The effects of task complexity on motor performance in left and right CVA patients.

The effects of task complexity on movement ipsilateral to lesion were examined using the Fitts tapping task [Fitts, P.M., J. exp. Psychol. 47, 381-391, 1954]. Subjects were required to rapidly tap two targets, which were 1 or 4 cm wide. Twenty controls and ten left hemisphere and nine right hemisphere stroke patients were studied. Only the left hemisphere group showed significant deficits with greater impairment found in the wide target condition. Quantified CT scan analyses indicated lesion volume was similar between CVA groups, but the left hemisphere group's lesions were more anterior. The results are discussed in terms of inter- and intrahemispheric roles in open and closed loop movements.