Neocortical modulation of the amygdala response to fearful stimuli.
BACKGROUND
The cortical circuitry involved in conscious cognitive processes and the subcortical circuitry involved in fear responses have been extensively studied with neuroimaging, but their interactions remain largely unexplored. A recent functional magnetic resonance imaging (fMRI) study demonstrated that the engagement of the right prefrontal cortex during the cognitive evaluation of angry and fearful facial expressions is associated with an attenuation of the response of the amygdala to these same stimuli, providing evidence for a functional neural network for emotional regulation.


METHODS
In the current study, we have explored the generalizability of this functional network by using threatening and fearful non-face stimuli derived from the International Affective Picture System (IAPS), as well as the influence of this network on peripheral autonomic responses.


RESULTS
Similar to the earlier findings with facial expressions, blood oxygen level dependent fMRI revealed that whereas perceptual processing of IAPS stimuli was associated with a bilateral amygdala response, cognitive evaluation of these same stimuli was associated with attenuation of this amygdala response and a correlated increase in response of the right prefrontal cortex and the anterior cingulate cortex. Moreover, this pattern was reflected in changes in skin conductance.


CONCLUSIONS
The current results further implicate the importance of neocortical regions, including the prefrontal and anterior cingulate cortices, in regulating emotional responses mediated by the amygdala through conscious evaluation and appraisal.
Hariri
Ahmad R
AR
Clinical Brain Disorders Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, USA.
Mattay
Venkata S
VS
Tessitore
Alessandro
A
Fera
Francesco
F
Weinberger
Daniel R
DR
D000328:Adult; D000339:Affect; D000679:Amygdala / Q000033:anatomy & histology* / Q000378:metabolism*; D003071:Cognition / Q000502:physiology; D004867:Equipment Design; D005239:Fear; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D008297:Male; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000033:anatomy & histology* / Q000378:metabolism*
D010100:Oxygen