Role of cerebral hemispheres and regions in processing hemifacial expression of emotion: evidence from brain-damage.

Patients with focal brain-damage, right or left hemisphere-damage (RHD/LHD) and anterior or posterior region-damage (ARD/PRD), and normal controls (NC) were asked to match the photographs of (left-right) hemifacial expressions of emotions, positive (happy-surprise), negative-aroused (fear-anger), negative-nonaroused (sad-disgust). Findings indicated that (a) NC subjects were significantly superior to brain-damaged patients; the difference between RHD and LHD patients was nonsignificant, and (b) ARD patients were significantly inferior to PRD patients who, in turn, were significantly inferior to NC subjects, in the perceptual matching task with hemifacial affective stimuli.