Parallel incentive processing: an integrated view of amygdala function

Balleine, B.W. & Killcross, S. (May 2006). Parallel incentive processing: an integrated view of amygdala function. Trends in Neuroscience, Vol. 29, 272-279.

Although the amygdala has been long studied for its involvement in emotional learning and memory, the exact nature of its involvement is still disputed. Historically, a serial model has predominated, with the lateral nucleus detecting threatening stimuli and the central nucleus initiating expression of defensive behaviors and other bodily responses associated with fear reactivity. However, in this paper Balleine and Killcross opine perhaps it's time to consider alternative models, and propose a model which, based on appetitive conditioning studies, has the basolateral and central nuclei operating independently and in parallel to mediate incentive processes in both appetitive and aversive situations. They suggest the basolateral nucleus encodes emotional events with reference to their particular sensory features, while the central nucleus provides affective significance to processing, motivating or inciting responses and actions.