Perception of three-dimensional structure from motion in monkey and man.

Information on motion is important for the determination of the three-dimensional (3-D) structure of the environment for both human and non-human primates. For example, if a person were to close one eye and look at an evenly illuminated, irregularly shaped object, he would be unlikely to guess its shape correctly. But if the object is moved about, the correct shape immediately becomes apparent. Little is known about how the primate visual system actually does this, although various theories have been proposed. We have developed novel, highly controlled motion stimuli to use with psychophysical and physiological techniques to study how 3-D structure is obtained from motion. We show that the Rhesus monkey can detect 3-D structure from motion in the same way as human subjects. Furthermore, the dependence of both species on certain parameters of the display shows that information is integrated both spatially and temporally for this higher visual function.