ABSTRACT
This study examined facial emotional expressions produced by schizophrenic (SZ), unipolar depressed (UD), and normal control (NC) righthanded adults. Hypotheses regarding right-hemisphere activation in UD and suppression in SZ were addressed, as well as hypotheses about emotion and laterality. Subjects were videotaped while posing positive, neutral, and negative facial expressions to verbal command and to visual imitation. Naive judges rated hemiface stimuli for intensity in original and mirror-reversed orientations. Overall, SZs produced expressions with diminished intensity relative to UDs and NCs. Across subject groups, expressions were more intense in the visual than the verbal condition. In general, approach expressions were produced with greater right-hemiface intensity, and withdrawal expressions with greater left-hemiface intensity. UDs showed more pronounced facial asymmetry than SZs or NCs. An unanticipated right-hemispace perceptual bias among the judges may reflect the analytical, detailed rating procedure used and the presumably greater reliance by the judges on left-than right-hemisphere strategies.
Subject(s)
Affect/physiology , Brain/physiopathology , Depressive Disorder/psychology , Facial Expression , Functional Laterality/physiology , Schizophrenia/diagnosis , Schizophrenia/physiopathology , Visual Perception/physiology , Adult , Demography , Female , Humans , Interview, Psychological , Male , Psychological Tests , Schizophrenic Psychology , Severity of Illness Index , Video Recording , Visual Fields/physiologyABSTRACT
The purpose of the current study was to examine 49 extant experiments of facial asymmetry during emotional expression in normal adult males and females in regard to gender, valence, and measurement technique. When facial asymmetry was evaluated by trained judges or muscle quantification, facial expressions were left-sided, a finding implicating the right cerebral hemisphere in emotional expression. However, when self-report experiential methods were utilized, the valence hypothesis received some support. Although there was some indication in single-gender studies of greater facial lateralization for males than for females, studies involving both males and females yielded no systematic asymmetry patterns as a function of gender.
