Abstract

Human stereoscopic vision may provide precise information about 3-D structure. Fundamental theoretical questions concern the specific geometric properties of monocular stimulation that carry visual information for stereopsis. Recent evidence on the stereoscopic acuity for moving patterns indicates that perceived 3-D structure derives from disparities between the monocular optical fields, rather than from disparities between retinal positions of individual points, and from the self-congruence of spatiotemporal form.¹ The spatial structures in previous experiments, however, were rigidly moved. The present experiment tested the necessity for rigid motion. Optical patterns consisted of four dots (initially collinear and equally spaced—30 min of arc) undergoing bending motion in a plane tilted in depth. The task was to detect the depth displacement of a single dot from this continually changing curve. Observers detected displacements < 10-sec of arc disparity as accurately for bending curves as for stationary straight lines. Thus, stereoscopic acuity derives from the self-congruence of even nonrigidly moving form.

© 1986 Optical Society of America