A KINEMATIC ANALYSIS OF REACHING AND GRASPING MOVEMENTS IN A PATIENT RECOVERING FROM OPTIC ATAXIA

A detailed, kinematic analysis revealed subtle deficits in midline pointing and prehension in a patient showing good clinical signs of recovery from optic ataxia associated with bilateral parieto-occipital damage. Relative to control subjects, the patient tended to misreach to the left with her right hand, and to the right with her left hand on a pointing task. While reach kinematics were otherwise normal in the pointing task, they were markedly disturbed in a prehension task, in which reaching and grasping movements must be integrated. In addition, difficulties in making fine postural adjustments to the hands were still evident 17 months post-injury. These findings suggest an important role for the posterior parietal lobes in programming goal-directed manual movements, and have implications for current theories of motor control and visual perception.