In a previous functional magnetic resonance imaging
(fMRI) study of healthy subjects, we used simultaneous recording
of skin conductance responses to examine the differentiation
of limbic-prefrontal systems by autonomic
arousal (14). Amygdala and medial prefrontal activity was
associated specifically with fear stimuli that evoked a phasic
skin conductance arousal response. This pattern of activity
may represent a “visceral” system subserving the
subjective appraisal of threat (15–19). By contrast, distinct
hippocampus lateral prefrontal activity was elicited by
stimuli that did not evoke arousal responses and may represent
a “context” system for integrating the declarative
context of emotionally significant stimuli (16, 19, 20). To
date, schizophrenia deficits in the engagement of these
limbic-prefrontal circuits have not been examined in relation
to autonomic arousal.