Four experiments assessed converging aspects of four-month-old infants' perceptions of visual patterns. Results together corroborate and extend previous findings that vertical symmetry has a special status in early perceptual development and that infants can perceive pattern wholes. (Author/AS)

In three experiments, nine-month-old infants were trained to fixate on a particular feature in a pair of stimuli that varied along three dimensions. In a fourth experiment, infants were trained to fixate on a stimulus compound until reaching a learning criterion. Infants' discrimination learning under these conditions implied an ability to attend…

Subjects were trained against their initial dimensional preference in a two-dimensional simultaneous discrimination learning task. (RH)

Following a review of the literature on responses of autistic persons to environmental stimulation, three experiments are detailed which examine the relationship between modality preference and rate of acquisition of a discrimination task. First, seven autistic children's preference for colored lights and/or simple tones was assessed in a sensory…

Investigates the dominance of global versus local visual properties in four-month-old infants as a function of individual differences in fixation duration. Suggests that long-looking infants process visual information more slowly than short-looking infants, and there may be qualitative differences in the manner in which the two groups of infants…

The present study examines the relationship between alternation behavior and performance, and in addition, the effects of reinforcement configuration and relevant dimension upon the use of alternation strategies in probability learning. Also investigated is the hypothesis that children's errors at terminal levels of performance in a two-choice…

Evaluates the efficacy of two training procedures for eliminating selective stimulus control observed with three trainable mentally retarded children. In another experiment, improvements in stimulus control were not a function of varying degrees of difficulty between stimulus sets or of a prior history of discrimination training with the less…

Describes two experiments conducted to explain why retarded children of younger mental age appear to be more selective on discrimination tasks containing relevant redundant cues than do children of older mental age. Findings are consistent with the hypothesis that the latter group of children are overselective because they tend to solve…

This brief report attempts to resolve the claim that infants preferentially attend to continuous variables over number [e.g. Psychol. Sci. 10 (1999) 408; Cognit. Psychol.44 (2002) 33] with the finding that when continuous variables are controlled, infants as young as 6-months of age discriminate large numerical values [e.g. Psychol. Sci. 14 (2003)…

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…