Effect of disparity in the peripheral field on short-latency ocular following responses

Ocular following responses induced by brief movements of the visual scene were examined in monkeys for their dependence on disparity in the peripheral field. A random dot pattern was projected onto a tangent screen and partitioned into central and peripheral regions. Test stimuli were velocity steps applied in the central region, while stimuli in the periphery were stationary. The visual images in the central region were seen always in the plane of the screen, while stimuli in the periphery could be seen in front, behind, or in the plane of the screen (achieved by a system of polarizing filters). Initial ocular following responses were larger when the peripheral stimuli were presented with an uncrossed disparity than without disparity. On the other hand, responses were smaller when the peripheral stimuli were presented with crossed disparity (< 5.0 deg) than without disparity. The result is consistent with the idea that ocular following responses are dependent on the perceived viewing distance.