Subjective contours produced purely by dynamic occlusion of sparse-points array

Abstract

In this paper, I describe the formation of a classic subjective contour by the occlusion of moving points of light having very sparse spatial distribution. In move and flash conditions, subjects determined what contour circumscribed the display region in which the points of light appeared. Subjects felt that the subjective contours were sharp and of distinct shape in the move condition if there were at least six impacts with the edges per second. No occluding subjective form was evident in the flash condition, although the delineation of an edge was more cogent than in the move condition.