A SPECIFIC NEURAL SUBSTRATE FOR PERCEIVING FACIAL EXPRESSIONS OF DISGUST

Recognition of facial expressions is critical to our appreciation of t he social and physical environment, with separate emotions having dist inct facial expressions'. Perception of fearful facial expressions has been extensively studied, appearing to depend upon the amygdala(2-6). Disgust-literally 'bad taste'-is another important emotion, with a di stinct evolutionary history(7), and is conveyed by a characteristic fa cial expression(8-10). We have used functional magnetic resonance imag ing (MRI) to examine the neural substrate for perceiving disgust expre ssions. Normal volunteers were presented with faces showing mild or st rong disgust or fear. Cerebral activation in response to these stimuli was contrasted with that for neutral faces. Results for fear generall y confirmed previous positron emission tomography findings of amygdala involvement. Both strong and mild expressions of disgust activated an terior insular cortex but not the amygdala; strong disgust also activa ted structures linked to a limbic cortico-striatal-thalamic circuit. T he anterior insula is known to be involved in responses to offensive t astes. The neural response to facial expressions of disgust in others is thus closely related to appraisal of distasteful stimuli.