Affective processing in left and right hemisphere brain-damaged subjects with and without subcortical involvement

Affective processing ability was examined in right and left hemisphere brain-damaged subjects with cortical lesions that were grouped according to the presence or absence of concomitant subcortical basal ganglia damage. The ability to process affective speech prosody, emotional facial expressions, and linguistically coded emotional messages was measured in isolated identification tasks. Results indicated that subjects with damage to subcortical structures in addition to cortical left or right hemisphere brain damage had difficulty processing emotional words, facial expressions, and prosodic intonations. Subjects with cortical damage only, regardless of side of lesion (left or right), performed without significant difficulty across all tasks. There were hemispheric differences found in the cortical-subcortical groups. The left cortical-subcortical subjects had the greatest difficulty processing linguistic information and the right cortical-subcortical subjects had the most difficulty processing facial expression and prosodic information. Findings support the connection between higher- and lower-order brain structures in processing messages that are affectively coded.