Consistency of affective responses to naturalistic stimuli across individuals using intersubject correlation analysis based on neuroimaging data

In this study, we utilized functional magnetic resonance imaging (fMRI) data obtained for naturalistic emotional stimuli to examine the consistency of neural responses among participants in specific regions related to valence. We reanalyzed fMRI data from 17 participants as they watched episodes of "Sherlock" and used emotional ratings from 125 participants. To determine regions where neural response patterns were synchronized across participants based on the pattern of valence changes, intersubject correlation analysis was conducted. As a validation analysis, multidimensional scaling was conducted to investigate emotional representation for significant regions of interest. The results revealed increased neural synchrony in the ventromedial prefrontal cortex, bilateral superior frontal cortex, left posterior cingulate cortex, thalamus, right anterior cingulate cortex, and bilateral inferior frontal cortices during the presentation of positive scenes. Also, the bilateral superior temporal gyrus and bilateral medial temporal gyrus exhibited increased neural synchrony as negative scenes were presented. Moreover, the left inferior frontal cortex and right superior frontal gyrus were found to be engaged in emotion representation and display increased neural synchrony. These findings provide insights into the differential neural responses to emotionally evocative naturalistic stimuli as compared to conventional experimental stimuli. Also, this study highlights the future potential for using intersubject correlation analysis for examining consistency of neural responses to naturalistic stimuli.