EQUIVALÊNCIA DE ESTÍMULOS EM PARTICIPANTES COM SÍNDROME DE DOWN: EFEITOS DA UTILIZAÇÃO DE PALAVRAS COM DIFERENÇAS MÚLTIPLAS OU CRÍTICAS E ANÁLISE DE CONTROLE RESTRITO DE ESTÍMULOS

The present study attempted to investigate stimulus equivalence formation by participants with Down’s syndrome. Participants learned auditory-visual conditional discriminations with pseudo-words and was manipulated the stimulus similarity in two experimental conditions. The stimuli had multiple differences between them in the first condition, and had critical differences between them in the second condition. Four individuals with Down’ssyndrome participated. Relations between dictated words and pictures and between dictated and printed words were trained through matching to sample procedures. Two participants also learned responses of constructing the words by the ordinal selection of their elements. Performances tested were naming of printed words and pictures, and matching printed words to pictures and pictures to printed words. Results suggested that three of the four participants formed equivalence classes in both experimental conditions, whereas the other participant showed signs of class formation only in the first experimental condition. Two participants had more difficulties with training and testing in the second condition. The difficulties were attributed to restricted stimulus control.Key words: stimulus equivalence, reading, stimulus similarity, stimulus control, Down’s syndromeO presente trabalho teve o propósito de investigar a formação de equivalência de estímulos com indivíduos portadores de Síndrome de Down. Foram ensinadas discriminações condicionais auditivo-visuais para tais participantes, utilizando pseudo-palavras e manipulando distintamente o número de elementos idênticos (letras) presentes nas palavras em duas condições experimentais. Os estímulos utilizados foram palavras dissílabas do tipo consoante mais vogal. Na primeira das condições experimentais, as palavras apresentavam diferenças múltiplas (uma ou duas letras em comum) e na segunda, diferenças críticas entre si (palavras com três ou quatro letras em comum). Os participantes foram quatro indivíduos com Síndrome de Down. Foram treinadas, por meio de procedimentos de emparelhamento com o modelo, as relações entre palavras ditadas e figuras, e entre palavras ditadas e impressas. Com dois participantes, treinou-se também as respostas de construção por meio da seleção ordenada de cada elemento do estímulo impresso. Foram testadas as nomeações de palavras impressas e figuras e os emparelhamentos entre palavra impressa-figura e figura-palavra impressa. Os resultados sugerem que três dos quatro participantes apresentaram a formação de classes de equivalência nas duas condições experimentais. O outro participante mostrou indícios de formação de classes apenas na primeira condição experimental. Dois participantes apresentaram maiores dificuldades nos treinos e testes da segunda condição. As dificuldades encontradas por eles podem ser atribuídas a controle restrito de estímulos. Palavras-chave: equivalência de estímulos, leitura, similaridade entre os estímulos, controle de estímulos, Síndrome de Dow

Eye fixations to figures in a four-choice situation with luminance balanced areas: Evaluating practice effects

Contingency analyses of eye movements may reveal variables that are relevant to the stimulus control of observing behavior. The present research tracked the eye movements of four adults exposed to a simultaneous discrimination among four stimuli, two two-dimensional (square and circle) and two three-dimensional (cube and cylinder) mono-chromatic figures with approximately equal luminance. On each discrimination trial, the stimuli were displayed in the four corners of a video monitor and participants chose among them by pressing corresponding keys. For two participants, choosing either cube or square (S+) was followed by the word “correct” and a 3-second inter-trial interval. Alternatively, choosing either cylinder or circle (S-) was followed by "incorrect" and a 30-second inter-trial interval. For the other two participants, contingencies were reversed. The position of the stimuli on the screen varied randomly across trials. The procedure continued for 80 trials. During these trials, discriminated choices were established. Despite the presence of both a two- and a three-dimensional S+ on each trial, responses to the three-dimensional S+ tended to prevail. Although general eye fixations tended to decrease as discrimination was established, subjects tended to observe S+ for longer durations than S-. Characteristics of the stimuli may interact with the contingencies of reinforcement in the stimulus control of observing behavior

AN OVERVIEW OF NATIONAL STUDIES ON THE ACQUISITION OF NAMING IN PROCEDURES WITH STIMULUS EQUIVALENCE AND COCHLEAR IMPLANT USERS

O presente artigo teve por objetivo descrever e analisar, criticamente, o conjunto de experimentos conduzidos por pesquisadores brasileiros a respeito de equivalência de estímulos, nomeação e implante coclear, publicados entre 2008 e 2013. Para tanto, realizou-se um levantamento bibliográfico, em periódicos da área da análise do comportamento e em bancos de teses e dissertações, selecionando-se trabalhos sobre equivalência de estímulos, implante coclear e nomeação. Foram analisados 11 estudos. Após a análise dos estudos, tornou-se possível sugerir que os procedimentos de ensino, comumente aplicados em participantes com implante coclear, foram mais eficientes para estabelecer comportamentos de seleção de figuras e de palavras impressas – ambos considerados repertório receptivo –, do que para estabelecer comportamentos de nomeação de figuras e de palavras impressas, que são comportamentos associados à leitura expressiva. Nesta perspectiva, percebe-se como são necessários avanços tecnológicos nos procedimentos de ensino que se propõem a instalar e manter comportamentos associados à leitura expressiva, a ponto de serem tão eficazes quanto os procedimentos de ensino que instalam e mantêm o repertório receptivo. Palavras chave: equivalência de estímulos, implante coclear, nomeação.This paper aims to describe and critically analyze the set of experiments conducted by Brazilian researchers on stimulus equivalence, naming (expressive repertoire) and cochlear implants, which were published between 2008 and 2013. To this end, a literature review in journals of Behavior Analysis, and banks of theses and dissertations, selecting work on stimulus equivalence, cochlear implants and naming, was conducted. 11 studies were analyzed. After analyzing the studies, it was possible to suggest that the teaching procedures, more often used with participants with cochlear implants, have been more efficient to establish picture and printed words selection behaviors - both considered receptive repertoire - than to establish naming pictures and printed words behaviors, which are behaviors associated with expressive reading. In this perspective, it became clear how necessary technological advances in teaching procedures that propose to install and maintain behaviors associated with expressive reading, as effective as teaching procedures that install and maintain behaviors associated with receptive reading. Keywords: stimulus equivalence, cochlear implant, naming.

Emergent relations in pigeons following training with temporal samples

In two experiments, we investigated emergent conditional relations in pigeons using a symbolic matching-to-sample task with temporal stimuli as the samples and hues as the comparisons. Both experiments comprised three phases. In Phase I, pigeons learned to choose a red keylight (R) but not a green keylight (G) after a 1-s signal. They also learned to choose G but not R after a 4-s signal. In Phase II, correct responding consisted of choosing a blue keylight (B) after a 4-s signal and a yellow keylight (Y) after a 16-s signal. Comparisons G and B were both related to the same 4-s sample, whereas comparisons R and Y had no common sample. In Phase III, R and G were presented as samples, and B and Y were presented as the comparisons. The choice of B was correct following G, and the choice of Y was correct following R. If a relation between comparisons that shared a common sample were to emerge, then responding to B given G would be more likely than responding to Y given R. The results were generally consistent with this prediction, suggesting, for the first time in pigeons, the emergence of novel relations that involve temporal stimuli as nodal samples.This research was supported by doctoral grants to E.M.H. (FAPESP 60678-4/05 and CAPES 0103/08 0) and S.M.V. (CNPq 142544/2005-1 and CAPES 4457 07 2). G.Y.T. and D.G.d.S. were supported by a research productivity fellowship from The National Council for Scientific and Technological Development (CNPq, Brazil). A.D.M. was funded by the Portuguese Foundation for Science and Technology (FCT). All of the Brazilian authors are currently affiliated with the National Institute of Science and Technology on Behavior, Cognition and Teaching, supported by FAPESP (Grant No. 08/57705-8) and CNPq (Grant No. 573972/2008-7). The data were collected in the Animal Learning and Behavior Laboratory, University of Minho, Portugal, and were presented at the 36th Annual Meeting of the Brazilian Society of Psychology (SBP), Goiania, Brazil, in October 2009. E.M.H. is currently a college professor at the Universidade Federal de Minas Gerais.info:eu-repo/semantics/publishedVersio

Emergent Conditional Relations in a Go/No-Go Procedure: Figure–ground and Stimulus-Position Compound Relations

Past research has demonstrated emergent conditional relations using a go/no-go procedure with pairs of figures displayed side-by-side on a computer screen. The present study sought to extend applications of this procedure. In Experiment 1, we evaluated whether emergent conditional relations could be demonstrated when two-component stimuli were displayed in figure–ground relationships—abstract figures displayed on backgrounds of different colors. Five normally capable adults participated. During training, each two-component stimulus was presented successively. Responses emitted in the presence of some stimulus pairs (A1B1, A2B2, A3B3, B1C1, B2C2 and B3C3) were reinforced, whereas responses emitted in the presence of other pairs (A1B2, A1B3, A2B1, A2B3, A3B1, A3B2, B1C2, B1C3, B2C1, B2C3, B3C1 and B3C2) were not. During tests, new configurations (AC and CA) were presented, thus emulating structurally the matching-to-sample tests employed in typical equivalence studies. All participants showed emergent relations consistent with stimulus equivalence during testing. In Experiment 2, we systematically replicated the procedures with stimulus compounds consisting of four figures (A1, A2, C1 and C2) and two locations (left – B1 and right – B2). All 6 normally capable adults exhibited emergent stimulus–stimulus relations. Together, these experiments show that the go/no-go procedure is a potentially useful alternative for studying emergent conditional relations when matching-to-sample is procedurally cumbersome or impossible to use

Relational Learning in Children with Deafness and Cochlear Implants

This four-experiment series sought to evaluate the potential of children with neurosensory deafness and cochlear implants to exhibit auditory–visual and visual–visual stimulus equivalence relations within a matching-to-sample format. Twelve children who became deaf prior to acquiring language (prelingual) and four who became deaf afterwards (postlingual) were studied. All children learned auditory–visual conditional discriminations and nearly all showed emergent equivalence relations. Naming tests, conducted with a subset of the children, showed no consistent relationship to the equivalence-test outcomes. This study makes several contributions to the literature on stimulus equivalence. First, it demonstrates that both pre- and postlingually deaf children can acquire auditory–visual equivalence relations after cochlear implantation, thus demonstrating symbolic functioning. Second, it directs attention to a population that may be especially interesting for researchers seeking to analyze the relationship between speaker and listener repertoires. Third, it demonstrates the feasibility of conducting experimental studies of stimulus control processes within the limitations of a hospital, which these children must visit routinely for the maintenance of their cochlear implants

Associative Symmetry by Pigeons after Few-Exemplar Training

The present experiment investigated whether pigeons can show associative symmetry on a two-alternative matching-to-sample procedure. The procedure consisted of a within-subject sequence of training and testing with reinforcement, and it provided (a) exemplars of symmetrical responding, and (b) all prerequisite discriminations among test samples and comparisons. After pigeons had learned two arbitrary-matching tasks (A–B and C–D), they were given a reinforced symmetry test for half of the baseline relations (B1–A1 and D1–C1). To control for the effects of reinforcement during testing, two novel, nonsymmetrical responses were concurrently reinforced using the other baseline stimuli (D2–A2 and B2–C2). Pigeons matched at chance on both types of relations, thus indicating no evidence for symmetry. These symmetrical and nonsymmetrical relations were then directly trained in order to provide exemplars of symmetry and all prerequisite discriminations for a second test. The symmetrical test relations were now B2–A2 and D2–C2 and the nonsymmetrical relations were D1–A1 and B1–C1. On this test, 1 pigeon showed clear evidence of symmetry, 2 pigeons showed weak evidence, and 1 pigeon showed no evidence. The previous training of all prerequisite discriminations among stimuli, and the within-subject control for testing with reinforcement seem to have set favorable conditions for the emergence of symmetry in nonhumans. However, the variability across subjects shows that methodological variables still remain to be controlled

Emergent relations in pigeons following training with temporal samples

In two experiments, we investigated emergent conditional relations in pigeons using a symbolic matching-to-sample task with temporal stimuli as the samples and hues as the comparisons. Both experiments comprised three phases. In Phase I, pigeons learned to choose a red keylight (R) but not a green keylight (G) after a 1-s signal. They also learned to choose G but not R after a 4-s signal. In Phase II, correct responding consisted of choosing a blue keylight (B) after a 4-s signal and a yellow keylight (Y) after a 16-s signal. Comparisons G and B were both related to the same 4-s sample, whereas comparisons R and Y had no common sample. In Phase III, R and G were presented as samples, and B and Y were presented as the comparisons. The choice of B was correct following G, and the choice of Y was correct following R. If a relation between comparisons that shared a common sample were to emerge, then responding to B given G would be more likely than responding to Y given R. The results were generally consistent with this prediction, suggesting, for the first time in pigeons, the emergence of novel relations that involve temporal stimuli as nodal samples.This research was supported by doctoral grants to E.M.H. (FAPESP 60678-4/05 and CAPES 0103/08 0) and S.M.V. (CNPq 142544/2005-1 and CAPES 4457 07 2). G.Y.T. and D.G.d.S. were supported by a research productivity fellowship from The National Council for Scientific and Technological Development (CNPq, Brazil). A.D.M. was funded by the Portuguese Foundation for Science and Technology (FCT). All of the Brazilian authors are currently affiliated with the National Institute of Science and Technology on Behavior, Cognition and Teaching, supported by FAPESP (Grant No. 08/57705-8) and CNPq (Grant No. 573972/2008-7). The data were collected in the Animal Learning and Behavior Laboratory, University of Minho, Portugal, and were presented at the 36th Annual Meeting of the Brazilian Society of Psychology (SBP), Goiania, Brazil, in October 2009. E.M.H. is currently a college professor at the Universidade Federal de Minas Gerais.info:eu-repo/semantics/publishedVersio