N2 event-related potential component is associated with cardiac autonomic tone regulation during mental fatigue.

Mental fatigue alters cognitive performance and autonomic regulation. The neurovisceral model proposes that forebrain structures associated to cognitive control abilities influences heart rate variability. Parasympathetic mediated heart rate variability indices reduction during mental fatigue experience is well-described in previous studies, but the contribution of heart-brain axis to cardiac autonomic adaptation remains unknown. This study investigates the association between root mean square of successive differences between RR intervals (rMSSD) and N2 event-related potential component during visual prolonged odd/ball task (≅ 60min.). The comparison between task blocks shows that rMSSD (p = 0.004) and N2 (p = 0.04) decreased with time on task. Pearson correlation shows that ΔrMSSD is associated with ΔN2 (p = 0.007). Our results support the neurovisceral integration model showing that cognitive control contributes to cardiac autonomic tone adaptation during mental fatigue experience.