Fig. 14. Reaching and pointing to visual targets in a case of optic ataxia are shown. The patient is a 65-year-old man with severe vertebrobasilar vascular disease. First he had a left occipital lobe infarction causing a right homonymous hemianopia. Next he had a large infarction of the right parietal lobe, which included the angular gyrus. Subsequently, his behavior resembled that of Balint's patient. To demonstrate optic ataxia, the patient is viewed from above as he reaches for highly visible targets located at arm's length to the left and right of body midline. The recordings use an optoelectronic technique to track an infrared-emitting diode fastened to the dorsum of each index fingertip. Multiple reaches are shown with the left hand and right hand. All movements begin from the same midline position just anterior to the patient. Head movement is unrestricted. Notice that the paths of the hand movements are highly variable. Also, the end positions of the movements are highly inaccurate, especially to the left target. The patient's hand movements were improved for reaches to self-bound targets such as his own nose (not shown), a task that depends more on kinesthetic than visual guidance. (Rizzo M: Balint's syndrome and associated visuospatial disorders. In Kennard C (ed): Balliere's International Practice and Research, pp 415–437. Philadelphia, WB Saunders, 1993)