EFFECT OF DISPARITY IN THE PERIPHERAL FIELD ON SHORT-LATENCY OCULAR FOLLOWING RESPONSES

Ocular following responses induced by brief movements of the visual sc ene were examined in monkeys for their dependence on disparity in the peripheral field. A random dot pattern was projected onto a tangent sc reen and partitioned into central and peripheral regions. Test stimuli were velocity steps applied in the central region, while stimuli in t he periphery were stationary. The visual images in the central region were seen always in the plane of the screen, while stimuli in the peri phery could be seen in front, behind, or in the plane of the screen (a chieved by a system of polarizing filters). Initial ocular following r esponses were larger when the peripheral stimuli were presented with a n uncrossed disparity than without disparity. On the other hand, respo nses were smaller when the peripheral stimuli were presented with cros sed disparity (<5.0 deg) than without disparity. The result is consist ent with the idea that ocular following responses are dependent on the perceived viewing distance.