Thirty college students attempted to form three 3-node 5-member equivalence classes under the simultaneous protocol. After concurrent training of AB, BC, CD, and DE relations, all probes used to assess the emergence of symmetrical, transitive, and equivalence relations were presented for two test blocks. When the A-E stimuli were all abstract…

Same-different categorization is a fundamental feat of human cognition. Although birds and nonhuman primates readily learn same-different discriminations and successfully transfer them to novel stimuli, no such demonstration exists for rats. Using a spatial discrimination learning task, we show that rats can both learn to discriminate arrays of…

The ability of preverbal infants to form and use ill-defined categories, to respond differentially to contrasting categories, and to use specific dimensions in learning these categories is examined in 20 infants 10 months of age. Results show that infants are not only capable of learning two ill-defined categories, but that they can do so with…

Examined representation of pictorial exemplars of humans by 3- and 4-month olds. Results demonstrated an asymmetry regarding the exclusivity of categorical representations formed for humans and non-human animals. Categorical representations for humans included exemplar information, whereas categorical representation for non-human animals was based…

The information processing terms "content" and "address" are used to describe structural differences between the constructs of individual identity and identity in the equivalence sense. In both cases a sameness relation is established in spite of specific differences. The resulting constructs of identity are known to be…

This study examined the ability of preschool children to process and use conceptual category information in a disrcimination learning task. A total of 60 boys and girls between the ages of 2 1/2 and 4 years completed a 3-choice discrimination learning task. On each of 12 trials, a child was presented with three magazine photographs: one of an…

How strategies affect learning of categories that lack necessary and sufficient attributes is explored. The authors propose that strategy variations induced by instructions affect only the amount of information represented about attributes, not processes operating on representations. An experiment required subjects to classify schematic faces into…

Two studies examined whether infants' category discrimination in an object-examination task was based solely on an ad hoc analysis of perceptual similarities among the experimental stimuli. Findings indicated that 10- to 11-month- olds' responses varied systematically only with the presence of a category change, but not with the degree of…

Looking times of 36 children were recorded during subject-controlled presentation of slides in order to determine whether the existence of simple categories in 3-year-olds can be inferred from habituation data, and to determine any sex differences in conceptual generalization of habituation. Habituation was demonstrated over repeated presentation…

Children often perseverate, repeating prior behaviors when inappropriate. This work tested the roles of verbal labels and stimulus novelty in such perseveration. Three-year-old children sorted cards by one rule and were then instructed to switch to a second rule. In a basic condition, cards had familiar shapes and colors and both rules were stated…

This study investigated the effects of two stimulus manipulations (spatial distinctness and number of dimensions) on the performance of 24 kindergartners and 24 fifth graders in (1) tasks requiring distributed attention and (2) tasks requiring selective attention. Results suggest that kindergartners attempt to use one processing mode (distributed…

Two experiments explored the nature of perceptual development in 5- and 10-year olds and adults. The primary finding was that preassessed salience significantly influenced 5-year olds' ability to discriminate two objects, while salience did not affect 10-year olds' or adults' response times. Results showed that salience effects in perceptual…