Recent research using the event-related potential (ERP) technique has shown that equivalence relations have properties similar to genuine semantic relations. This study aimed to advance electrophysiological investigations of the functional overlap between semantic and equivalence relations. The N400 component, an index of semantic processing, was used to measure whether semantic relations were experimentally established between arbitrary stimuli. The stimuli became equivalent via a matching-to-sample training designed to maximize the establishment of equivalence relations and the strength of the classes. Non-equivalent pairs of stimuli elicited larger N400 responses than equivalent pairs in electrodes placed over the central and parietal scalp regions, providing additional support for the assumption that stimulus equivalence is an appropriate model of semantic relations. Latency of the N400 component was shorter than in previous studies, probably due to experimental parameters that maximized relational strength. These data raise the possibility that N400 latency may provide a continuous measure of relational strength, thus supplementing the all-or-none character of equivalence tests based on matching to sample.

The present study investigated whether overtraining of the conditional discriminations that are the prerequisites of equivalence class formation strengthens the relations among stimuli in an equivalence class. Two groups of college students formed equivalence classes that consisted of faces that expressed emotions (A) and arbitrary stimuli (B, C, D, and E). The overtraining group had twice as many training trials as the regular training group. For participants who formed equivalence classes, relational strength was evaluated by the generalization of expressed emotions from the A to the D stimuli, which was measured using a semantic differential. An untrained control group showed semantic differential scores that were positive for happy faces, negative for angry faces, and neutral for the D stimuli. For the experimental groups, the D stimuli, when included in equivalence classes, produced scores that were similar to those produced by the equivalent faces. The overtraining group, however, had average values closer to the values of the faces than the regular training group. These results indicate that the amount of training is an experimental parameter that influences the strength of relations between stimuli that are found to be equivalent in matching-to-sample tests.

The purpose of this study was to verify discriminative control by segments of signs in adolescents with deafness who use Brazilian Sign Language (BSL). Four adolescent with bilateral deafness, with 3 years of BSL teaching, saw a video presenting a children's tale in BSL. After showing accurate understanding of the story, participants saw another video of the same story with 12 signs altered in one of their segments (hand configuration, place of articulation, or movement). They apparently did not detect the alterations. However, when the signs were presented in isolation in a matching-to-sample test, they virtually always selected the picture corresponding to the unaltered signs. Three participants selected an unfamiliar picture in 50% or more trials with an altered sign as a sample, showing that they could detect the majority of the altered signs.

Este estudo relata o emprego de um sistema lingüístico em miniatura para investigar a aprendizagem de leitura. Vinte estudantes de graduação (10 da área de exatas e 10 de humanas) aprenderam a relacionar figuras e pseudo-palavras impressas às correspondentes pseudo-palavras ditadas, em tarefas de discriminação condicional realizadas em computador. Sessões de ensino foram intercaladas com testes de leitura de palavras novas, formadas pela recombinação de elementos das palavras ensinadas (generalização recombinativa). Nove estudantes de exatas e quatro de humanas apresentaram leitura recombinativa após a aprendizagem de 12 palavras. Os escores em leitura de palavras novas aumentaram à medida que aumentava o número de palavras ensinadas. Ambos os achados podem ser interpretados como efeitos de experiências de aprendizagem com relações simbólicas. As diferenças entre estudantes das áreas de humanas e exatas podem também refletir fatores motivacionais.

This study reports the use of a miniature linguistic system in order to investigate reading acquisition. Twenty college students, 10 from Natural Sciences and Engineering (NSE) and 10 from Health and Social Sciences (HSS) courses, learned to relate pictures and printed pseudo-words to dictated pseudo-words in conditional discrimination tasks presented by a computer. Teaching sessions were interspersed with tests of reading new words formed by recombination of elements of taught words (generative recombination). Nine students from NSE and four from HSS developed generalized reading after learning 12 relations with pseudo-words. Reading scores of new words increased as number of taught words increased. Both findings could be interpreted as effects of learning experiences with symbolic relations. Differences between the NSE and the HSS students could also reflect motivational factors.

O responder por "exclusão', que se supõe ser um dos mecanismos pelos quais crianças aprendem a relacionar palavras novas a objetos ou eventos, tem sido amplamente replicado em situação de laboratório. O presente estudo, conduzido com seis crianças, teve por objetivo investigar o responder por exclusão em um contexto de brincadeira, com estímulos manipuláveis, e verificar se este contexto favorece a aprendizagem da relação nome - objeto, após uma única tentativa de exclusão. Em cada tentativa o experimentador falava o nome de um brinquedo conhecido e a tarefa da criança era pegá-lo e jogá-lo dentro de uma caixa grande, disposta à frente da criança. Em meio a essas tentativas, eram introduzidas três sondas de exclusão (o nome falado era novo e havia um brinquedo novo exposto no ambiente); três outras sondas verificavam se a relação entre o nome e o brinquedo havia sido aprendida. Todas as crianças responderam por exclusão, mas somente uma mostrou aprendizagem após uma única tentativa.

Laboratory studies have repeatedly replicated the phenomenon of exclusion responding, which has been assumed as one of the mechanisms by which children learn to relate novel words to objects or events. The present study, conducted with six children, aimed to investigate exclusion responding in a play setting, with stimuli that could be manipulated, and to verify whether the play setting would favor learning of the relationships between names and objects after a single exclusion trial. In several trials the experimenter spoke the name of a familiar toy and the child's task was to pick this toy up and throw it into a box, placed in front of the child. Three exclusion probes were interspersed among these trials (the spoken name was novel and there was a novel toy available); three other probes verified whether the relationships between the novel name and the toy had been learned. All children responded by exclusion but only one of them demonstrated learning the relationships in a single trial.

Este estudo apresenta um procedimento para verificar a existência de "graus de relacionamento" diferentes entre estímulos equivalentes por meio de uma medida quantitativa de compartilhamento de funções. Dois grupos de estudantes universitários participaram do estudo. Os participantes do grupo experimental estabeleceram classes de equivalência entre figuras abstratas e fotografias de faces expressando alegria, raiva e nojo. Em seguida, avaliaram algumas das figuras abstratas usando um instrumento de diferencial semântico. O mesmo instrumento foi utilizado na avaliação das faces e figuras pelos participantes do grupo controle, não treinados a estabelecer relações entre esses estímulos. Esses últimos participantes avaliaram as figuras como neutras e as avaliações que fizeram das faces corresponderam às avaliações das figuras equivalentes a elas feitas pelos participantes do grupo experimental. A comparação entre os valores atribuídos às faces e às figuras dá uma medida quantitativa do grau de relacionamento entre esses estímulos e essa medida pode ser usada no estudo de parâmetros da formação de classes como o número de nódulos.

There are methodological difficulties to quantify the relatedness of equivalent stimuli. The purpose of this study was to create an instrument that could be helpful in this process. Two groups of college students took part in this study. The experimental group established equivalence classes comprised of abstract pictures and pictures of faces expressing anger, happiness and disgust. They then evaluated some of these pictures with a semantic differential. The control group used the same instrument in evaluating faces and figures, untrained in establishing relations between those stimuli. The control group assessed the figures as neutral and their assessment of the faces corresponded to that carried out by the participants of the experimental group - to them, the figures were equivalents to the faces. The comparison between the values attributed to the faces and figures provides a quantitative measurement of the degree of relatedness between those stimuli and that may be used to study parameters such as the number of nodes.

Este estudo efetuou uma avaliação preliminar da eficácia de um programa educacional de estímulo ao aleitamento materno, que inclui a introdução simultânea de técnicas de estimulação do bebê. O programa, elaborado por Garcia-Montrone (1992), foi aplicado a um grupo de mães de nível sócio-econômico baixo (grupo experimental). Tal programa foi avaliado através de sessões de observação direta da interação mãe-criança e entrevistas com as mães até seis meses após o nascimento do bebê, comparando-se os resultados com os de um grupo-controle com características similares de idade, nível educacional e experiência prévia em amamentação. Cada grupo continha inicialmente dez díades, havendo um abandono em cada grupo durante o estudo. Os resultados mostraram que 55% das mães do grupo experimental ainda amamentavam seus filhos aos seis meses, contra apenas 22% daquelas do grupo-controle. Em relação à estimulação do bebê, o grupo experimental mostrou uma freqüência significativamente maior de episódios de estimulação que o grupo-controle. Os autores concluem que é factível incluir simultaneamente aleitamento materno e estimulação do bebê num programa educacional para mulheres de nível sócio-econômico baixo e que a aplicação deste programa pode contribuir para reduzir o risco de desnutrição e retardo do desenvolvimento do bebê.

This study included a preliminary analysis of the effectiveness of an educational program on breast-feeding and infant stimulation techniques. The program, developed by Garcia-Montrone (1992), was applied to a group of mothers (experimental group) of low socio-economic status. The program was evaluated by direct observation of mother-infant interaction and interviews with the mothers up to six months after childbirth. Results were compared with a control group of women matched for age, educational level, and previous experience with breast-feeding. Each group began with 10 mother-infant dyads, and there was one withdrawal in each group over the course of the study. 55% of the mothers in the experimental group were still breast-feeding six months after childbirth, compared to 22% in the control group. The experimental group also showed a significantly higher frequency of stimulation of the infant, both during and after breast-feeding. The authors conclude that it is feasible to combine breast-feeding and infant stimulation instruction in an educational program for women of low socio-economic status and that the use of this program can help reduce risk factors both for malnutrition and developmental retardation.

Este estudo efetuou uma avaliação preliminar da eficácia de um programa educacional de estímulo ao aleitamento materno, que inclui a introdução simultânea de técnicas de estimulação do bebê. O programa, elaborado por Garcia-Montrone (1992), foi aplicado a um grupo de mães de nível sócio-econômico baixo (grupo experimental). Tal programa foi avaliado através de sessões de observação direta da interação mãe-criança e entrevistas com as mães até seis meses após o nascimento do bebê, comparando-se os resultados com os de um grupo-controle com características similares de idade, nível educacional e experiência prévia em amamentação. Cada grupo continha inicialmente dez díades, havendo um abandono em cada grupo durante o estudo. Os resultados mostraram que 55% das mães do grupo experimental ainda amamentavam seus filhos aos seis meses, contra apenas 22% daquelas do grupo-controle. Em relação à estimulação do bebê, o grupo experimental mostrou uma freqüência significativamente maior de episódios de estimulação que o grupo-controle. Os autores concluem que é factível incluir simultaneamente aleitamento materno e estimulação do bebê num programa educacional para mulheres de nível sócio-econômico baixo e que a aplicação deste programa pode contribuir para reduzir o risco de desnutrição e retardo do desenvolvimento do bebê.

This study included a preliminary analysis of the effectiveness of an educational program on breast-feeding and infant stimulation techniques. The program, developed by Garcia-Montrone (1992), was applied to a group of mothers (experimental group) of low socio-economic status. The program was evaluated by direct observation of mother-infant interaction and interviews with the mothers up to six months after childbirth. Results were compared with a control group of women matched for age, educational level, and previous experience with breast-feeding. Each group began with 10 mother-infant dyads, and there was one withdrawal in each group over the course of the study. 55% of the mothers in the experimental group were still breast-feeding six months after childbirth, compared to 22% in the control group. The experimental group also showed a significantly higher frequency of stimulation of the infant, both during and after breast-feeding. The authors conclude that it is feasible to combine breast-feeding and infant stimulation instruction in an educational program for women of low socio-economic status and that the use of this program can help reduce risk factors both for malnutrition and developmental retardation.