The development of perceptual completion abilities: infants' perception of stationary, partially occluded objects.

We explored infants' ability to perceive stationary, partially occluded objects as connected units (Experiments 1 and 2) with specific appearances (Experiment 3). In each experiment, the infants saw 2 test events involving what appeared to adults to be a tall rectangular object whose middle portion was hidden behind a narrow screen. During the test events, the screen alternately uncovered and covered the object.

Children's use of frames of reference in communication of spatial location.

The frames of reference used by 4-, 6-, and 8-year-old children were studied in a spatial direction-giving task. Children were asked to specify verbally the location of a toy hidden under one of several identical cups. The child and listener sat facing each other at opposite ends of a room that had distinctive or nondistinctive landmarks proximal and distal to the hiding location.

Kinetic occlusion: further studies of the boundary-flow cue.

Previous work has demonstrated that human beings employ a processing assumption, the boundary-flow constraint, in perceiving the order of depth at an edge. Subjects perceive depth order of surfaces on the basis of the relative motions of an image boundary and a projected surface texture on either side of the boundary. In the present study, adult subjects viewed computer-generated kinematograms in which boundary-flow information provided the only cue for depth order.

Infants' sensitivity to boundary flow information for depth at an edge.

We investigated infants' sensitivity to a recently discovered kinetic depth cue, boundary flow. 5-month-old infants viewed computer-generated displays in which the relation between the motion of a boundary, indicating an edge, and 2 regions of dots on either side of the boundary, indicating surfaces, provided the only information specifying the order of the 2 surfaces in depth. Infants showed a significant reaching preference for the apparently nearer region of the display.