Lateralization of Facial Emotional Expression in Schizophrenic and Depressed Patients

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.

Temporal Dynamics of Neural Processing of Facial Expressions and Emotions

“…Further, in sharp contrast to the findings of earlier behavioral studies (Mandal et al, 2001;Bhushan, 2006) supporting hemifacial bias, which found the left side of the face to distinctly express negative emotions, our findings suggest that the right side of the face provides distinct information for perception of emotion, while activation is increased in the right hemisphere during this process. These findings both agree and disagree with the right-hemisphere hypothesis -support for which has found the right hemisphere is dominant for negative emotions whereas the left hemisphere is dominant for positive emotions (Silberman and Weingartner, 1986;Heilman and Bowers, 1990;Yecker et al, 1999). The current findings relating to hemispheric dominance are better aligned with previous research on the perception of emotion, which has also evidenced right hemisphere dominance irrespective of emotional valence (Bryden M. P., 1982;Davidson, 1984).…”

Human (Homo sapiens) and baboon (Papio papio) chimeric face processing: Right-hemisphere involvement.

“…left-sided asymmetric preference (e.g., Yecker et al, 1999). A left-half preference has also been found for chimpanzees' neutral faces in a chimeric task (Fernández-Carriba et al, 2002a, 2002b, 2004.…”

Changes in Posed Facial Expression of Emotion Across the Adult Life Span

“…Raters were oriented to facial cues that define intensity, including tightness of the skin around the eyes and mouth, depth of the nasolabial fold, and drawing up of the cheeks and eyebrows. Written descriptions of these facial cues were provided to the raters as adapted from Borod et al (1983, Canino, Borod, Madigan, Tabert, and Schmidt (1999), Jaeger et al (1986), Kent et al (1988), andYecker et al (1999). These written materials were supplemented with photographs displaying three different intensity levels of a happiness expression, as presented by Ekman and Friesen (1975, Chapter 8) and as reproduced by to represent low, moderate, and extreme levels of expression intensity.…”

“…Research has shown that individuals with depression have deficits in the expression of facial emotion (Berenbaum, 1992;Jaeger et al, 1986;Leven, Knight, Hall, & Alpert, 1985;Yecker et al, 1999). The three poser age groups were carefully screened for normal range performance on the Self-Rating Depression Scale (Zung, 1965).…”