The role of internal models and prediction in catching balls

Abstract

There is considerable evidence for the role of internal models of the body’s dynamics in the control of movement. However, the existence of internal models of the environment is less well established. The present work provides further evidence of the existence of sophisticated internal models of the structure of the environment. We suggest that such models are used to predict upcoming events and plan movements in anticipation of those events. We recorded eye, head, and hand movements while subjects caught balls thrown with a bounce. Subjects initially fixate the hands of the thrower, then saccade to the anticipated bounce point, and then pursue the ball until it is close to the hands. However, ability to pursue the ball depends on experience with the ball’s dynamic properties.