Harry A. Mackay

Stimulus Equivalence, Generalization, and Contextual Stimulus Control in Verbal Classes

Stimulus generalization and contextual control affect the development of equivalence classes. Experiment 1 demonstrated primary stimulus generalization from the members of trained equivalence classes. Adults were taught to match six spoken Icelandic nouns and corresponding printed words and pictures to one another in computerized three-choice matching-to-sample tasks. Tests confirmed that six equivalence classes had formed. Without further training, plural forms of the stimuli were presented in tests for all matching performances. All participants demonstrated virtually errorless performances. In Experiment 2, classifications of the nouns used in Experiment 1 were brought under contextual control. Three nouns were feminine and three were masculine. The match-to-sample training taught participants to select a comparison of the same number as the sample (i.e., singular or plural) in the presence of contextual stimulus A regardless of noun gender. Concurrently, in the presence of contextual stimulus B, participants were taught to select a comparison of the same gender as the sample (i.e., feminine or masculine), regardless of number. Generalization was assessed using a card-sorting test. All participants eventually sorted the cards correctly into gender and number stimulus classes. When printed words used in training were replaced by their picture equivalents, participants demonstrated almost errorless performances.

Guiding visual attention during acquisition of matching-to-sample.

Matching-to-sample skills are involved in language acquisition and the development of basic reading and counting abilities. The rapid, even errorless, induction of matching performances in young children and individuals with mental retardation was demonstrated here through the structuring of a visual array so as to promote detection of the relevant stimulus. Implications for theory and application are discussed.

Categories of Relations Between Stimuli: Foundations for Transitive Inference and Other Emergent Behavior

Recently, Vigo and Allen (2009) proposed a view of transitive inference as categorization that depends only on discriminative performances, similarity judgments, and the formation of categories of which non-human animals and non-verbal humans are capable. Rather than involving language-based statements of premises, a network of simple discriminations provides the prerequisites for the emergence of new discriminations involving the transitive relations among stimuli. This view is illustrated briefly here and considered in the broader contexts of two experimental situations of interest to behavior analysts: repeated discrimination reversal training and symmetry in pigeons.

Rapid generation of balanced trial distributions for discrimination learning procedures: a technical note.

We describe novel computer algorithms for rapid, sometimes virtually instantaneous generation of trial sequences needed to instrument many behavioral research procedures. Implemented on typical desktop or laptop computers, the algorithms impose constraints to forestall development of undesired stimulus control by position, recent trial outcomes, and other variables that could impede simple and conditional discrimination learning. They yield trial-by-trial lists of sequences that can serve (1) as inputs to procedure control software or (2) in generating templates for constructing sessions for implementation by hand or machine.

Developing Syntactic Repertoires: Syntheses of Stimulus Classes, Sequences, and Contextual Control

A variety of complex repertoires, (e.g., language, numeric and musical skills) possess orderly syntactic properties, are generalized and productive, and vary with current context. Here, such repertoires and other examples that have been developed experimentally are discussed in terms of a behavior analysis that involves syntheses of serial learning, class formation, and contextual stimulus control.

Measuring the “transfer of meaning” through members of equivalence classes merged via a class-specific reinforcement procedure

Seven participants received conditional discrimination training that established the 12 conditional relations A1B1, A2B2, A3B3, A1C1, A2C2, A3C3, D1E1, D2E2, D3E3, D1F1, D2F2, and D3F3. The A stimuli were pictures of faces portraying emotional expressions; the others were arbitrary forms. Correct responses resulted in presentations of class-specific reinforcers, Sr1, Sr2, and Sr3. After training, tests confirmed the formation of ABC and DEF equivalence classes. Further tests then documented the merger of the classes and the emergence of SrB, SrC, SrE, and SrF relations, showing that the class-specific reinforcers were equivalence class members. Finally, participants did Semantic Differential ratings that tested whether the emotional valence of the A stimuli transferred to the arbitrary forms, B and E. The results show that participants’ evaluations of the B and E stimuli were similar to evaluations of the A stimuli made by participants of a control group. This finding is considered as a demonstration that class-specific outcomes can mediate class merger phenomena and the transfer of functions through members of merged classes.

Teaching stimulus–stimulus relations to minimally verbal individuals: reflections on technology and future directions

ABSTRACT 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 contents. 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 who exhibit unusual difficulties in learning. Given this background, we suggest a way forward to better understand and perhaps resolve these learning challenges.

ESTABELECIMENTO E REORGANIZAÇÃO DE RELAÇÕES ARBITRÁRIAS DERIVADAS APÓS O TREINO EM MATCHING-TO-SAMPLE DE IDENTIDADE COM CONSEQUÊNCIAS ESPECÍFICAS

No Experimento 1, seis participantes foram treinados em um procedimento MTS de identidade (IDMTS) para estabelecer relacoes estimulo-estimulo A1A1, A2A2, A3A3; B1B1, B2B2, B3B3; e C1C1, C2C2, C3C3. Respostas corretas resultavam na apresentacao de consequencias especificas, Sr1, Sr2 e Sr3. Uma resposta de consumacao as consequencias especificas foi requerida para que os participantes pudessem coletar os pontos nas tentativas de treino. O procedimento MTS arbitrario foi utilizado para documentar a formacao de tres classes de equivalencia A1B1C1Sr1, A2B2C2Sr2 e A3B3C3Sr3. Em uma fase subsequente, o IDMTS com consequencias especificas foi empregado para treinar as relacoes D1D1, D2D2 e D3D3. Os estimulos D eram fotografias de faces humanas expressando alegria (D1), tristeza (D2) e neutralidade (D3). Por ultimo, avaliacoes por meio do diferencial semântico atestaram a ocorrencia da transferencia das funcoes (i.e., “significados”) dos estimulos D para os estimulos C e para Sr1 e Sr3. Estes resultados sugeriram que as classes ABCSr se expandiram para incluir os estimulos significativos D (i.e., A1B1C1D1Sr1, A2B2C2D2Sr2 e A3B3C3D3Sr3). No Experimento 2 verificou-se que, para cinco participantes, o procedimento de reversao das consequencias especificas Sr1 e Sr2 em relacao aos estimulos C1, C2 e D1 e D2 deu origem a duas classes de equivalencia reorganizadas (A1B1C2D2Sr2 e A2B2C1D1Sr1). Paralelamente, os dados do diferencial semântico documentaram a reversao dos significados atribuidos previamente aos estimulos D1 e D2. Estes achados sugerem que o procedimento de reversao reorganizou as classes de estimulos bem como seus significados. Porem, resultados analogos nao foram reportados para as consequencias especificas. Palavras-chave : Matching-to-sample de identidade, consequencias especificas, classes de equivalencia, reorganizacao de classes de equivalencia, transferencia de funcao, universitarios

From semantic to syntactic repertoires: the significance of three-term contingencies

ABSTRACT Three-term contingencies relate discriminative stimuli, responses, and reinforcers. Their fundamental importance is recognized widely by behavioral scientists. Sidman (1994) expresses the view that “the three-term contingency is the basic analytic unit of cognition,” a view based on experimental analyses of the contingencies that establish the prerequisites for complex relational performances that emerge without direct training. This now extensive area of research has examined primarily the development of semantic repertoires (e.g., the substitutability, more formally equivalence, of stimuli). The focus here is to relate research on sequence production and discrimination (i.e., syntactic repertoires) to Sidman’s view of the importance of three-term behavioral units generated by reinforcement contingencies. Consideration of syntactic repertoires will highlight and extend the range of phenomena to which that view may apply.