When human observers track the movements of their own hand with their gaze, the eyes can start moving before the finger (i.e., anticipatory smooth pursuit). The signals driving anticipation could come from motor commands during finger motor execution or from motor intention and decision processes associated with self-initiated movements. For the present study, we built a mechanical device that could move a visual target either in the same direction as the participants' hand or in the opposite direction. Gaze pursuit of the target showed stronger anticipation if it moved in the same direction as the hand, compared to that in the opposite direction, as evidenced by decreased pursuit latency, increased lead of the eye to target in positions, decreased saccade rate, and decreased delay at the movement reversal. Some degree of anticipation occurred for incongruent pursuit, indicating that there is a role for higher-level movement prediction in pursuit anticipation. The fact that anticipation was larger when target and finger moved in the same direction provides evidence for a direct coupling between finger and eye motor commands.
- Anticipatory smooth pursuit
- Ocular tracking of self-motion
- Congruency effect
- Eye-hand coordination
- Copyright © 2016, Journal of Neurophysiology