BINOCULAR EYE-MOVEMENTS CAUSED BY THE PERCEPTION OF 3-DIMENSIONAL STRUCTURE-FROM-MOTION

We report that the perception of three-dimensional structure from mono cular two-dimensional images changing over time-the kinetic depth effe ct (KDE)-can evoke binocular eye movements consistent with a three-dim ensional percept. We used a monocular KDE stimulus that induced a vivi d perception of a rigid three-dimensional sphere rotating in space, Th e gaze directions of both eyes were measured while observers pursued t he motion of a patch on the surface of the perceived sphere as it went through a complete revolution. We found that the eyes converged when the patch was perceived on the front surface of the KDE sphere and div erged when the patch was perceived in the back. The pattern, magnitude and dynamics of binocular eye movements observed in the KDE experimen t resembled those obtained when subjects viewed binocularly a light-em itting diode (LED) rotating in space and to the responses obtained wit h a dynamic stereogram simulating a rotating random dot sphere. Thus, the perception of three-dimensional structure from motion, stereopsis, or motion and stereopsis combined, were effective in guiding binocula r eye movements. Copyright (C)1996 Elsevier Science Ltd.