Abstract
Tracking eye movements not only require an estimate of target motion but also predictions regarding the trajectory. In the present contribution we propose that this visuo-motor transformation takes into account prior information about object kinematics in the real world. In particular, the force of gravity constrains round objects to roll on the ground with particular rotational and translational speeds. We asked observers to track two different kinds of rotating discs, each one having the same visual motion energy at any point in time. Objects rotated in a direction that was either congruent or incongruent with their linear trajectory on the ground. For instance, a disk moving to the right and rolling clockwise has congruent linear and rotational directions of motion, while a disk moving to the right and rolling counterclockwise has incongruent directions of motion. The incongruent object has a "backspin" and appears to slip (not to roll) on the surface. In support of our hypothesis, the initial phase of tracking eye movements was slightly faster in the congruent compared to the incongruent condition.
Meeting abstract presented at VSS 2012