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.

Do common elements predict class merger: A test of Sidman's theory of equivalence.

The study presented here investigated the effect of common and uncommon elements on class merger as predicted by Sidman in his reconceptualization of stimulus equivalence suggesting that common elements among contingencies can facilitate emergent performances (1994, 1997, 2000). Eight adult participants were exposed to a procedure that arranged for stimulus-reinforcer correlations in Phase 1 and response-reinforcer correlations in Phase 2 of a 3-phase study. In the common element group, the visual images serving as reinforcers were the same in Phase 1 and Phase 2. In the uncommon elements group, the images serving as reinforcers were different in Phases 1 and 2. In Phase 3, participants were given an opportunity to respond but no feedback was programmed. The results showed that participants' responding was well differentiated in the common element group and undifferentiated in the uncommon elements group. These results are predicted by Sidman's revised formulation of the provenance and scope of equivalence relations. Specifically, these data support Sidman's (1994, 1997, 2000) suggestion that elements of a contingency enter into an equivalence class and common elements among contingencies are sufficient to produce class mergers. The findings highlight an emergent simple discrimination and raise some interesting considerations about the definition of equivalence under the new formulation.

Avaliação de controle restrito de estímulos em tarefas de discriminação simples em pré-escolares / Assessing restricted stimulus control in simple discrimination tasks in preschool children

O controle de estímulos exercido por algumas propriedades ou aspectos de um estímulo antecedente contingente ao reforço é definido como controle restrito de estímulos. O objetivo do estudo foi investigar o controle discriminativo por elementos de estímulos visuais compostos em tarefas de discriminação simples. Participaram catorze pré-escolares (seis com autismo e oito com desenvolvimento típico) entre quatro e seis anos de idade. O procedimento envolveu o ensino de discriminação simples entre um par de estímulos visuais compostos por dois elementos. Em seguida, foram realizadas sondas para avaliar o controle discriminativo por cada elemento do estímulo composto (S+ e S-). Todas as crianças responderam aos dois elementos do S+ e não responderam, ou responderam com baixa frequência, aos elementos do S- dos três pares de estímulos treinados e avaliados separadamente. Os resultados demonstraram que os pré-escolares com autismo e desenvolvimento típico responderam sob controle dos elementos dos estímulos S+. O investimento no estudo do controle restrito de estímulos pode contribuir na compreensão desse fenômeno como um processo comportamental básico.

The control of stimuli exercised by some of the properties or aspects of an antecedent stimulus contingent upon reinforcement is defined as restricted control of stimuli. The aim of this study was to investigate discriminative control by the elements of a composite visual stimuli in simple discrimination tasks. Fourteen preschool children (six with autism and eight typical development) between four and six years old participated. The procedure involved the simple discrimination learning between a pair of visual stimuli composed of two elements. Then, probes were carried out to evaluate the discriminatory control for each element of stimulus compound (S+ and S-). All children responded to both elements of S+ and did not respond or responded with low frequency to the elements of S- for the three pairs of stimuli trained and evaluated separately. The results showed that preschool children with autism and typical development responded under control of all the elements S+ stimuli. The investment in the study of the restricted control of stimuli can contribute to the understanding of this phenomenon as a basic behavioral process.

Simple discrimination in stingless bees (Melipona quadrifasciata): Probing for select- and reject-stimulus control.

Simple and conditional discrimination training may produce various types of controlling relations. Responses may be controlled primarily by the positive stimulus (select-control relation) or by the negative stimulus (reject-control relation; the subject excludes the negative stimulus and chooses the positive). Bees learn to respond in simple and conditional discriminations. However, no study has searched for reject-control responding in Melipona bees. We trained Melipona quadrifasciata on a simple discrimination task (S+ vs. S-; e.g., blue vs. yellow) and then probed for stimulus control with two types of probe trials, S+ versus a new stimulus (Select-control probes) and S- versus a new stimulus (Reject-control probes). For Group Different, a new-stimulus color (e.g., white) was used in one type of probe and another color (e.g., black) was used in the other type. For Group Same, a single new-stimulus color was used in both types of probes. On Select probes, the bees always preferred S+ to the new stimulus. On Reject probes, results were mixed. Depending on the colors used in training and probing, bees responded to both stimuli, and even preferred the S-. The data suggest no control by the negative function of the S- and support the select-stimulus control hypothesis of responding.

The fate of redundant cues in human predictive learning: The outcome ratio effect.

In four experiments, participants were shown a sequence of pairs of pictures of food and asked to predict whether each pair signalled an allergic reaction in a hypothetical patient. The pairs of pictures were used to present two simple discriminations that differed in their outcome ratio. A rich discrimination, 3AX+ BX-, involved three trials in which the compound of two foods, AX, was followed by a reaction, for every trial in which the compound BX was not followed by the outcome. A lean discrimination, CY+ 3DY- was based on the opposite outcome ratio. Upon the completion of this training, participants were asked to rate how likely an individual food would be followed by the allergic reaction. In each experiment, the rating for X was stronger than for Y. This outcome ratio effect poses a challenge for theories of learning that assume changes in associative strength are governed by a common error term, based on the significance of all the cues present on a trial. Instead, the results are consistent with the assumption that changes in associative strength are governed by an individual error term, based on the significance of a single cue.

Canine human-scent-matching: The limitations of systematic pseudo matching-to-sample procedures.

Here transfer performance is contrasted with baseline training performance to determine whether a relational solution strategy is learned from the systematic pseudo matching-to-sample procedures commonly used to train human-scent-matching dogs. Evidence indicates that due to the lack of constraints to control against simple discrimination solutions, dogs trained with systematic pseudo matching-to-sample arrangements do not learn to use the scent sample as a signaling cue and do not learn about the matching relationship between the scent sample and matching comparison. Moreover, during pseudo matching-to-sample training, dogs may learn to ignore both the scent sample and the discriminative dimension of human scent, such as genetic information. Thus, during subsequent random control matching-to-sample (MTS) conditional discrimination training, learning about the matching relationship between the individual-unique information on the scent sample and matching comparison can be retarded. Failure to identify the solution strategy that human-scent-matching dogs must learn in order to perform accurately and reliably during operations and to distinguish between simple discrimination, random control MTS conditional discrimination, and systematic pseudo matching-to-sample has been a major drawback to the advancement of scent-matching dogs and is a contributing factor to the continued controversy surrounding their use and reliability.

Equivalence class formation via class-specific consequences in children diagnosed with autism spectrum disorder / Formação de classes de equivalência via consequências específicas das classes em crianças diagnosticadas com transtorno do espectro do autismo / Formación de clases equivalentes a través de consecuencias específicas de clase en niños diagnosticados con trastorno del espectro autista

Previous equivalence-class formation studies, with class-specific consequences, found inter-subject variability, probably due to loss of efficacy of the consequences as reinforcers. This study evaluated (a) the efficacy of introducing variations of events (within a category) as class-specific consequences and (b) the inclusion of these consequences into the equivalence classes. Two children diagnosed with Autism Spectrum Disorder (ASD), and with intellectual disabilities, were given identity matchingto-sample training (Set A - Sample A1, S+A1/S-A2 and Sample A2, S+A2/S-A1) and simple discrimination reversal training (Set B - S+B1/S-B2 and reversals). Two sets of assorted videos on the same theme plus two sets of assorted food items within the same category were used as class-specific consequences. The data show that the variety of elements was efficient to maintain reinforcement efficacy and encourage the use of similar procedures in the applied context. Both participants showed strong evidence of equivalence class formation, confirming the theoretical prediction regarding the inclusion of the class-specific consequences in the classes. The data confirm that equivalence relations can be found in three-term contingencies.

Estudos anteriores sobre a formação de classes de equivalência, com consequências específicas para as classes, apontaram variabilidade intersujeitos provavelmente devida a perda de eficácia das consequências como reforçadores. O presente estudo avaliou (a) a eficácia da introdução de variações de eventos (dentro de uma categoria) como consequências específicas das classes e (b) a inclusão de tais consequências nas classes. Duas crianças diagnosticadas com Transtorno do Espectro do Autismo (TEA), e com deficiência intelectual, foram submetidas a treino de emparelhamento ao modelo (Conjunto A - Modelo A1, S+A1/S-A2 e Modelo A2, S+A2/S-A1) e treino de reversões de discriminações simples (Conjunto B - S+B1/S-B2 e reversões). Dois conjuntos de vídeos variados de um mesmo tema e dois conjuntos de alimentos variados dentro de uma mesma categoria foram usados como consequências específicas. Os dados mostram que a variedade de elementos foi eficiente para manter a eficácia do reforçamento e encoraja o uso de procedimentos similares em contexto aplicado. Ambos os participantes mostraram forte evidência de formação de classes de equivalência, confirmando a predição teórica sobre a inclusão de consequências específicas nas classes. Os dados confirmam que relações de equivalência podem ser encontradas em contingências de três termos.

Estudios previos de formación de clases de equivalencia, con consecuencia específica de clase, encontraron variabilidad interindividual probablemente debido a la pérdida de eficacia de las consecuencias como reforzadores. Este estudio evaluó (a) la eficacia de la introducción de variaciones de eventos (dentro de una categoría) como consecuencias específicas de clase y (b) la inclusión de tales consecuencias en las clases de equivalencia. Dos niños diagnosticados con Trastorno del Espectro Autista y con discapacidad intelectual, recibieran entrenamiento de igualación de identidad a la muestra (Conjunto A - Muestra A1, S+A1/S-A1 y Muestra A2, S+A2/S-A1) y entrenamiento de inversión de la discriminación simple (Conjunto B - S+B1/S-B2 y inversiones). Se utilizaron dos conjuntos de vídeos diversos de un mismo tema, más dos conjuntos de alimentos diversos dentro de la misma categoría como consecuencias específicas de clase. Los datos muestran que la variedad de elementos fue eficiente para mantener la eficacia del refuerzo y fomentan el uso de procedimientos similares en contexto aplicado. Ambos los participantes mostraron una fuerte evidencia de la formación de clases de equivalencia, lo que confirma la predicción teórica sobre la inclusión de las consecuencias específicas de clase en las clases de equivalencia. Los datos confirman que las relaciones de equivalencia pueden ser encontradas en las contingencias de tres términos.

Classes de Equivalência: Efeitos do Elemento Redundante e da Ordem dos Testes / Equivalence Classes: Effects of the Redundant Element and the Order of Tests

RESUMO Avaliou-se o efeito da ordem dos testes na formação de classes de equivalência e no controle de estímulos após ensino de discriminação simples simultânea com um elemento redundante (mancha preta). Dezenove universitários realizaram treino de relações condicionais, além de testes de equivalência e de controle de estímulos com máscara. A ordem dos testes foi alterada em duas fases experimentais: (1) testes intercalados com treinos e (2) testes após os treinos. A mancha aparecia em um dos estímulos de treino. Desempenhos mais precisos ocorreram em testes conduzidos no final dos treinos. Escores altos foram relacionados com controle pelo S+ e pelo S- e os mais baixos com múltiplos controles, principalmente pela mancha. Sugere-se que a ordem dos testes interage com efeitos do elemento redundante.

ABSTRACT It was investigated the effect of the order of testing on equivalence class formation and stimulus control after teaching simple discriminations that included a redundant element (black spot). Nineteen college students were exposed to conditional relations training, as also testing of equivalence classes and stimulus control with mask. The order of testing varied in two experimental phases: (1) tests alternated with training, and (2) tests after training. A black spot was included in one of the compound stimuli. More accurate performances occurred when tests were conducted after training. Higher scores were related to control by S + and the S- and lower scores to multiple controls that included the black spot. These results suggest that the order of testing interact with the effects of the redundant element.

Reversal learning and experimenter-administered chronic intermittent ethanol exposure in male rats.

RATIONALE: Chronic alcohol exposure is associated with impaired decision making skills, cognitive deficits, and poor performance on tasks requiring behavioral flexibility. Although oral routes of alcohol administration are commonly used to examine effects of alcohol on various behaviors in rodents, only a few investigations have used intragastric exposures to evaluate ethanol's effects on behavioral flexibility in the adult rat. OBJECTIVES: The aim of the current series of experiments was to determine if behavioral flexibility impairments would be demonstrated across a variety of procedural factors, including route of administration [intraperitoneal injection (i.p.), intragastric gavage (i.g.)], ethanol dose (3-5 g/kg), number of daily exposures (once/day, twice/day), duration of exposure (2-6 weeks), or length of abstinence (5-7 days). METHODS: Adult male Sprague-Dawley rats were exposed to chronic intermittent ethanol (CIE) or vehicle and evaluated for behavioral intoxication, blood ethanol concentrations (BEC), and performance on a reversal learning odor discrimination task. RESULTS: While all rats displayed behavioral intoxication and elevated BECs, CIE i.p. rats had prolonged elevation in BECs and made the most errors during the reversal learning task. Unexpectedly, CIE i.g. exposures failed to produce deficits during reversal learning tasks regardless of ethanol dose, frequency/duration of exposure, or length of abstinence. CONCLUSIONS: Behavioral flexibility deficits resulting from CIE i.p. exposures may be due to the severity and chronicity of alcohol intoxication. Elucidating the impact of ethanol on behavioral flexibility is critical for developing a better understanding of the behavioral consequences of chronic alcohol exposure.

Ensino de linguagem receptiva para crianças com autismo: comparando dois procedimentos / La enseñanza del lenguaje receptivo para niños con autismo: comparación de dos procedimientos / Comparing two procedures for teaching receptive language to children with autism

Este trabalho comparou a eficiência de um treino de Discriminação Simples-Condicional (DSC), que empregou blocos de tentativas e três estímulos desde o seu início, com a do treino de Discriminação Condicional (DC), no ensino de linguagem receptiva para três crianças com autismo. Com cada criança foram treinadas nove relações palavra falada-figura em cada tipo de treino. O treino DSC consistiu na redução gradual de tentativas por bloco (de seis blocos de três tentativas, na Fase 1 para nove blocos de duas tentativas, na Fase 2), até sua randomização total, na Fase 3. O treino DC foi idêntico à Fase 3 de DSC, porém com outros estímulos. O treino DC se mostrou mais eficiente para o estabelecimento da linguagem receptiva, mas o treino DSC foi mais efetivo para a manutenção do repertório. Discutem-se as implicações desses resultados para a área aplicada e direções para novos estudos.

Este estudio comparó la eficiencia de un procedimiento de Discriminación Simple-Condicional (DSC) que empleó bloques de ensayos y tres estímulos desde su inicio, con la de uno de Discriminación Condicional (DC) en la enseñanza del lenguaje receptivo para tres niños con autismo. Cada niño fue entrenado en nueve relaciones palabra hablada-figura en cada tipo de procedimiento. El procedimiento DSC consistió en seis bloques de tres ensayos en la Fase 1, en nueve bloques de dos ensayos en la Fase 2, y en ensayos aleatorizados en la Fase 3. El procedimiento DC fue idéntico a la Fase 3 del DSC, pero con otros estímulos. El procedimiento DC fue más eficiente para el establecimiento de lenguaje receptivo, pero el DSC fue más eficaz para el mantenimiento del repertorio. Se discuten las implicaciones de estos resultados para el área aplicada y direcciones para futuras investigaciones.

This study compared the efficiency of a Simple-Conditional Discrimination (SCD) procedure that from the start used trial blocks and three stimuli, with another procedure of Conditional Discrimination (CD) in teaching receptive language to three autistic children. Each child was trained in nine spoken-word/figure relations contained in each type of procedure. The SCD procedure consisted of six blocks of three trials in Phase 1, nine blocks of two trials in Phase 2, and randomized trials in Phase 3. The CD procedure was identical to Phase 3 of SCD, but with other stimuli. The CD procedure was more efficient for establishing receptive language, but the SCD was more effective for maintaining the repertoire. The implications of these results for the applied area and directions for future research are discussed.

Behavioral inhibition during a conflict state elicits a transient decline in hippocampal theta power.

Although it has been shown that hippocampal theta power transiently declines during response inhibition in a simultaneous feature negative (FN: A+, AB-) task, observations of additional changes after this initial decline have been inconsistent across subjects. We hypothesized that the cause of these inconsistencies might be that variations in the learning speed for the FN task differentially affect the changes in hippocampal theta activity observed during the task. In this study, we classified rats into three groups (fast, intermediate, and slow FN-learning groups) based on the number of sessions required to complete learning of the FN task. We then examined whether there was a difference in hippocampal theta power among the fast, intermediate, and slow FN-learning groups, and rats that learned a simple discrimination task (SD group). We observed that compared to the SD group, the slow FN-learning group, but not the fast FN-learning group, showed an increase in hippocampal theta power. In addition, a transient decline of hippocampal theta power occurred in the fast FN-learning group, but not in the slow FN-learning group. These results indicate that the hippocampal theta activity during response inhibition in the FN task differed between fast- and slow-learning rats. Thus, we propose that a difference in learning speed affected hippocampal theta activity during response inhibition under a conflict state.

Change in hippocampal theta activity during behavioral inhibition for a stimulus having an overlapping element.

It is believed that a decline in hippocampal theta power is induced by response inhibition for a conflict stimulus having an overlapping element. This study used a simultaneous feature positive (simul FP: A-, AX+) task and a serial FP (A-, X→A+) task. In these tasks, the compound and single stimuli have an overlapping element, and rats are required to exhibit response inhibition for the single stimulus A. We examined hippocampal theta activity during simul FP (A-, AX+), serial FP (A-, X→A+), and simple discrimination (SD; A-, X+) tasks and revealed that the transient decrease in hippocampal theta power occurred during response inhibition for the single stimulus A in simul FP tasks, which provides evidence that a transient decline in hippocampal theta power is induced by behavioral inhibition of conflict stimuli having an overlapping element. Thus, we concluded that the transient decline in hippocampal theta power was induced by behavioral inhibition for the conflict stimulus having an overlapping element.

Change in hippocampal theta activity with transfer from simple discrimination tasks to a simultaneous feature-negative task.

It was showed that solving a simple discrimination task (A+, B-) and a simultaneous feature-negative (FN) task (A+, AB-) used the hippocampal-independent strategy. Recently, we showed that the number of sessions required for a rat to completely learn a task differed between the FN and simple discrimination tasks, and there was a difference in hippocampal theta activity between these tasks. These results suggested that solving the FN task relied on a different strategy than the simple discrimination task. In this study, we provided supportive evidence that solving the FN and simple discrimination tasks involved different strategies by examining changes in performance and hippocampal theta activity in the FN task after transfer from the simple discrimination task (A+, B- → A+, AB-). The results of this study showed that performance on the FN task was impaired and there was a difference in hippocampal theta activity between the simple discrimination task and FN task. Thus, we concluded that solving the FN task uses a different strategy than the simple discrimination task.

Exclusion performance in visual simple discrimination in dogs (Canis familiaris)

Choices based on exclusion have been investigated in different species because of its emergent nature, leading to evidence of rudimentary symbolic behavior in non-verbal organisms. Simple discrimination procedures provide a simple method to investigate exclusion performance, in which each trial consists of the simultaneous presentation of two stimuli, one with a positive function (S+) and one with a negative function (S-). In exclusion probe trials, an undefined stimulus (UnS) is presented with a familiar S-, and choices based on exclusion may lead to choosing the UnS, excluding the previously known S-. Novelty control trials (S+/UnS) are also conducted to assess the possible preference for the UnS. In this case, if performance is not controlled by novelty, then the subjects must choose the S+ and not the UnS. The present study investigated exclusion performance in visual simple simultaneous discrimination tasks in eight dogs. The results indicated that seven of eight dogs showed evidence of exclusion performance (p < .05). These findings corroborate the literature that shows that dogs are capable of responding by exclusion, suggesting that potentially symbolic behavior may rely on basic behavioral learning and conditioning principles.(AU)

Exclusion performance in visual simple discrimination in dogs (Canis familiaris)

Choices based on exclusion have been investigated in different species because of its emergent nature, leading to evidence of rudimentary symbolic behavior in non-verbal organisms. Simple discrimination procedures provide a simple method to investigate exclusion performance, in which each trial consists of the simultaneous presentation of two stimuli, one with a positive function (S+) and one with a negative function (S-). In exclusion probe trials, an undefined stimulus (UnS) is presented with a familiar S-, and choices based on exclusion may lead to choosing the UnS, excluding the previously known S-. Novelty control trials (S+/UnS) are also conducted to assess the possible preference for the UnS. In this case, if performance is not controlled by novelty, then the subjects must choose the S+ and not the UnS. The present study investigated exclusion performance in visual simple simultaneous discrimination tasks in eight dogs. The results indicated that seven of eight dogs showed evidence of exclusion performance (p < .05). These findings corroborate the literature that shows that dogs are capable of responding by exclusion, suggesting that potentially symbolic behavior may rely on basic behavioral learning and conditioning principles...

Impaired executive function following ischemic stroke in the rat medial prefrontal cortex.

Small (lacunar) infarcts frequently arise in frontal and midline thalamic regions in the absence of major stroke. Damage to these areas often leads to impairment of executive function likely as a result of interrupting connections of the prefrontal cortex. Thus, patients experience frontal-like symptoms such as impaired ability to shift ongoing behavior and attention. In contrast, executive dysfunction has not been demonstrated in rodent models of stroke, thereby limiting the development of potential therapies for human executive dysfunction. Male Sprague-Dawley rats (n=40) underwent either sham surgery or bilateral endothelin-1 injections in the mediodorsal nucleus of the thalamus or in the medial prefrontal cortex. Executive function was assessed using a rodent attention set shifting test that requires animals to shift attention to stimuli in different stimulus dimensions. Medial prefrontal cortex ischemia impaired attention shift performance between different stimulus dimensions while sparing stimulus discrimination and attention shifts within a stimulus dimension, indicating a selective attention set-shift deficit. Rats with mediodorsal thalamic lacunar damage did not exhibit a cognitive impairment relative to sham controls. The selective attention set shift impairment observed in this study is consistent with clinical data demonstrating selective executive disorders following stroke within specific sub-regions of frontal cortex. These data contribute to the development and validation of a preclinical animal model of executive dysfunction, that can be employed to identify potential therapies for ameliorating cognitive deficits following stroke.

Simple and Conditional Discrimination and Specific Reinforcement in Teaching Reading: An Intervention Package.

This study evaluated an intervention package combining simple and conditional discrimination training and specific reinforcement for each stimulus class in teaching reading of simple words to individuals with intellectual disabilities. In conditional discrimination training, participants matched printed words and pictures to the recorded sounds made by the pictured objects and animals. Fourteen children and adolescents with intellectual disabilities were assigned to an experimental and a control group. The two groups' performance did not differ in the pretest. The experimental group demonstrated equivalence class formation and read the words that participated in the equivalence classes, whereas the control group did not.

Beta-adrenergic antagonist effects on a novel cognitive flexibility task in rodents.

Previous work examining animal models of cognitive flexibility have focused on tasks where animals are required to shift between cues in order to reach a food reward from among a limited set of choices. Performance by nonhuman animals on these tasks, including reversal learning, intradimensional set-shifting, and extradimensional set-shifting, are affected by pharmacological action on serotonergic, dopaminergic, and alpha-adrenergic, but not beta-adrenergic receptors. However, beta-adrenergic antagonists, such as propranolol, are widely utilized for conditions such as test anxiety. Propranolol improves performance in humans during cognitive flexibility tasks where there is a broad set of potential solutions. The current investigation utilized a digging task where the rodent must develop a novel solution in order to obtain a reward. Similar to the effects observed in humans, propranolol improved performance on this task, while not affecting performance on set-shifting tasks, as with previous animal studies. This may allow future investigation of the neurobiological mechanism by which propranolol affects context-specific anxiety, and could provide insight into the neurobiology of creativity.

Discriminações simples, classes funcionais e classes de equivalência / Simple discriminations, functional classes and equivalence classes

O presente estudo procurou investigar se procedimentos de discriminações simples, que produzem classes funcionais, poderiam produzir também classes de equivalência. No Experimento 1 utilizou-se o procedimento de discriminações simples sucessivas e reversões. Quatro adultos foram expostos ao treino em que respostas aos estímulos S+ (A1, B1 e C1), mas não aos S- (A2, B2 e C2), eram reforçadas. A seguir, os participantes eram expostos a reversões repetidas das contingências. Testes de relações condicionais emergentes (BA, CB, AC e CA) foram conduzidos por meio do procedimento go/no-go com estímulos compostos, para evitar que os testes envolvessem sequências de respostas possivelmente reforçadas no treino anterior. Os quatro participantes apresentaram responder consistente com a formação de classes funcionais e, três deles, também apresentaram responder indicativo da formação de classes de equivalência. O Experimento 2, investigou se um procedimento de discriminações simples, estabelecidas por meio de respostas diferenciais, que evitava o estabelecimento de sequências de respostas ou discriminações condicionais inadvertidamente, produziria classes funcionais e de equivalência. Outros quatro adultos típicos foram expostos ao treino, em que a Reposta 1 (R1) era reforçada apenas quando emitida na presença de A1, B1 e C1, enquanto a Resposta 2 (R2) era reforçada apenas na presença de A2, B2 e C2. A seguir, uma nova resposta era treinada na presença de um estímulo de cada classe (A1-R3 e A2-R4). Por fim, foram conduzidos Testes de transferência de função e Testes de relações condicionais emergentes (AB, BC, BA, CB, AC e CA) por meio do procedimento go/no-go com estímulos compostos(AU)

This study investigated if simple discrimination procedures, which produce functional classes, could also produce equivalence classes. In Experiment 1, a simple successive discrimination reversal training was used. Four adults were exposed to training in which responses to S+ (A1, B1 and C1), but not to S- (A2, B2 and C2), were reinforced. Next, the participants were exposed to repeated-reversal training. Finally, Emergent conditional relations Tests (BA, CB, AC and CA) were conducted using the go/no-go procedure with compound stimuli to avoid tests involving response sequences adventitiously reinforced during the previous training. The four participants responded consistently with functional class formation and three of them also showed performance indicative of equivalence class formation. Experiment 2 investigated whether a simple discrimination training via differential responses would produce functional and equivalence classes. This training procedure avoided the inadvertently establishment of conditional discriminations or response sequences. Four additional adults were exposed to training procedure in which Response 1 (R1) was reinforced only when emitted in the presence of A1, B1 or C1 and Response 2 (R2) was reinforced only in the presence of A2, B2 or C2. Next, a new response was trained in the presence of one member of each class (A1-R3, A2-R4). Finally, a Transfer of function Test and Emergent conditional relations Tests (AB, BC, BA, CB, AC e CA) were conducted(AU)

Medidas de Controle de estímulos: fixações do olhar como respostas de observação naturais / Measurement of stimulus control: eye fixations as natural observing responses

Análises dos movimentos dos olhos frequentemente apresentam resultados inconclusivos sobre a função discriminativa dos estímulos que estes movimentos produzem. Esta pesquisa objetivou apresentar a análise da primeira fixação dos olhos de participantes em cada componente de uma tarefa de discriminação simples sucessiva como indicadora das funções discriminativas de dois conjuntos de estímulos. Quatro universitários foram submetidos a tarefas de discriminação em que respostas em um teclado produziram pontos quando emitidas diante de um conjunto de estímulos, mas não de outro. O olhar dos participantes foi rastreado. Realizaram-se análises da frequência total, duração total, duração média e duração da primeira fixação dos olhos dos participantes sobre os SDs. A duração da primeira fixação se mostrou mais preditiva das diferentes funções dos conjuntos de estímulos antecedentes à tarefa manual. Os resultados são discutidos em termos das características dinâmicas dos estímulos e da importância de análises dos movimentos dos olhos no âmbito aplicado.(AU)

Behavior analyses of eye movements frequently present non-conclusive results about discriminative functions of the stimuli produced by these movements in relation to following responses. This paper presents an analysis of the first fixation of the eyes of the participants on each component during a simple, successive discrimination task as indicative of discriminative functions of two stimuli sets. Four undergraduate students were separately submitted to a simple, successive discrimination task in which space bar pressing on a computer keyboard produced points when emitted during presentation of stimuli of one set but not during presentation of stimuli of a second set. After discriminative control of bar pressing was achieved discriminative functions were reverted. Eye movements of participants were tracked during session. Analyses of total frequency, total duration, average duration, and first duration of eye fixations of the participants toward each set of discriminative stimuli were made. Duration of first fixation was more predictive of the different discriminative functions of antecedent stimuli to manual task. Results are discussed in terms of dynamic characteristics of stimuli and of the relevance of eye movements for applied sets.(AU)