The amygdala and appraisal processes: stimulus and response complexity as an organizing factor.
Brain Research Reviews. 2004-03-01; 44(2-3): 179-186
DOI: 10.1016/j.brainresrev.2003.08.008
Lire sur PubMed
The amygdala has been implicated in a variety of functions, ranging from
attention to memory to emotion. In theories about the amygdala’s role in
conditioned fear, the lateral amygdala (LA) is the primary, perhaps unique,
interface for incoming conditioned sensory stimuli and the central nucleus is the
major output station. Recent studies indicate, however, that amygdala output
pathways may be dissociated as a function of the type of conditioned fear
behavior. Based on behavioral, electrophysiological and anatomical evidence, the
present discussion proposes a modification of the traditional model of input
pathways to the amygdala such that the LA activation as a sensory interface is
limited to relatively simple, unimodal conditioned stimulus features whereas the
basal amygdaloid nucleus (B) may serve as an amygdaloid sensory interface for
complex, configural conditioned stimulus information. We further argue that the
partition of amygdalar nuclei according to a complexity dimension appears to
correspond both for input and output pathways and thus constitutes a common
organizing factor in the functional anatomy of the amygdala. The extensive
intra-amygdala wiring is assumed to underlie the computations necessary to
perform behavioral decisions of various levels of complexity. Collectively, these
results endow the amygdala with a more sophisticated role in guiding motivation
and behavior.