Role of right pregenual anterior cingulate cortex in self-conscious emotional reactivity.

Self-conscious emotions such as embarrassment arise when one's actions fail to meet salient social expectations and are accompanied by marked physiological and behavioral activation. We investigated the neural correlates of self-conscious emotional reactivity in 27 patients with behavioral variant frontotemporal dementia (bvFTD), a neurodegenerative disease that disrupts self-conscious emotion and targets brain regions critical for emotional functioning early in the disease course, and in 33 healthy older controls. Subjects participated in an embarrassing karaoke task in which they watched a video clip of themselves singing. They also watched a sad film clip; these data were used to control for non-self-conscious emotional reactivity in response to audiovisual stimuli. Using Freesurfer to quantify regional brain volumes from structural magnetic resonance imaging, right pregenual anterior cingulate cortex (pACC) gray matter volume was the only brain region that was a significant predictor of self-conscious emotion. Smaller pACC volume was associated with attenuated physiological and behavioral self-conscious emotional reactivity, and this relationship was not specific to diagnosis. We argue that these results reflect the significant role that right pACC plays in the visceromotor responding that accompanies self-conscious emotion and that neurodegeneration in this region may underlie the self-conscious emotional decline seen in bvFTD.