There is increasing evidence that brain structures involved in the experience of particular emotions may also be involved in recognizing those emotions in others. In the November 2000 issue of Nature Neuroscience (Vol. 3, No. 11, pp. 1077-1078), Andrew Calder and colleagues (Cambridge) report on a patient with a brain lesion that selectively interferes with his ability to identify facial and vocal expressions indicating disgust in other people. The patient's brain damage includes the insula and putamen, regions that are activated by viewing faces with disgusted expressions in normal subjects. (The insula is also activated by unpleasant tastes, which is interesting as disgust is proposed to have evolved as a response to offensive foods.) The patient had no difficulty identifying happiness, fear, anger, sadness or surprise in facial expressions or in nonverbal sounds (laughter for happiness, and so forth). Although he understands the concept of disgust at an intellectual level, and was able to identify disgusting visual scenes correctly, his emotional reaction to a variety of disgusting scenarios was impaired relative to that of normal subjects. In contrast, his reaction to other negative emotions such as anger and fear was normal. These results suggest that there is a specialized brain system involved in both recognition and experience of disgust across sensory modalities, and may explain why patients with Huntington's disease, which also damages the insula and putamen, have specific difficulty in recognizing disgust in others.
Dr. Andrew J. Calder
MRC Cognition & Brain Sciences Unit
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CB2 2EF Cambridge
tel: +44 1223 355 294, extension 741
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(C) Nature Neuroscience press release.
Message posted by: Trevor M. D'Souza