Stimulus Equivalence Classes Research Articles

Transfer of “S+” and “S-” Functions in Stimulus Equivalence Classes

This study compared results of two experiments that tested transfer of function in stimulus equivalence classes in a task dissimilar to (in Experiment I) and similar to (in Experiment II) the task that trained functional responding. Eleven students from the University of North Texas participated in return for monetary compensation. Phase 1 and 2 were identical in the two experiments, in which they established stimulus equivalence classes and functional responding, respectively. Each experiment then used different tasks in the third phase to test differential responding. Only participants in Experiment II demonstrated consistent transfer of function. Results are discussed in terms of how task similarity may function as a type of contextual control when there is limited experience with the task.

The Effects of Common Names and Common FR Responses on the Emergence of Stimulus Equivalence Classes

The objective of the present set of studies was compare two procedures for facilitating the emergence of equivalence classes in college students. In Experiment 1, which used a within-group design, participants in one condition were first taught to give class-consistent names to the stimuli which would subsequently be conditionally related. In the second condition participants were first taught to emit common fixed ratio responses in the presence of stimuli which would subsequently be conditionally related. After this training, participants completed conditional discrimination training followed by equivalence testing. Results suggested that the name and FR condition were equally effective in facilitating the emergence of equivalence classes. Experiment 2, which used a between-group design, was similar to Experiment 1 except that participants were asked to “talk aloud” during conditional discrimination training and the stimulus equivalence test. Experiment 2 also employed a control group, who received no common response training. In general, the findings from both experiments suggest that names are not necessary for the formation of equivalence classes, and training common nonverbal responses may be equally effective in promoting class formation.

Transfer of Function through Equivalence Relations using Pictures with Strong Emotional Content

To simulate the emotional judging function seen in some clinical problems, matching-to-sample training was used to establish three-member stimulus equivalence classes consisting of abstract paintings. Pictures with strongly positive or negative emotional content were then paired with only one of the paintings in each class, and transfer of the judgement function to the other stimuli in the equivalence class was tested. A single-case, multi-element pretest-posttest design was used with 10 participants in each of two experiments. Stimulus equivalence emerged in all participants, with 95%-100% correct responses. However, transfer of the judgement rating function appeared consistently in only three participants in Experiment 1. In Experiment 2, transfer test trials were done only in the posttest phase to obviate the effects of pre-experimental history, preference or memory, but only two participants consistently showed transfer. We conclude that the experimental method we used controls for procedural variables that might account for the between-participant and within-stimulus variability usually found in earlier transfer experiments. In contrast to the appearance of stimulus equivalence, the emergence of transfer of function did not appear to be an automatic process.

Stimulus Relatedness in Equivalence Classes: Interaction of Nodality and Contingency

Stimuli in equivalence classes are functionally interchangeable, and thus suggest that the class members are equally related to each other. A growing number of experimental findings, however, have shown that under appropriate conditions of testing, the relational strength of the stimuli in an equivalence class may be determined by the nodal structure of the class and the number of nodes the separate the stimuli in a multinodal class. Data that support this view have been obtained (a) during the delayed emergence of classes, (b) during gradual transfer of functions after class formation, (c) from the reaction times displayed by derived relations that varied in nodal number during and after class formation, (d) by derived relations in the absence of class formation, (e) from retrospective reports of reinforcer presentations during derived relations probes, (f) from brain imaging studies that showed unique areas of cortical activation produced by post-class formation probes of baseline and derived relations, (g) within class preference tests that pitted relations of different nodal numbers, and (g) the results of response transfer tests that bifurcated multinodal equivalence classes in precise accordance with nodal structure. Taken together, the data suggest that the stimuli in an equivalence class acquire two functions: one class based, and the other nodally based. Performances reflective of each are under the discriminative control of test trials that had different formats. When the format signals the primacy of between-class variables, only one response option is available per class, and the stimuli in the class produce responding indicative of the interchangeability, and the equal relatedness of the stimuli in the class. When the trial format signal the primacy of within-class variables, at least two response options are available per class, and the stimuli and relations produce differential responding that are inverse functions of nodality which indicate the unequal relatedness of the stimuli in the class.

CONTEXTUAL CONTROL BY FUNCTION AND FORM OF TRANSFER OF FUNCTIONS

This study investigated conditions leading to contextual control by stimulus topography over transfer of functions. Three 4-member stimulus equivalence classes, each consisting of four (A, B, C, D) topographically distinct visual stimuli, were established for 5 college students. Across classes, designated A stimuli were open-ended linear figures, B stimuli were circular, C stimuli three-sided, and D stimuli four-sided. Three different computer tasks then were trained with the B stimuli. Differential reinforcement and punishment procedures were then used to establish control over function transfer by the topography of the class members. For Task 1, function transfer, responding to C and D stimuli as subjects had to B stimuli, was reinforced. For Task 2, function transfer was reinforced for C stimuli but punished for D stimuli. For Task 3, function transfer was punished for both C and D stimuli. New equivalence classes were then established and tests for generalized contextual control were presented. All 5 subjects showed generalized contextual control of transfer of functions by stimulus topography. Implications of contextual control over function transfer in natural settings are discussed.

Emergência conjunta dos comportamentos de ler e escrever palavras e identificar números após o ensino em separado desses repertórios

Doze crianças, do sexo masculino e feminino, da primeira série do ensino fundamental público e que não apresentavam o repertório de ler e o de identificar números foram os participantes. Suas idades variavam entre 6 e 8 anos. Os comportamentos foram ensinados por meio de um procedimento de discriminação condicional. Verificou-se a ocorrência da aprendizagem sem erro das relações ensinadas para todos os Ps, exceto para um (P10). Nas etapas de testes das relações BC/CB, os Ps estabeleceram as equivalências. No teste das relações C'D, os Ps leram as novas expressões, agora compostas por palavras e números, além de outras expressões de generalização. Os dados são discutidos, mostrando que o ler e escrever palavras e identificar números são classes de estímulos equivalentes e que o ensino delas facilitou e promoveu a leitura com compreensão, tornando-se possível a extensão do procedimento para uma situação aplicada.

The Conjunction Fallacy: A Derived Stimulus Relations Conceptualization and Demonstration Experiment

The conjunction fallacy (CF) comes about when the occurrence of two events is rated as more likely than either in isolation. A typical participant in a CF study is presented with a description of a hypothetical individual (i.e., a compound sample stimulus) and then asked to make judgments as to the likelihood that that person engages in a particular vocation, avocation (i.e., single comparison stimuli), or both (i.e., a compound comparison stimulus). The CF is witnessed when the combination is judged as more likely than either the vocation or avocation alone. Commission of the CF is often attributed to participants’ judgment being guided by representativeness (i.e., the representativeness heuristic) rather than the laws of probability (Tversky & Kahneman, 1983). This paper provides a behavioral interpretation of CF responding based on derived/emergent stimulus relations and presents data from 27 undergraduates who participated in a study designed to test the plausibility of the interpretation. Using nonsense words and a many-to-one training structure, prerequisite baseline relationships for establishing two 6-member stimulus equivalence classes were trained. Next was an analogue CF test in which participants rated the likelihood that former sample stimuli (now presented as comparison stimuli, either alone or in sets of 2) were a correct answer given a compound sample stimulus composed of 3 former sample stimuli (all of which were from 1 class but had never been directly related during training). Following this test phase the emergence of equivalence classes was formally assessed and a standard CF scenario presented. The incidence of CF responding under the analogue procedure (60%) was similar to that reported in standard scenarios and commission of the CF was significantly related to whether equivalence classes formed. These data constitute a preliminary demonstration in support of the derived equivalence relations interpretation.

Preliminary Findings on the Effects of Self-Referring and Evaluative Stimuli on Stimulus Equivalence Class Formation

Thirty-two subjects completed 2 stimulus equivalence tasks using a matching-to-sample paradigm. One task involved direct reinforcement of conditional discriminations designed to produce derived relations between self-referring stimuli (e.g., me, myself, I) and positive evaluation words (e.g., whole, desirable, perfect). The other task was designed to produce derived relations between self-referring stimuli and negative evaluation wordls (e.g., unworthy, flawed, inadequate). Performance on each task was recorded via response latency and percent correct. Prior to completion of the equivalence tasks, subjects completed 2 self-report measures: the Outcome Ouestionnaire-45 (OQ-45) and the Rosenberg Self-Esteem Scale (RSE). Subjects were divided into groups based on their OQ-45 score (high or low distress) and RSE score (high or low self-esteem). Significant differences in percent correct were found between both the OQ-45 groups and the RSE groups. Subjects who reported high distress and a negative sense of self made significantly more errors on the tests for equivalence for the task that required matching self-referential stimuli with positive evaluation words.

刺激等価性手続きを用いた自閉性障害児における感情語理解の指導

The purpose of the present study was to examine the effectiveness of stimulus equivalence procedures for teaching 4 receptive emotional labels (happiness, anger, sadness, and surprise) to a 5-year 9-month-old girl with autistic disorder. Training programs were designed to teach the girl to match schematic expressive faces to printed emotional labels and to match cartoons depicting emotional situations to schematic faces. After both matching tasks met the learning criteria, she showed unreinforced conditional relations between the printed emotional labels and the emotional situation cartoons, indicating the emergence of stimulus equivalence classes. In addition, the results demonstrated expansion of the equivalence classes to photographs of expressive faces and sentences describing emotion-eliciting situations.

Increasing the Probability of Stimulus Equivalence with Adults with Mild Mental Retardation

In Experiment 1, 6 adults with mild mental retardation were taught 3 overlapping conditional discriminations in a linear series structure, establishing the possibility of the emergence of 2 stimulus equivalence classes of 4 stimuli per class. Training employed balanced trial types in which the discriminative stimuli were presented in fixed pairs across conditional discriminations (e.g., 81 and 82, C1 and C2). No participant.showed the emergence of equivalence classes in initial testing; 1 participant showed the establishment of classes with repeated testing, including tests for symmetry alone. In Experiment 2, 6 additional adults with mild mental retardation were similarly trained, with one methodological modification: Prior to testing, each comparison stimulus (e.g., 81) was presented in some trials with every stimulus from the opposing class (i.e., A2, 82, C2, and D2). With this modification, 4 of 6 participants showed the establishment of equivalence classes during initial testing. The results support hypotheses about the essential role of simple discrimination acquisition in equivalence class establishment.

General Symbol Machines: The First Stage in the Evolution of Symbolic Communication

Humans uniquely form stimulus equivalence (SE) classes of abstract and unrelated stimuli, i.e. if taught to match A with B and B with C, they will spontaneously match B with A, and C with B, (the relation of symmetry), and A with C (transitivity). Other species do not do this. The SE ability is possibly the consequence of a specific selection event in the Homo lineage. SE is of interest because it appears to demonstrate a facility that is core to symbolic behavior. Linguistic symbols, for example, are arbitrarily and symmetrically related to their referent such that the term banana has no resemblance to bananas but when processed can be used to discriminate bananas. Equally when bananas are perceived the term banana is readily produced. This relation is arguably the defining mark of symbolic representation. In this paper I shall detail the SE phenomenon and argue that it is evidence for a cognitive device that I term a General Symbol Machine (GSM). The GSM not only sets the background condition for subsequent linguistic evolution but also for other symbolic behaviors such as mathematical reasoning. In so doing the GSM is not particularly domain-specific. The apparent domain-specificity of, for example, natural language is a consequence of other computational developments. This introduces complexity to evolutionary arguments about cognitive architecture.

Efeito de instruções sobre a demonstração de equivalência entre posições

A maioria dos trabalhos sobre equivalência com participantes humanos resultou na formação de classes de equivalência independentemente das características dos estímulos empregados. Entretanto, uma série de estudos recentes utilizando a posição como dimensão relevante de estímulo mostrou resultados negativos, em sua maioria. O presente estudo pretendeu verificar se instruções que tornassem mais clara a tarefa dos participantes resultaria em melhor desempenho na formação de três classes de equivalência formadas pela posição relativa de nove quadrados compondo uma matriz três por três. Dez estudantes universitários que participaram do experimento receberam instruções mínimas. Onze outros receberam instruções adicionais instando-os a levar em conta nas próximas tentativas (tentativas de teste) o que aprenderam no decorrer do experimento (tentativas de linha de base). Dez participantes que receberam instruções adicionais e cinco que receberam instruções mínimas formaram as três classes equivalentes de posição. Deste modo parece evidente que as instruções adicionais facilitaram a formação de equivalência. Entretanto, o presente trabalho também difere dos anteriores em mais dois aspectos: 1) na utilização de uma cor diferente para cada classe, e 2) na permissão de um maior número de testes antes de concluir-se pela não formação de equivalência, favorecendo deste modo, mais extinção de respostas incompatíveis com as contingências programadas.

CONTEXTUAL CONTROL OF EQUIVALENCE‐BASED TRANSFORMATION OF FUNCTIONS

The transformation of functions refers to the untrained acquisition of stimulus functions among members of stimulus equivalence classes or relational frames. Although it is widely assumed that contextual control over the transformation of fuctions must exist, this has not yet been conclusively demonstrated in laboratory studies. Four experiments are reported in which (a) stimulus equivalence classes were established, (b) a conditional stimulus function was trained for one member of each of the classes, and (c) multiple-exemplar procedures were used to train and test for contextual control over the transformation of the stimulus function within the classes and to assess whether it generalized to new equivalence classes. Although a significant amount of training was required, the procedures ultimately resulted in the contextual control of function transformation for 9 of 10 participants and generalized contextual control for 4 of 5 participants.

Transfer and Stimulus Equivalence Classes Derived From Simultaneously Presented S+ and S- Stimuli

This study examined the effect of spatial contiguity on derived relational responding and transfer in populations with different mental ages: normal adults (Experiment 1), normal adolescents (Experiment 2), normal primary students (Experiment 3), adolescents with learning disabilities and a normal 7-year-old child (Experiments 4 and 5), and pre-school children (Experiment 6). The basic training and test sequence was the same in all experiments. After being trained on four simultaneous discrimination tasks with A and B stimuli (A1+/B1-, A2+/B2-, B1+/C1-, B2+/C2-) the subjects received match-to-sample probes measuring conditional relations between all directly and indirectly paired stimuli. Then, the subjects received transfer training (A1-clap, A2-wave), followed by transfer tests. Nineteen of the 21 subjects learned the training tasks. All these 19 subjects showed stimulus equivalence and transfer (A1-B1-C1-clap; A2-B2-C2-wave). These findings show that spatial contiguity, even among discriminative stimuli with incongruous functions, is a powerful procedure for establishing equivalence classes and transfer.

Emergence of Conditional Stimulus Relations and Transfer of Respondent Eliciting Functions Among Compound Stimuli

Previous research has demonstrated that conditioned elicitation functions can transfer via stimulus equivalence classes. However, thus far investigations in this area have been limited to stimulus equivalence classes involving single element stimuli. This study attempted to demonstrate the transfer of eliciting functions via emergent relations involving compound stimuli. Eight college students participated in this study. Six of these participated in all experimental procedures, while the remaining two served as controls and did not receive some phases of the experiment. The experimental participants were first taught nine conditional relations of compound stimuli and unitary stimuli (AC-B & BC-A) using match-to-sample training. They were then tested for the emergence of untrained relations involving different combinations of the previously learne9 compound-single element relations and compound-compound relations (AC-AC or AB-AB or BC-BC). A classical conditioning procedure was then performed in which one compound stimulus from one class was paired with mild electric shock (1.0-2.0 mA) while two other compounds from two different classes were presented in the absence of shock. Participants were then presented with other compounds from the appropriate classes to assess whether the eliciting function had transferred to stimuli which were members of the same class as the originally conditioned stimulus. The control participants received the same procedures except for the initial conditional discrimination training of the compound-single relations and the testing for the emergence of compound-single relations. Four of thoe six experimental participants demonstrated transfer of the eliciting function. An analysis of the performance of both of the individuals who failed to demonstrate the transfer revealed that they may have failed to ° maintain the classes throughout the experiment. One participant discontinued the experiment before further procedures

Transfer of skin conductance responses through stimulus equivalence classes

This study investigated the transfer of classically conditioned skin conductance responses through stimulus equivalence classes. Fourteen subjects were taught 4 stimulus relations, A1-->B1, A1-->C1, A2-->B2, and A2-->C2 through matching-to-sample training. In subsequent matching-to-sample tests, 13 subjects demonstrated the formation of two stimulus equivalence classes, "A1, B1, and C1" and "A2, B2, and C2." They then received differential conditioning, in which Stimulus B1 was followed by electric shocks, while B2 was not followed by the shocks. Subsequent transfer tests revealed that skin conductance responses for Stimulus C1 were greater than those for C2, suggesting the transfer of conditioned responses through the stimulus equivalence classes.

Generalization of Supermarket Shopping Skills for Individuals with Mild Intellectual Disabilities Using Stimulus Equivalence Training

We developed an intervention to promote generalization in an applied community setting. The intervention was derived primarily from experimental research examining stimulus equivalence classes and natural categories. Six young adults with intellectual disabilities were taught using (a) stimulus equivalence training, (b) multiple exemplar training, or (c) single instance training to complete a supermarket shopping task analysis. Results indicated that stimulus equivalence and multiple exemplar training were equally effective in promoting generalization with single instance training being the least effective.

Rational-emotive behavior therapy and the formation of stimulus equivalence classes.

Stimulus equivalence is a behavioral approach to analyzing the "meaning" of stimulus sets and has an implication for clinical psychology. The formation of three-member (A --> B --> C) stimulus equivalence classes was used to investigate the effects of three different sets of sample and comparison stimuli on emergent behavior. The three stimulus sets were composed of Rational-Emotive Behavior Therapy (REBT)-related words, non-REBT emotionally charged words, and a third category of neutral words composed of flower labels. Sixty-two women and men participated in a modified matching-to-sample experiment. Using a mixed cross-over design, and controlling for serial order effects, participants received conditional training and emergent relationship training in the three stimulus set conditions. Results revealed a significant interaction between the formation of stimulus equivalence classes and stimulus meaning, indicating consistently biased responding in favor of reaching criterion responding more slowly for REBT-related and non-REBT emotionally charged words. Results were examined in the context of an analysis of the importance of stimulus meaning on behavior and the relation of stimulus meaning to behavioral and cognitive theories, with special appraisal given to the influence of fear-related discriminative stimuli on behavior.

Rational‐emotive behavior therapy and the formation of stimulus equivalence classes

Rational‐emotive behavior therapy and the formation of stimulus equivalence classes

Untrained Temporal Differentiation and Equivalence Class Formation

The purposes of this study were to assess whether discriminative control over conjunc FR 5 t1 < IRT < t2 responding would transfer to members of stimulus equivalence classes; whether a formal test for equivalence would be necessary for such transfer to occur; and to compare the effectiveness of derived discriminative control through symmetry, versus equivalence relations. In Experiment 1, 2 out of 6 subjects demonstrated the reliable transfer of stimulus functions prior to the test for equivalence; in Experiment 2, none of 5 subjects demonstrated the reliable transfer of stimulus functions prior to the test for equivalence, but 2 did so following the test for equivalence; and in Experiment 3, all 4 subjects demonstrated the reliable transfer of stimulus functions prior to the test for equivalence. No differences were observed between the derived control exerted by stimuli that had entered into symmetry relations with training stimuli, versus those that had entered into equivalence relations with training stimuli. It was concluded that behavior can appear to be temporally differentiated in the absence of direct conditioning.