Volitional selection of direction in the generation of anticipatory ocular smooth pursuit in humans.

Anticipatory smooth pursuit eye movements cannot normally be generated in the absence of a moving target. However, repeated presentation of identical target motion stimuli, preceded by warning cues, leads to the build up of anticipatory smooth pursuit prior to target onset. These anticipatory responses arguably depend more on motor habit than cognitive expectations. Here, we show that directional cues, concomitant with a timing cue, may be used to initiate predictive (velocity scaled) movements in response to target stimuli of random direction. Furthermore, we show stored velocity and timing information may be directionally transferred, thus allowing predictive movements in a novel direction. This demonstrates the internal origin of these movements and their volitional as opposed to reflexive nature.