Detection of contour continuity and closure in three-month-olds.

The present study used an operant conditioning procedure and contour integration stimuli to test three-month-olds' sensitivity to both contour continuity and contour closure. The data demonstrate an immaturity of continuity detection and a lack of closure detection at that age, relative to a previous finding of a heightened sensitivity to closed contours in adult observers. This finding modifies the general view of infant visual perception that has been more focused on the quantitative development of various aspects of visual perception, including contrast sensitivity, binocular disparity processing, perceptual completion, and other perceptual skills. These results suggest qualitative change in terms of the organization of visual information during development, and implications of this finding for visual maturation of mechanisms suggested to underlie these detection abilities are discussed.