The contribution of the amygdala to normal and abnormal emotional states.

Lesion studies in monkeys have provided some of the most compelling evidence for the involvement of the amygdala in emotional and social behaviour. In spite of this it has proved surprisingly difficult to uncover the precise nature of the role of the amygdala. A number of recent studies now indicate that the amygdala is involved in a specific class of stimulus-reward associations and this discovery, combined with important anatomical findings, has made it possible to gain a much more detailed appreciation of the contribution of the amygdala to emotion in non-human primates. In parallel with this, it appears increasingly likely that amygdala dysfunction contributes to the emotional changes that accompany certain neurological disorders, including dementia and schizophrenia.