PERTURBATION OF THE GRASP COMPONENT OF A PREHENSION MOVEMENT IN A SUBJECT WITH HEMIPARKINSONS DISEASE

The response to perturbation of the manipulation component during preh ension was assessed for both hands of a hemiParkinson and of a Control subject. With perturbed trials, the hemiParkinson showed the same pat tern as the Control: a reorganization of kinematic parameters and no i ncrease of movement time. However, for both limbs of the hemiParkinson subject there was a transition phase from precision grip to whole han d prehension-this was more pronounced for the affected limb. The manip ulation component did not show a delay of activation [2]. Thus the glo bal dysfunction in the performance of sequential movement patterns was related to aspects of task predictability.