The role of inferior frontal gyrus in emotion regulation: Evidence from fMRI and tDCS investigation.

Previous neuroimaging studies indicate that the inferior frontal gyrus (IFG) may be associated with emotion regulation through the use of cognitive reappraisal strategy. However, whether there is a causal role of IFG in reappraisal-based regulation of general negative emotions remains unclear. Therefore, the present study employed a two-study, progressive research framework combining functional magnetic resonance imaging (fMRI) and transcranial direct current stimulation (tDCS) to investigate the critical role of the IFG in reappraisal-based emotion regulation. In Study 1 (fMRI experiment), thirty-two participants completed an emotion regulation task during scanning. Brain activations were compared between reappraisal condition and view condition to identify neural correlates of emotion regulation. Whole-brain family-wise error (FWE p < 0.05) correction revealed significant activation in the bilateral IFG and other frontal-temporal regions during the use of reappraisal strategy. In Study 2 (tDCS experiment), building on the fMRI findings, twenty participants were recruited to complete the emotion regulation task while receiving counterbalanced active or sham anodal tDCS over the right IFG (one week apart), to observe potential changes in regulation effect when using the reappraisal strategy. Results showed that active tDCS significantly enhanced the regulation effect of reappraisal compared to sham stimulation. Collectively, these findings provide converging evidence for a critical role of the right IFG in reappraisal-based down-regulation of general negative emotions. This may have potential implications for clinical interventions, particularly in psychiatric conditions associated with emotion regulation deficits.