Proceedings of the Annual Meeting of the Cognitive Science Society

In order to process the reduced information in pointlight images of human movement, observers rely upon general processing heuristics as well as representations more specific to human gait This paper explores changes in the perception of structure from motion in young infants. W e re-examined data from 17 experiments, involving infants of 3- and S-months old, to determine which stimulus features of pointlight motion infants use to organize percepts, and how perception changes. By combining discrimination and encoding information w e provide a picture of developing perceptual processes. Five-month-olds encode the stimuli more quickly than 3-month-olds, while the younger infants discriminate pairs of stimuli more frequently. Infants of both ages use phase information to discriminate displays. Three-month olds discriminate canonical forms from modified forms when the stimuli are organized about a vertical axis, whereas S-month olds discriminate these f a m s only when one of the figures take on a human-like configuration. These results support a view in which differential skill in what is encoded characterizes development Furthermore, this work may help guide the integration of theory-formation models with heuristic and constraint-based models, into a more complete account of perception.