Dynamic fluctuations in ascending heart–to–brain communication under mental stress

Abstract

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.