SACCADE AMPLITUDE INFLUENCES POINTING MOVEMENT KINEMATICS

THE amplitude of open-loop pointing movements to step displacements in target position is influenced by the amplitude of simultaneously prod uced saccadic eye movements. The time course over which this occurs wa s addressed in the present study. Analysis of the pointing kinematics showed that saccade amplitude had its effect only during the initial a cceleration of the hand. Moreover, the magnitude of the initial accele ration was correlated with the difference in the onset times of the ey e and hand movements: the closer in time the saccadic and pointing res ponses were initiated the larger the initial hand acceleration. Taken together, these results demonstrate that saccades influence the kinema tics of simultaneously produced limb movements but only over a limited time frame. (C) 1998 Rapid Science Ltd.