Right-sided human prefrontal brain activation during acquisition of conditioned fear.
This H2(15)O positron emission tomography (PET) study reports on relative regional cerebral blood flow (rCBF) alterations during fear conditioning in humans. In the PET scanner, subjects viewed a TV screen with either visual white noise or snake videotapes displayed alone, then with electric shocks, followed by final presentations of white noise and snakes. Autonomic nervous system responses confirmed fear conditioning only to snakes. To reveal neural activation during acquisition, while equating sensory stimulation, scans during snakes with shocks and white noise alone were contrasted against white noise with shocks and snakes alone. During acquisition, rCBF increased in the right medial frontal gyrus, supporting a role for the prefrontal cortex in fear conditioning to unmasked evolutionary fear-relevant stimuli.
Fischer
Håkan
H
Aging Research Center, Karolinska Institute, Stockholm University, Sweden. hakan.fischer@neurotec.ki.se
Andersson
Jesper L R
JL
Furmark
Tomas
T
Wik
Gustav
G
Fredrikson
Mats
M
D000328:Adult; D000818:Animals; D001143:Arousal / Q000502:physiology; D005075:Biological Evolution; D001931:Brain Mapping; D003214:Conditioning, Classical / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D005260:Female; D006801:Humans; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D012911:Snakes; D014055:Tomography, Emission-Computed