Simulating Emotional Responses in Posttraumatic Stress Disorder: An fMRI Study
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This study tested the extent to which coached participants can simulate the neural responses of participants with posttraumatic stress disorder (PTSD) when they are presented with signals of fear. Functional magnetic resonance imaging (fMRI) was used to study blood oxygenation level-dependent signal during the presentations of fearful and neutral faces under both conscious and nonconscious (masked) conditions. Participants comprised 12 patients with PTSD and 12 trauma-exposed controls who were instructed to simulate PTSD. During conscious fear processing, simulators showed greater activation in the left amygdala and medial prefrontal cortex (MPFC) than PTSD participants. By contrast, during nonconscious processing, PTSD participants had greater MPFC activation than simulators. These findings suggest that coached simulators produce a profile of ‘over-responding’ to fear when controlled conscious processing is possible, but are not able to simulate the exaggerated medial prefrontal responses observed in PTSD participants under conditions of nonconscious processing.
KeywordsFear Neural networks Posttraumatic stress disorder Simulation
This study was funded by an ARC Linkage Grant (LP0212048) and a NHMRC Program Grant (300403). We acknowledge the collaboration with the Brain Resource International Database (BRID) in recruitment and testing of participants.
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