THE MINIMAL EFFECT OF OCCLUSION ON PERCEIVED DEPTH FROM MOTION PARALLAX

Two experiments tested the ability of subjects to perceive the depths of three-dimensional (3-D) objects oscillating behind a series of occl uding bars. Occlusion was manipulated by the spatial period of the occ luding bar series as well as by its duty cycle (the proportion of fiel d of view that was not occluded). It was found that the estimates of p erceived 3-D shape from motion parallax were remarkably unaffected whe n the projected image of a rotating 3-D object was partially occluded. Occlusion of 60% of the object had little effect on perceived shape, as judged by estimates of perceived depth, and even occlusion of 90% o f the object produced only slight reductions in perceived depth in man y cases. It was also found that even when there were no obvious occlud ing boundaries, judgments of depth were relatively unaffected.