The canonical view of motor control is that distal musculature is controlled primarily by the contralateral cerebral hemisphere; unilateral brain lesions typically affect contralateral but not ipsilateral musculature. Contralateral-only limb deficits following a unilateral lesion suggest but do not prove that control is strictly contralateral: the loss of a contribution of the lesioned hemisphere to the control of the ipsilesional limb could be masked by the intact contralateral drive from the non-lesioned hemisphere. To distinguish between these possibilities, we serially inactivated the parietal reach region (PRR), comprising the posterior portion of medial intraparietal area (MIP), the anterior portion of V6a and portions of the lateral occipital parietal area (LOP), in each hemisphere of two monkeys (23 experimental sessions, 46 injections total) to evaluate PRR’s contribution to the contralateral reaching deficits observed following lateralized brain lesions. Following unilateral inactivation, reach r...