A method is described to relate brain morphology and neuropsychological disturbances e.g., aphasia. By mapping lesions with computerized tomography onto a grid model of 5 brain slices, aphasiological information and lesion site are compared by data processing, allowing the quantitative and qualitative manipulation of a large number of data. The localization of aphasic disturbances was investigated. Data processing was performed on a preliminary group of 70 patients with different aphasic syndromes (Broca, Wernicke and global aphasics with and without recurring utterances). The typical locus of Wernicke''s aphasia was Wernicke''s area. The main lesion for Broca aphasics was in the insular cortex, with a relatively important participation of the frongal white matter. The implications of this refined method for more vigorous aphasiological and neuropsychological research are briefly indicated.