Cardiac sympathovagal activity initiates a functional brain-body response to emotional processing

Abstract A century-long debate on bodily states and emotions persists. While the involvement of bodily activity in emotion physiology is widely recognized, the specificity and causal role of such activity related to brain dynamics has not yet been demonstrated. We hypothesize that the peripheral neural monitoring and control of cardiovascular activity prompts and sustains brain dynamics during an emotional experience, so these afferent inputs are processed by the brain by triggering a concurrent efferent information transfer to the body. To this end, we investigated the functional brain-heart interplay under emotion elicitation in publicly available data from 62 healthy participants using a computational model based on synthetic data generation of EEG and ECG signals. Our findings show that sympathovagal activity plays a leading and causal role in initiating the emotional response, in which ascending modulations from vagal activity precede neural dynamics and correlate to the reported level of arousal. The subsequent dynamic interplay observed between the central and autonomic nervous systems sustains emotional processing. These findings should be particularly revealing for the psychophysiology and neuroscience of emotions. Significance We investigate the temporal dynamics of brain and cardiac activities in healthy subjects who underwent an emotional elicitation through videos. We demonstrate that, within the first few seconds, emotional stimuli modulate the heart activity, which in turn stimulate an emotion-specific cortical response in the brain. Then, the conscious emotional experience is sustained by a bidirectional brain-heart interplay and information exchange. Moreover, the perceived intensity of an emotional stimulus is predicted by the intensity of neural control regulating the heart activity. These findings may constitute the fundamental knowledge linking neurophysiology and psychiatric disorders, including the link between depressive symptoms and cardiovascular disorders.