Fine-scale dynamics of functional connectivity in the face processing network during movie watching

Abstract

Face are naturally dynamic, multimodal and embedded in rich social context. However, mapping the face processing network in the human brain and its relation to behavior is typically done during rest or using isolated, static face images. The use of such contrived stimuli might result in overlooking widespread cortical interactions obtained in response to naturalistic context and the temporal dynamics of these interactions. Here we examined large-scale cortical connectivity patterns measured in response to a dynamic movie in a sample of typical adults (n=517), to determine how inter-subject functional connectivity (ISFC) relates to face recognition scores. We found a positive correlation with recognition scores in edges connecting the occipital visual and anterior temporal regions and a negative correlation in edges connecting attentional dorsal, frontal default, and occipital visual regions. These ISFC patterns resembled previous findings comparing individuals with congenital prosopagnosia to normal controls and the viewing of inverted compared to upright faces. To further examine these connectivity patterns, we developed a novel method that allows analysis of inter-subject stimulus-evoked node/edge responses at a single TR resolution. Using this method, we demonstrated that co-fluctuations in face-selective edges observed here and in previous work are related to local activity in core face-selective regions. Finally, correlating this temporal decomposition of the observed ISFC patterns to the movie content revealed that they peak during boundaries between movie segments rather than during the presence of faces in the movie. Our novel approach demonstrates how visual processing of faces is linked to fine-scale dynamics in attentional, memory, and perceptual neural circuitry.