Developmental mechanisms in the perception of object unity

Neonates seem to perceive two ends of a partly occluded rod as two separate objects. However, by 4 months of age infants often appear to perceive a similar stimulus as comprised of a single unified object. Little is known about the mechanisms of development underlying this change. We constructed four connectionist models of how perception of object unity might develop in human infants, based on experience with a variety of visual cues known to be important to infants' performance. After exposure to a simulated visual environment, all the models were able to perceive a partly occluded object as unified. A rich perceptual environment and the presence of units for internal representations were found to improve generalization of acquired unity knowledge. These results lend plausibility to mechanistic accounts of human perceptual development, based on learning the statistical regularities inherent in the normal visual environment.