Inferior Frontal Gyrus Activity Triggers Anterior Insula Response to Emotional Facial Expressions

The observation of movies of facial expressions of others has been shown to recruit similar areas involved in experiencing one's own emotions: the inferior frontal gyrus (IFG). the anterior insula and adjacent frontal operculum (IFO). The Causal link bet between activity in these 2 regions, associated with motor and emotional simulation, respectively, has remained unknown. Here using psychophysiological interaction and Granger Causality Modeling, we show that activity in the IFO is causally triggered by activity in the IFG. and that this effective connectivity is specific to the IFG. These findings shed new light oil the intricate relationship between motor and affective components of emotional empathy.