Affective representations and brain-body dynamics during emotional video viewing

Emotional events evoke changing neural and bodily responses, but how these responses relate to overall emotional evaluations and how brain and body responses correspond over time remain unclear. Ninety-two participants viewed 25 silent emotional videos, each approximately one minute long, and rated valence and arousal after each video. We recorded brain activity using magnetoencephalography alongside cardiac, electrodermal, respiratory and facial-muscle activity. Representational similarity analysis (RSA) compared source-resolved cortical spectral patterns and peripheral response patterns with participants' valence and arousal ratings, adjusting each affective dimension for the other. Across whole videos, valence similarity corresponded to beta-band power patterns predominantly in left sensorimotor and frontotemporal cortex and to facial-muscle responses. Arousal similarity corresponded to alpha-band power patterns in the right frontoparietal cortex and to phasic electrodermal activity. The neural associations persisted after adjustment for visual and semantic similarities between the videos. Windowed neural correspondence with retrospective valence was significant from around 10 s onwards, with both neural and facial-muscle associations strengthening towards the end of the videos, whereas no significant windowed arousal associations were detected throughout viewing. We further applied dynamic RSA to compare neural and physiological response patterns across videos at different temporal lags. Correspondence exceeded a temporally decoupled reference for facial muscles, heart rate and electrodermal activity, but not respiration rate. On average, corrugator activity preceded corresponding neural patterns by about 1 s, zygomaticus activity occurred at approximately the same time, and heart-rate and electrodermal activity followed about 1.7 s and 4.5 s later, respectively. Together, these findings link overall affective evaluations to complementary neural and peripheral response geometries and reveal signal-specific temporal profiles of ongoing brain-body correspondence.