Motor SystemsStimulus predictability and the gap effect on pre-saccadic smooth pursuitKnox, Paul C.1Author Information 1Vision Sciences, Glasgow Caledonian University, City Campus, Cowcaddens Road, Glasgow G4 0BA, UK Received 12 November 1997; accepted 13 January 1998 NeuroReport: March 30th, 1998 - Volume 9 - Issue 5 - p 809-812 Buy Abstract THERE is disagreement in the literature as to whether smooth pursuit latency is reduced when a temporal gap is introduced between the extinction of a central fixation target and the illumination of an eccentric moving target. This study confirms that in human subjects smooth pursuit latency is reduced by gaps and that the magnitude of the reduction is related to the duration of the gap. However, latency is not solely determined either by visual factors or by task parameters such as spatial predictability, but is affected by task context. The results suggest a role for non-visual factors such as attention in the initiation of pursuit. © Lippincott-Raven Publishers.