The effect of the gap paradigm on the latency of human smooth pursuit of eye movement.

When a temporal gap is introduced between the extinction of a central fixation target and the illumination of an eccentric target (the gap paradigm), normal human subjects initiate saccadic eye movements towards the eccentric target at lower latency than when there is no gap. The aim of this study was to examine the latency of human smooth pursuit eye movements using a modified gap paradigm. Smooth pursuit latency was reduced in gap tasks, and the magnitude of reduction was related to the duration of the gap. The distribution of smooth pursuit latencies was also altered. It thus appears that human smooth pursuit latency is modulated in a similar manner to saccade latency in gap tasks.