Dynamic fluctuations in ascending heart–to–brain modulations under mental stress elicitation

Previous endeavors have revealed how the dynamical information exchange between central and autonomous nervous systems, as measured from brain–heart interplay, can explain emotional arousal and physical stress. In this study, we test our recently proposed computational framework for a functional brain–heart interplay assessment; the Sympatho-Vagal Synthetic Data Generation Model. The model estimates the causal and bidirectional neural modulations between EEG oscillations and sympathetic/parasympathetic activity. Here, mental stress is elicited by increasing the cognitive demand and quantified on 37 human volunteers. The increase on mental stress induced an increased variability on heart–to–brain functional interplay, primarily from sympathetic activity on EEG oscillations in the delta and beta bands. Existing theoretical and experimental evidence has shown that stress involves top-down neural dynamics in the brain. Therefore, our results show that mental stress involves dynamic and bidirectional neural interactions at a brain–body level as well, where bodily feedback shapes the perceived stress caused by an increased cognitive demand. We conclude that brain–heart interplay estimators are suitable biomarkers for stress measurements. Highlights ### Competing Interest Statement The authors have declared no competing interest.