Critchley HD, Mathias CJ, Dolan RJ.
Wellcome Department of Imaging Neuroscience, 12 Queen Square, Institute of Neurology
and Institute of Cognitive Neuroscience, UCL, WC1N 3BG, London, United Kingdom.
The degree to which perceptual awareness of threat stimuli and bodily states of arousal
modulates neural activity associated with fear conditioning is unknown. We used
functional magnetic neuroimaging (fMRI) to study healthy subjects and patients with
peripheral autonomic denervation to examine how the expression of conditioning-related activity is modulated by stimulus awareness and autonomic arousal. In controls,
enhanced amygdala activity was evident during conditioning to both "seen" (unmasked)
and "unseen" (backward masked) stimuli, whereas insula activity was modulated by
perceptual awareness of a threat stimulus. Absent peripheral autonomic arousal, in
patients with autonomic denervation, was associated with decreased conditioning-related activity in insula and amygdala. The findings indicate that the expression of
conditioning-related neural activity is modulated by both awareness and representations
of bodily states of autonomic arousal.
Neuron. 2002 Feb 14;33(4):653-63. Links