Prefrontal control of the amygdala during real-time fMRI neurofeedback training of emotion regulation

摘要

We observed in a previous study (PLoS ONE 6:e24522) that the self-regulationof amygdala activity via real-time fMRI neurofeedback (rtfMRI-nf) with positiveemotion induction was associated, in healthy participants, with an enhancementin the functional connectivity between the left amygdala (LA) and six regionsof the prefrontal cortex. These regions included the left rostral anteriorcingulate cortex (rACC), bilateral dorsomedial prefrontal cortex (DMPFC),bilateral superior frontal gyrus (SFG), and right medial frontopolar cortex(MFPC). Together with the LA, these six prefrontal regions thus formed thefunctional neuroanatomical network engaged during the rtfMRI-nf procedure. Herewe perform a structural vector autoregression (SVAR) analysis of the effectiveconnectivity for this network. The SVAR analysis demonstrates that the leftrACC plays an important role during the rtfMRI-nf training, modulating the LAand the other network regions. According to the analysis, the rtfMRI-nftraining leads to a significant enhancement in the time-lagged effect of theleft rACC on the LA. The training is also accompanied by significant increasesin the instantaneous (contemporaneous) effects of the left rACC on four otherregions - the bilateral DMPFC, the right MFPC, and the left SFG. Theinstantaneous effects of the LA on the bilateral DMPFC are also significantlyenhanced. Our results are consistent with a broad literature supporting therole of the rACC in emotion processing and regulation. Our analysis provides,for the first time, insights into the causal relationships within the networkof regions engaged during the rtfMRI-nf procedure targeting the amygdala. Itsuggests that the rACC may constitute a promising target for rtfMRI-nf trainingalong with the amygdala in patients with affective disorders, particularlyposttraumatic stress disorder (PTSD).