Hemispheric perception of emotional valence from facial expressions.

Abstract

The authors previously reported that normal subjects are better at discriminating happy from neutral faces when the happy face is located to the viewer's right of the neutral face; conversely, discrimination of sad from neutral faces is better when the sad face is shown to the left, supporting a role for the left hemisphere in processing positive valence and for the right hemisphere in processing negative valence. Here, the authors extend this same task to subjects with unilateral cerebral damage (31 right, 28 left). Subjects with right damage performed worse when discriminating sad faces shown on the left, consistent with the prior findings. However, subjects with either left or right damage actually performed superior to normal controls when discriminating happy faces shown on the left. The authors suggest that perception of negative valence relies preferentially on the right hemisphere, whereas perception of positive valence relies on both left and right hemispheres.

Abnormal temporal and prefrontal cortical gray matter thinning in psychopaths

“…The finding of right hemisphere pathology in psychopaths is consistent with observations from lesion studies, showing that damage to the right hemisphere impairs the ability for effective recognition, especially for negative facial expression, 6,7 similar to dysfunctions documented in psychopaths. 1 Our findings of cortical thinning within frontal and temporal regions are also in agreement with earlier studies that show frontal and temporal gray matter volume reductions in psychopathic individuals, 5,8 and support earlier hypotheses that both regions and/or associated disturbances of fronto-temporal circuitry play an important role in the underlying neuropathology of psychopathy. Damage to the dorsolateral and ventromedial prefrontal cortices has been shown to disrupt normal decision making, 9 although damage to the medial temporal cortex critically impairs processing for the emotional and social context of information.…”

Models of hemispheric specialization in facial emotion perception—a reevaluation.

“…There has been considerable evidence supporting the idea that the left and the right hemispheres are differentially involved in the perception of emotions (Adolphs, Jansari, & Tranel, 2001; Ahern & Schwartz, 1979;Harmon-Jones, 2004;Wedding & Stalans, 1985), which is relatively consistent across different cultures (Eviatar, 1997).…”

“…However, far from been unanimous, studies on FCAs for facial emotion perception have led to three partly conflicting models: (i) the Right Hemisphere Hypothesis (Borod et al, 1998), (ii) the Valence-Specific Hypothesis (Adolphs et al, 2001;Ahern & Schwartz, 1979;Wedding & Stalans, 1985), and (iii) the Approach/Withdrawal model (Harmon-Jones, 2004). The first hypothesis posits that all emotions are preferentially processed by the right hemisphere.…”

Decreased Volume of the Brain Reward System in Alcoholism

“…Processing of emotions engages differentially the two hemispheres, with negative emotional processing predominantly in right hemisphere and positive emotional processing primarily in the left hemisphere (35,95,96). In the present report, the localization of right dorsolateralprefrontal cortex, right anterior insula, and right NAc deficits supports the right hemisphere and frontal hypotheses of deficits in alcoholism (16,35).…”