonomic or thematic) and rated its strength (Exps 1, 3) or its similarity (Exp 4); others matched to sample the foregoing trial types only (Exps 2, 5), or they classified and rated, too (Exp 3). With exceptions, students classed most pairs as the authors did. They also collectively ordered relational strengths from (1) identity, (2) basic taxonomy, and (3) theme, to (4) superordinate taxonomy based, in part, on the similarity of sample and comparison. Subjects chose the comparisons of the more strongly related picture pairs in the matching-to-sample task on 90 percent or more of the configurations. Subjects' selections in two-choice, matching-to-sample configurations using natural stimuli may be based on existing stimulus control topographies such as those exhibited by ratings of the relations in a configuration.

High-probability stimulus control topographies with delayed S+ onset in a simultaneous discrimination procedure.

Experimenters and teachers use discrimination learning procedures to encourage reliable attending to stimulus differences defined as relevant for their purposes. Put another way, the goal of discrimination training is to establish high-probability stimulus control topographies that are coherent with experimenter or teacher specifications. The present research was conducted to investigate a novel procedure for encouraging stimulus control topography coherence. Participants were 13 adolescents with severe intellectual handicaps. During an initial Condition A, all were exposed to a simultaneous discrimination procedure. Participants could select a form alternating with a black field (S+) or an identical form that did not alternate (S-). Accuracy scores were typically low, and there was little evidence of coherent stimulus control topographies. Subsequently, the procedure was changed. During Condition B, every trial initially presented two identical nonalternating S- forms (Trial State 1). If the participant made no selection for 5 s, one of the forms began to alternate with the black field, and he or she could make the S+/S- discrimination (Trial State 2). Selections during Trial State I prolonged the delay to Trial State 2 until there had been no response for 5 s. During Condition B, S+/S- discrimination accuracy scores improved rapidly and markedly for most participants. Reinstating Condition A often resulted in diminished accuracy scores. This study thus (a) demonstrated a novel procedure for encouraging stimulus control topography coherence and (b) provided support for the interpretation that intermediate accuracy scores may be due to different topographies of stimulus control that co-occur in the same discriminative baseline.

Behavioral momentum and multiple stimulus control topographies

We have analyzed many discrimination learning difficulties as reflecting multiple stimulus control topographies (SCTs). Nevin & Grace's analysis offers new variables to consider in the design of stimulus-control shaping procedures and cross-setting generalization of newly established behavior. A multiple-SCT perspective also suggests that fixed-trial discrimination procedures may offer advantages for reconciling momentum theory and partial reinforcement extinction effects.

On Terms and Procedures: Fluency

Fluency is a metaphor for flowing, effortless, well-practiced, and accurate performance. Current practice in fluency building involves increasing the frequency of free-operant performances. Free-operant performance is defined as continuous responding in the presence of discriminative stimuli that are either varied or not varied from response to response. Free-operant performance is also distinguished from discrete-trial performance. Frequency-building procedures are also described, including defining the learning channel and stimulus control topography of a component performance (called a pinpoint), selecting an appropriate timing period, and displaying stimuli so that no performance ceilings occur. During frequency building, frequencies of pinpoints are continuously charted on standard celeration charts. Frequencies are increased to empirically derived performance standards, or aims, that predict retention, endurance, stability, application, and adduction of performance. Frequency is also described as a dimension of performance, not simply its measurement. Frequency building is described as possibly facilitating contingency adduction.