Physiological responses to aversive and non-aversive audiovisual, auditory, and visual stimuli

We examined differences in physiological responses to aversive and non-aversive naturalistic audiovisual stimuli and their auditory and visual components within the same experiment. We recorded five physiological measures that have been shown to be sensitive to affect: electrocardiogram, electromyography (EMG) for zygomaticus major and corrugator supercilii muscles, electrodermal activity (EDA), and skin temperature. Valence and arousal ratings confirmed that aversive stimuli were more negative in valence and higher in arousal than non-aversive stimuli. Valence also showed an emotional enhancement effect for cross-modal integration. Both heart rate deceleration and facial EMG potentiation for corrugator supercilii were larger for aversive compared to non-aversive conditions for audiovisual stimuli and their auditory components, even after controlling for arousal. Facial EMG potentiation for zygomaticus major was greater for aversive compared to non-aversive conditions for audiovisual stimuli and EDA was greater for aversive compared to non-aversive conditions for visual stimuli. Neither of these effects remained significant after controlling for arousal. These findings provide a benchmark for examining atypical sensory processing of mundane aversive stimuli for clinical populations.