IMPAIRED AUDITORY RECOGNITION OF FEAR AND ANGER FOLLOWING BILATERAL AMYGDALA LESIONS

The amygdalar complex is a medial temporal lobe structure in the brain which is widely considered to be involved in the neural substrates of emotion, Selective bilateral damage to the human amygdala is rare, of fering a unique insight into its functions. There is impairment of soc ial perception after amygdala damage, with defective recognition of fa cial expressions of emotion(1-4). Among the basic emotions, the proces sing of fear and anger has been shown to be disrupted by amygdala dama ge(1,2,5). Although it remains puzzling why this not found in all case s(6), the importance of the amygdala in negative emotion, and especial ly fear, has been confirmed by conditioning(7), memory(8) and positron emission tomography (PET) experiments(9,10). Central to our understan ding of these findings is the question of whether the amygdala is invo lved specifically in the perception of visual signals of emotion emana ting from the face, or more widely in the perception of emotion in all sensory modalities(11). We report here a further investigation of one of these rare cases, a woman (D.R) who has impaired perception of the intonation patterns that are essential to the perception of vocal aff ect, despite normal hearing, As is the case for recognition of facial expressions, it is recognition of fear and anger that is most severely affected in the auditory domain, This shows that the amygdala's role in the recognition of certain emotions is not confined to vision, whic h is consistent with its being involved in the appraisal of danger and the emotion of fear(12,13).