Eye movements and motor programming in a Time-To-Contact task

In previous experiments investigating motor control in a Time-To-Contact task [Morya et al., 2003], events occurring 400-600 ms prior to contact (but not earlier or later) caused volunteers to anticipate their estimate of when contact occurred. Many such mislocalization or mistiming effects have been discussed in the literature [Nijhuan, 1994; van Beers et al. 2001]. In preliminary eye-tracking experiments [Morya et al. 2004], with a simplified version of the task, involuntary shifts in gaze suggested the presence of attentional shifts as volunteers prepared to respond, that might be associated with their anticipations. To better understand the factors involved in these observations, gaze was sistematically recorded changing the speed of the moving target, and with different instructions as to where the volunteers should look as they performed the Time-To-Contact task.