Examined object concept development in 2- to 4-year olds with a partial replication of a study by Spelke and Kestenbaum (1986). Found that children judged identical entering and exiting figures as involving one object and different figures as involving two objects. Continuity of movement failed to affect judgments of numerical identity. Findings…

Two experiments examined the effects of common motion, background texture, and orientation on four-month olds' perception of unity of a partially occluded rod. Results indicated that infants' perception of object unity is not dependent on a single visual cue but on a variety of cues including motion, interposition, depth cues, background texture,…

Three experiments examined 4- and 6-month-olds' sensitivity to the unity of a partly occluded moving rod undergoing translation, rotation, or oscillation. Findings suggested that all types of common motion were not equivalent for specifying infants' perceptions of occluded objects. (Author)

A fundamental question of perceptual development concerns how infants come to perceive partly hidden objects as unified across a spatial gap imposed by an occluder. Much is known about the time course of development of perceptual completion during the first several months after birth, as well as some of the visual information that supports unity…