THE NEUROPSYCHOLOGY OF EMOTION IN MAJOR DEPRESSIVE DISORDER (FACES, EMOTIONAL EXPRESSION)

Abstract

Thirty right-handed patients meeting Research Diagnostic Criteria for Major Depression were compared with 30 normal control subjects matched for age, sex and handedness in a study examining neuropsychological measures of emotional expression and perception focusing on the face. Previous studies implicating the right hemisphere in both normal and pathological affective processing have not included laterality measures specifically addressing emotion. A literature suggesting that normals display left hemiface dominance for muscular activity during posed emotional expression, and a left hemifield bias when making perceptual judgments from emotional faces indicated the need for such studies in patients with impaired affect.;Subjects were photographed using a 35 mm camera with a motor drive attachment while posing 4 emotional facial expressions: Happy, Sad, Disgust, Surprise. Naive raters chose the frame of peak expression, and rated each expression's intensity and appropriateness. Left/left and right/right composite images were constructed and compared for muscular activity by a second group of raters. Subjects also completed a facial perception task developed by Levy et al on which control subjects have shown a marked left hemifield bias.;Left hemiface dominance for emotional expression was not seen in either group. Side of facial dominance was significantly and inversely correlated with handedness in patients but not controls. The expected left perceptual hemispace bias was observed in significantly more controls (90%) than patients (63%). According to both objective and subjective measures, depressed subjects showed significant deficits in posing facial expressions of happiness and pleasant surprise, although they were unimpaired on negative expressions. Their neutral expressions looked no more negative than those of the controls.;Methodological considerations in measuring facial asymmetry are discussed and possible explanations for the observed perceptual bias are critically evaluated. Productive impairments in facial expression among depressed subjects are discussed in light of a proposed model based on the James-Lange Theory of emotion as applied to pathological mood states.