Developmental changes in the effect of dimensional salience on the discriminability of object relations.

Two experiments explored three issues regarding the nature of perceptual development in 5- and 10-year-old children and adults: (a) the role of featural discriminability, (b) the facilitatory role of identity relations, and (c) the role of salience in a task context designed to minimize the likelihood of attention-switching between dimensions during perceptual processing. In Experiment 1, perceptual salience for size and achromatic color dimensions was determined for each participant based on their best-fitting triad classification task response pattern. These same persons participated in Experiment 2, which employed a speeded visual discrimination task. The primary finding was that preassessed salience significantly influenced the 5-year-olds' ability to discriminate between two objects, while salience did not affect 10-year-olds' or adults' response times. The results of both experiments support Odom & Cook's (1992) differential-sensitivity view of perceptual development, but these data contribute important information by showing that salience effects in perceptual processing occur even when the observer is selectively attending to a particular dimension, likely during early component processes prior to classification. Copyright 1998 Academic Press.