Visuospatial performance in left-handed patients with unilateral brain lesions.

A test of visuospatial judgment was given to left-handed patients with lesions of either the right or left hemisphere. In right-handed patients impaired performance on the test has been found to be almost exclusively associated with right hemisphere disease, the performance of patients with left hemisphere disease being comparable to that of controls. The left-handed patients in this study showed the same performance pattern: a high proportion of patients with right hemisphere lesions performed defectively while all the patients with left hemisphere lesions performed on a normal level. Thus the findings are in accord with the conclusion that hemispheric cerebral organisation with respect to the mediation of visuospatial performance do not differ in right-handers and left-handers.