Heart-brain interplay during a prolonged vigilance task is improved by prior autonomous resonance practice

The physiology of heart-brain interplay has been described as an interconnected network spreading from (sub)cortical areas to cardiac autonomous control. Coordinated activities emerge in this network as substrates for both top-down and bottom-up activities, linking heart rate variability (HRV) to cerebral functions. As a main facet of such functioning, leading the autonomous modulation of HRV toward the specific 0.1Hz resonance frequency, which is achievable by breathing at 0.1Hz, has been shown to improve parasympathetic bottom-up activation, with obvious benefits for mental activity. So, guided breathing has become a reliable practice to stimulate (sub)cortical structures aiming at gaining mental health, reducing stress, and improving overall well-being. Less is known on potential gains regarding cognitive functions and how they could be better maintained during prolonged cognitive activity, with possible correlates in HRV. Here we aimed to show the effect of a unique sequence of cardiac resonance with coupled HRV biofeedback (to optimize heart-to-brain bottom-up) on HRV correlates of sustaining cognitive performance during a prolonged vigilance test (PVT). Sixty-nine physically active students (20 ± 2 years) performed a 20-min PVT consisting of visually tracking boats over the sea line on a computer screen. Cognitive performance was characterized by reaction times (RT) to blue boat apparition and false inhibition when red boats appeared (% false hits). An experimental group (36 participants) practice prior cardiac coherence (5-min) guided by haptic and visual biofeedback (a returned information to strictly follow their 0.1Hz heart rhythm); a sample of 33 participants served as control group. Main indices of HRV were obtained all along the task as well as before and after the PVT tasks from RR intervals. As main results, the cognitive performance (RT) was better maintained during PVT in the experimental group. The cognitive load reached similar self-reported (NASA-TLX) levels. Visual and analogic scale scoring indicated that fatigue and stress grew up in both groups but were less pronounced after cardiac coherence. All HRV markers failed to show group singularities when assessed before vs. after the task. Yet, when assessed during the task, the experimental group maintained much higher RMSSD (and HF-power) parasympathetic levels along time despite unchanged total autonomous power. In this group, the level of multiscale entropy in HRV dynamics (assessed by RCMSE) was maintained whereas it dropped in the control group. As further analysis, a hierarchical clustering analysis on the principal components allowed to distinguish three clusters among the participants in the experimental group, opening a new window on grasping the main individual roots for improving cognitive functioning with parasympathetic stimulation for vigilance tasks. This research was funded by the Association Nationale de la Recherche et de la Technologie (ANRT) to URGOTECH FRANCE, in support of the work of Pierre Bouny, PhD student This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.