Inter-subject synchronization of brain responses during movie watching

Abstract

The effect of shared exposure to naturalistic stimuli on the synchronization of brain activity has been investigated in previous literature. Increased synchronization has been found in several brain regions with exposure to the same movie. The parahippocampal place area (PPA) is known to respond particularly to places and scenes. This study focuses on this brain area and examines whether subjects build up more shared representations of recurring location motives in the PPA when they watch the same movie. To quantify the degree to which subjects create a shared representation, we analyze the progression of inter-subject correlation of brain activity in the PPA for the duration of the movie. We show that repeated exposure to movie locations increases synchronization between subjects during these specific locations, while overall synchronization stays relatively consistent during the whole movie.