Heart-brain coupling and its relevance for individual trait characteristics

A bulk of recent neurophysiological research has focused on how bodily functions are intertwined with neural activity, but the dynamic heart-brain coupling and its relevance for individual trait characteristics remains largely unexamined. Thus, our aim was to investigate how ongoing oscillatory brain activity is modulated by the natural fluctuations in heart rate variability (HRV). We further explored whether heart-brain coupling is associated with individual trait characteristics. Magnetoencephalography (MEG) together with electrocardiography (ECG) were used to record neural activity and HRV during rest. Self-reported trait characteristics were examined using Behavioral Inhibition and Activation Systems Scale (BIS/BAS) and attunement to internal bodily sensations using Body Vigilance Scale (BVS). Statistically significant increases were observed for low HRV vs. high HRV state in alpha and beta power (p < 0.05) indicating that oscillatory brain activity is modulated by fluctuations in HRV. Moreover, we demonstrated that heart-brain coupling was associated with self-reported behavioral approach and avoidance tendencies. The results of the moderator analysis further indicated that the relationship between heart-brain coupling and trait characteristics is at least partly moderated by the attunement to internal bodily sensations. Our findings bring insights to the intricate interplay between cardiac and neural signaling and its relationship with individual trait characteristics. ### Competing Interest Statement The authors have declared no competing interest.