Heart activity, not brain activity, is what triggers an emotional response

30.05.2022

The University of Pisa, in collaboration with the University of Padua and the University of California Irvine, published the study Cardiac sympathetic-vagal activity initiates a functional brain-body response to emotional arousal in the journal Proceedings of the National Academy of Science of the USA. The study analyzed the mechanism that leads us to experience specific emotions in the face of certain stimuli, investigating the theory that the root of emotional response comes from the heart.

To prove this theory, researchers applied a computational model to electrocardiographic and electroencephalographic signals in healthy subjects while exposing them to videos with unpleasant or pleasant emotional content. They discovered that in the first few seconds, the stimulus modifies cardiac activity that induced and modulated a specific response of the cortex. A continuous and bidirectional exchange of information between heart and brain underlies the entire conscious experience of emotion and, above all, its intensity.

Gaetano Valenza, Bioengineering Professor at the Department of Information Engineering of the University of Pisa explains, “Obviously, the complexity of the emotions we feel come from the intricate exchange between our nervous system and various peripheral systems, but heart activity, not brain activity, is what triggers an emotional response."

To be able to extract the evaluation of an emotional state from a simple ECG analysis, the researchers developed mathematical equations capable of continuously decoding the heart-brain communication in the different emotional states. This means that in the future, under certain cardiac dynamics, it could be possible to understand the emotion a subject experienced under observation using a smartwatch.

Prof Claudio Gentili of the Department of General Psychology and Center for Clinical Psychological Services of the University of Padua notes, "This discovery could offer a significant impact on the understanding of mental disorders and their relationship with physical health. This may explain why those with affective disorders, such as depression also experience a greater probability of developing heart disease, or, vice versa, among subjects with heart problems such as coronary heart disease or arrhythmias there is an increase in anxiety and depression.