Equivalence classes in individuals with minimal verbal repertoires

The Problem of Class Breakdown in Sidman's (1994, 2000) Theory about the Origin of Stimulus Equivalence

Sidman (1994, 2000) hypothesized that equivalence relations are a direct outcome of reinforcement contingencies. This theory is problematic because contingencies do not always result in equivalence. Sidman proposed that equivalence relations may conflict with analytic units, the other outcome of contingencies (e.g., in conditional discriminations with common responses/reinforcers). This conflict may result in a generalized class breakdown and a failure to pass equivalence tests. This is more likely in nonhumans, very young humans, etc. The conflict can also result in a selective class breakdown and success in equivalence tests. This occurs after experience shows the organism the necessity and utility of this process. The nature of that experience and the class breakdown processes were not described by Sidman. I explored the implications of the following hypotheses for Sidman's theory. First, conditional discriminations with a common response/reinforcer result in a generalized class breakdown when participants fail to discriminate emergent relations incompatible with contingencies from those compatible. Second, learning to discriminate between the two requires a history of multiple exemplar training (MET). This implies that equivalence class breakdown is a common response to exemplars that have nothing in common except their relations. This, however, contradicts Sidman's views about the impossibility of such process in the absence of a complex verbal repertoire. If that type of learning from MET is possible, then the possibility that MET results in the selective formation of equivalence classes must be admitted, and the utility of hypothesizing that equivalence is a direct outcome of reinforcement contingencies can be questioned.

Verbal behavior development theory and relational frame theory: Reflecting on similarities and differences

Relational frame theory and verbal behavior development theory are two behavior-analytic perspectives on human language and cognition. Despite sharing reliance on Skinner's analysis of verbal behavior, relational frame theory and verbal behavior development theory have largely been developed independently, with initial applications in clinical psychology and education/development, respectively. The overarching goal of the current paper is to provide an overview of both theories and explore points of contact that have been highlighted by conceptual developments in both fields. Verbal behavior development theory research has identified how behavioral developmental cusps make it possible for children to learn language incidentally. Recent developments in relational frame theory have outlined the dynamic variables involved across the levels and dimensions of arbitrarily applicable relational responding, and we argue for the concept of mutually entailed orienting as an act of human cooperation that drives arbitrarily applicable relational responding. Together these theories address early language development and children's incidental learning of names. We present broad similarities between the two approaches in the types of functional analyses they generate and discuss areas for future research.

Effective use of the blank comparison procedure in simple discrimination by infant capuchin monkeys: A methodological note

In studies of simple and conditional discrimination, procedures are needed to measure those aspects of stimuli that control behavior. The blank comparison procedure is one such procedure. It was designed explicitly for assessing S+ and S- functions when discriminative stimuli are presented simultaneously. In this procedure, a neutral stimulus serves sometimes as S+ and sometimes as S-. Its discriminative function is defined in relation to other stimuli in the display. The present study aimed to prepare 2 infant female capuchin monkeys for the effective use of the blank comparison procedure in a simple discrimination task. First, simple discrimination training was applied up to a stable accuracy criterion of ≥90%. This training was followed by the replacement of S+ and then of S- stimuli with new stimuli. Ultimately, trials with the blank comparison were introduced. Following this sequence, both monkeys immediately displayed highly accurate blank-comparison performances without the need for stimulus control shaping or other preparatory discrimination training. Thus, this procedure sequence may be an efficient, effective method for establishing blank-comparison baselines for experimental analyses of S+/S- discriminative functions and perhaps for other applications in teaching simple and conditional discrimination performances to this species and others.

Naming of Stimuli in Equivalence Class Formation in Children

In the present study, two typically developing 4-year-old children, Pete and Joe, were trained six conditional discriminations and tested for the formation of three 3-member equivalence classes. Pete and Joe did not establish the AC relation within 600 trials and were given two conditions of preliminary training, including naming of stimuli with two different stimulus sets. Pete started with preliminary training with common naming of stimuli, followed by conditional-discrimination training and testing for emergent relations, and continued with preliminary training on individual naming of stimuli, followed by the same training and testing as described previously. Joe experienced the same conditions but in reversed order. Pete responded in accordance with equivalence in the second round in the condition with common naming. In the first round of testing in the condition with individual naming, he responded in accordance with equivalence. In the condition with individual naming, Joe did not respond in accordance with stimulus equivalence but established all of the directly trained relations during training. In the condition with common naming, he responded in accordance with equivalence in the first round of testing. The results from the experiment support earlier findings that both common and individual naming could facilitate the emergence of equivalence classes.

Efectos de variar la presentación de las instrucciones en la Tarea Torre de Londres

El efecto de las instrucciones sobre la conducta de los sujetos en situaciones experimentales ha sido un tema de interés en el análisis de la conducta. La variación de su contenido, como la especificidad y la precisión, son factores que han mostrado tener efectos sistemáticos en la adquisición de comportamientos complejos en periodos breves de tiempo. Se ha especulado que el aprendizaje observacional puede ser considerado, funcionalmente, como una instancia del control instruccional. En esta medida, es de interés comparar esta modalidad de instrucción con instrucciones escritas en una situación de laboratorio. El objetivo de este estudio fue evaluar los efectos de variar la presentación de las instrucciones en: 1) instrucciones escritas 2) una demostración visual y 2) una demostración visual más regla de operación; utilizando la tarea de la torre de Londres. Se utilizó un diseño de grupo. Participaron treinta adultos y treinta niños, seleccionados por un muestreo no probabilístico. Los resultados mostraron que, tanto para niños como adultos, el grupo con instrucciones leídas tuvo un incremento en las respuestas correctas durante las pruebas de transferencia mientras que, en las otras condiciones, las respuestas correctas bajaron en estas fases. Por otro lado, los reportes verbales sobre la ejecución de la tarea se ubicaron en un nivel concreto y hubo poca correspondencia entre el efecto de las instrucciones y el reporte verbal de los participantes. Se concluye, señalando la necesidad de más experimentación enfocada en analizar la naturaleza de la tarea experimental.

Equivalence Class Formation in Individuals With Autism: Predictions From ABLA-R Levels

Children who are diagnosed with autism spectrum disorder (ASD) often fail to show equivalence class formation. This may be related to their difficulty in learning the programmed baseline conditional discriminations. The present study investigated equivalence class formation after training visual identity-matching performance with auditory class-specific consequences in 6 individuals who were diagnosed with ASD and who achieved different levels (Levels 4, 5, and 6) on the Assessment of Basic Learning Abilities-Revised (ABLA-R). The potentially emergent relations were all arbitrary (relations between completely dissimilar stimuli): visual-visual (AB and BA) and auditory-visual (SA and SB). None of the participants who achieved ABLA-R Level 4 or 5 responded in accord with equivalence class formation. They did not present any emergent arbitrary conditional relations (either visual-visual relations or auditory-visual relations). Only participants who achieved ABLA-R Level 6 demonstrated equivalence class formation. These findings are consistent with the predictive ability of the ABLA-R with regard to the acquisition of discriminations and to the emergence of the same type of conditional relations and the same hierarchy of complexity.

An update on the search for symmetry in nonhumans

Sidman et al.'s (1982) failure to find evidence for symmetry (bidirectional associations between stimuli) in monkeys and baboons set the stage for decades of work on emergent relations in nonhumans. They attributed the failure to the use of procedures that did not (1) promote stimulus control based on the relation between the sample and correct comparison and (2) reduce control by irrelevant stimulus features. Previous reviews of symmetry in nonhumans indicated that multiple exemplar training and successive matching might encourage appropriate stimulus control. This review examined 16 studies that investigated symmetry in 94 subjects, including pigeons, rats, capuchin monkeys, and baboons. Several studies used alternative training procedures to minimize sources of irrelevant stimulus control, and many combined multiple exemplar training with other procedural modifications. Symmetry was observed in approximately 30% of subjects. Studies that reported the strongest evidence for symmetry used successive matching-to-sample procedures that included training on both symbolic and identity relations, and studies finding mixed evidence employed alternative methods. These studies highlight the challenge in creating training procedures that promote symmetry and the need to assess the underlying sources of control on positive demonstrations.

Model Dependent Realism and the Rule-Governed Behavior of Behavior Analysts: Applications to Derived Relational Responding

A fundamental assumption within radical behaviorism is that all human behavior, including the rule-governed behavior of scientists, can be understood within a functional account. I propose that models of human behavior can be best described as a set of rules that are selected by behavior analysts to solve applied challenges, rather than descriptions of nature as it "truly exists." Model dependent realism (MDR) developed within the field of physics may provide useful criteria that could allow behavior analysts to more accurately track the relative probability of success of a given model within applied contexts. As a case example, I examine dispersive models of derived relational responding in terms of the criteria outlined within MDR, and I describe a preliminary level-scaling account of derived relational responding that encompasses several models in pursuit of a unified account. The account is context dependent and adopts a pragmatic truth criterion, consistent with assumptions within functional contextualism and radical behaviorism as an overarching rule governing the behavior of our applied subfield.

Establishing arbitrary comparative relations and referential transformations of stimulus function in individuals with autism

Relational Frame Theory posits that complex language develops through arbitrarily applicable relational networks, with potential implications for individuals with autism. Responding relationally based on comparison occurs when participants respond to any number of comparative properties, such as "bigger" or "faster." Experiment 1 established two 3-member comparative networks, in which a stimulus A was conditioned as "bigger" or "faster" than a stimulus B, and the stimulus B was conditioned as "bigger" or "faster" than a stimulus C in 2 children with autism. Both participants met the mastery criterion for the trained relations and demonstrated the emergence of the untrained combinatorially entailed A-C and C-A relations. The participants could also match the arbitrary A stimuli with larger or faster objects and the C stimuli with smaller or slower objects. The results were replicated in Experiment 2 with the same participants, where a 5-member relational network was established for the bigger/smaller relation.

Transfer of baseline reject control to transitivity trials and its effect on equivalence class formation

This study explored the role of baseline reject control on transitivity responding. In Experiment 1, participants learned to respond to a baseline of arbitrary AB and AC conditional relations, and then they were exposed to transitivity-like BC and CB trials in which the correct comparison stimulus was replaced by a novel stimulus (D). Five of 10 participants selected stimulus D, but only 1 showed expansion of the baseline stimulus classes to include the D stimuli. In Experiment 2, the emergence of symmetry and transitivity from baseline relations was assessed before participants were exposed to the transitivity-like trials. Six of 8 participants who showed emergence of equivalence relations selected the D stimuli on transitivity-like trials and provided evidence that baseline classes expanded to include these stimuli. In Experiment 3, these 6 participants selected novel stimuli (E) in additional transitivity-like trials, and all showed that the E stimuli had become members of the previously established classes, which now comprised 5 members. A route for the emergence of transitivity by way of the transfer of baseline between-classes reject control is discussed.

EXCLUSION LEARNING AND EMERGENT SYMBOLIC CATEGORY FORMATION IN INDIVIDUALS WITH SEVERE LANGUAGE IMPAIRMENTS AND INTELLECTUAL DISABILITIES

We evaluated formation of simple symbolic categories from initial learning of specific dictated word-picture relations through emergence of untaught or derived relations. Participants were 10 individuals with severe intellectual and language limitations. Three experimental categories were constructed, each containing 1 spoken word (Set A), 1 photograph (Set B), and 1 visual-graphic "lexigram" (Set C). Exclusion-based learning procedures were used to teach first the 3 auditory-visual relations (A-B relations) and then the 3 visual-visual relations (B-C relations) for each category. Seven participants acquired these initial relations. The untaught relations C-B and A-C were then assessed to evaluate the emergence of symbolic categories. Participants demonstrated virtually error-free performances on C-B and A-C derived relations. The study helps to define operationally a highly useful procedural path for systematic instruction in symbolic functioning for persons with intellectual and language disabilities associated with autism and other neurodevelopmental disorders.

Variables affecting the emergence of untaught equivalence relations in children with and without autism

OBJECTIVE

This study examined the formation of equivalence classes among children with ASD and typically developing children.

DESIGN

A single-subject AB and BA design was used.

METHODS

Two of the six equivalence relations were taught. Participants were then tested to determine whether the remaining four equivalence relations were acquired without teaching. Half of the children were taught naming responses first, then selecting responses. Half were taught in the reverse order.

RESULTS

Five out of 10 participants with ASD demonstrated the emergence of all four untaught relations. The remaining five participants showed variability. Nine of the 10 typically developing children demonstrated emergence of all untaught relations. Variation in teaching conditions had no significant effect on outcomes.

CONCLUSIONS

Many children with ASD are capable of generalising to untaught equivalence relations. The results fail to support the claim that acquisition of naming responses is a pre-requisite for the emergence of untaught equivalence relations.

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.

Teaching Stimulus-Stimulus Relations to Minimally Verbal Individuals: Reflections on Technology and Future Directions

This paper discusses recent methodological approaches and investigations that are aimed at developing reliable behavioral technology for teaching stimulus-stimulus relations to individuals who are minimally verbal and show protracted difficulty in acquiring such relations. The paper has both empirical and theoretical content. The empirical component presents recent data concerning the possibility of generating rapid relational learning in individuals who do not initially show it. The theoretical component (1) considers decades of methodological investigations with this population and (2) suggests a testable hypothesis concerning some individuals exhibit unusual difficulties in learning. Given this background, we suggest a way forward to better understand and perhaps resolve these learning challenges.

Apraxia e produção da fala: efeitos do fortalecimento de relações verbais

Este estudo propõe relatar o efeito do fortalecimento de relações de leitura e da transferência de controle de estímulos sobre a produção da fala de uma criança com apraxia de fala. Utilizou-se o programa Aprendendo a Ler e a Escrever em Pequenos Passos(r). As atividades foram realizadas em 22 sessões, com duas sessões semanais, de 30 minutos cada. Como resultados houve aumento na porcentagem de acertos na produção da fala do participante frente a diferentes estímulos. Os resultados corroboram os estudos anteriores sobre o favorecimento da fala por meio de relações de equivalência e dados sobre o benefício do trabalho a partir do fortalecimento da rede de leitura e escrita.

Efeitos de ensino envolvendo equivalência entre palavra ditada, palavra escrita e objeto sobre a inteligibilidade da fala em adolescente com hipoplasia cerebelar

Dentre as muitas estruturas cerebrais envolvidas na linguagem, o ceberelo cumpre um papel importante na coordenação dos movimentos responsáveis pela fala, de modo que qualquer alteração nesta estrutura pode comprometer o desenvolvimento da linguagem oral. Considerando o planejamento do ensino e as intervenções enquanto um fator que pode alterar as expressões fenotípicas impostas pela hipoplasia cerebelar, este estudo de caso teve como objetivo verificar os efeitos de um programa de ensino (envolvendo equivalência entre palavra ditada, palavra escrita e objeto) sobre a inteligibilidade da fala de um adolescente com doze anos, gênero masculino, com hipoplasia cerebelar. As sessões foram conduzidas em contexto clínico e com uso de brinquedos de preferência do participante. O programa consistiu em etapas de avaliação, ensino, pós-testes e retenção, no qual eram apresentadas tarefas de seleção, vocalização, escrita e composição de palavras. Durante a avaliação, observou-se um baixo desempenho em todas as tarefas, especialmente na nomeação de objetos; no decorrer do ensino, as vocalizações foram monitoradas, constatando-se uma gradativa melhora na inteligibilidade da fala quando o participante nomeava objetos, chegando à precisão no pós-testes e retenção. Pode-se concluir que, para o caso apresentado, o fortalecimento da rede de relações entre estímulos e estímulos-ações verbais promovido pelo programa de ensino, favoreceu melhorias na inteligibilidade da fala.

Transitive and anti-transitive emergent relations in pigeons: support for a theory of stimulus-class formation

Stimulus class formation is inferred when conditional discrimination training yields new (emergent) conditional relations between the training stimuli. The present experiments demonstrated two such relations in pigeons after successive matching-to-sample training. Experiment 1 showed that transitivity (AC matching) emerged after training on AB and BC arbitrary matching plus BB identity matching: pigeons responded relatively more to the comparisons on AC test trials in which both the A samples and C comparisons were elements of reinforced arbitrary baseline relations involving the same nominal B stimulus. Experiment 2 showed the opposite effect ("anti-transitivity") after training on the same arbitrary relations but with BB oddity instead: pigeons responded relatively more to the comparisons on AC test trials in which the A sample was an element of a reinforced baseline relation and the C comparison was an element of a non-reinforced baseline relation, or vice versa. Experiment 2 also showed that AB and BC training alone generally does not yield an emergent effect. These findings extend the range of emergent phenomena observed in non-human animals and are consistent with predictions from Urcuioli's (2008) theory of pigeons' stimulus class formation. This article is part of a Special Issue entitled: Tribute to Tom Zentall.

Controlling Relations in Stimulus Equivalence Classes of Preschool Children and Individuals with Down Syndrome

We evaluated emergent stimulus-stimulus relations after two different training procedures. Participants were five typically developing preschool children and three individuals with Down Syndrome. Experiment 1 used two-comparison matching to sample (MTS) to establish AB and BC relations. Experiment 2 used two-comparison and blank-comparison MTS, each on 50% of training trials to establish AB and BC relations. In both experiments, tests for emergent relations (AC, CA) were conducted to assess equivalence class formation. In Experiment 2 subsequently, class expansion was assessed after CD training. All participants showed positive equivalence test outcomes. Seven showed class expansion. After class formation tests in both studies, probe tests were conducted for select and reject relations in baseline relations. Initial results were somewhat variable, but became more consistent after class expansion.

Blank-comparison matching-to-sample reveals a false positive symmetry test in a capuchin monkey

A positive symmetry test result was obtained with a capuchin monkey that had previously exhibited virtually errorless AB and BA arbitrary matching-to-sample (MTS) with different stimuli. The symmetry test (BA) followed the acquisition of a new AB relation. It seemed possible, however, that the positive result could have occurred through the exclusion of previously defined comparison stimuli and not because the new AB and BA relations had the property of symmetry. To assess this possibility, a blank-comparison MTS procedure was implemented that permitted the separate assessment of select and reject (i.e., exclusion) control with both baseline and BA matching relations. In this assessment, the monkey did not exhibit reliable BA matching when exclusion was not possible, thus showing that the symmetry result was a false positive. However, the study demonstrated the feasibility of using a blank comparison MTS procedure with capuchins. The present results may set the stage for more successful methodology for establishing desired forms of relational stimulus control in capuchins and ultimately improving the assessment of relational learning capacity in that species, other nonhuman species, and nonverbal humans.

Cross-modal transitivity in a California sea lion (Zalophus californianus)

The ability of an experimentally experienced female California sea lion to form transitive relations across sensory modalities was tested using a matching-to-sample procedure. The subject was trained by trial-and-error, using differential reinforcement, to relate an acoustic sample stimulus to one member from each of two previously established visual classes. Once the two auditory-visual relations were formed, she was tested to determine whether untrained transitive relations would emerge between each of the acoustic stimuli and the remaining stimuli of each 10-member visual class. During testing, the sea lion demonstrated immediate transfer by responding correctly on 89% of the 18 novel transfer trials compared to 88% on familiar baseline trials. We then repeated this training and transfer procedure twice more with new auditory-visual pairings with similar positive results. Finally, the six explicitly trained auditory-visual relations and the 56 derived auditory-visual relations were intermixed in a single session, and the subject's performance remained stable at high levels. This sea lion's transfer performance indicates that a nonhuman animal is capable of forming new associations through cross-modal transitivity.

Behavior analysis, relational frame theory, and the challenge of human language and cognition: A reply to the commentaries on relational frame theory: A post-skinnerian account of human language and cognition

Answers to a series of commentaries are presented and the challenge Relational Frame Theory (RFT) presents to behavior analysis is explicated. RFT is a behavior analytic theory, based on extensive behavior analytic data, which appeals only to known principles to explain arbitrarily applicable relational responding. The claim that such responding is operant must be answerable within behavior analysis. RFT has too much empirical support for the field to avoid this challenge. If the answer is "yes," behavior analysis seems destined to enter a new era.

A stimulus in need of a response: A review of relational frame theory: A post-skinnerian account of human language and cognition

In this commentary, I describe relational frame theory (RFT) as an analysis of complex human behavior that has been insufficiently addressed within contemporary behavior analysis. The theory is described as having an exceptionally ambitious vision of the type that will render behavior analytic accounts more generally acceptable within the broader behavioral and cognitive sciences. In my own view, inductive empirically-driven analyses derived from current data on relational learning (including my own) have not been comparably ambitious; they have not addressed the full range of phenomena to which they might be profitably applied. By contrast, researchers in the RFT tradition have ambitious; they have not addressed the full range of phenomena to which they might be profitably applied. By contrast, researchers in the RFT tradition have tended to project their analyses to encompass a variety of plausible, attractive applications that are arguably within the reach of their current data or data that may be reasonably anticipated in the future. In order for RFT researchers to have its maximum impact, however, I suggest that certain critical steps must be accomplished. First, the theory must be reconciled with the basic behavioral processes that are the core of the experimental analysis of behavior. Second, certain experiments must be conducted that have thus far not been emphasized in the RFT tradition. In particular, I suggest that the current practice of studying college students and verbal school-aged children must be supplemented with comparably intensive studies of populations with developmental limitations (e.g., typically developing children who are just acquiring language). Absent such experimentation, it seems likely that RFT will remain a plausible account that merely competes with other plausible accounts without promoting ultimate resolution of the critical issues.