Brain–heart interplay modulation during biofeedback: A new frontier in understanding self-regulation

Introduction: The intricate communication between the brain and the inner body significantly impacts human behavior, with disruptions in this dialog potentially leading to decreased self-regulation and higher risk of depression, anxiety, and cognitive impairment. The present study tested Brain-Heart Interplay (BHI) indexes during a voluntary self-regulation task involving biofeedback of heart rate (HR-BF). Methods: Forty-five healthy students underwent a single session of HR-BF in which they were required to modulate their cardiac activity by increasing or decreasing HR relative to baseline, with or without visual feedback, while an electroencephalogram and electrocardiogram were co-registered to calculate BHI indexes. Results: Participants performed better at increasing versus decreasing HR (p .001), and in presence of feedback, in respect to absence of feedback (p = .005). During HR decrease, higher brain-to-HRV coupling in theta and alpha frequency bands emerged (p . 05). During HR increase, higher HRV-to-alpha coupling occurred (p.05). Finally, greater brain-to-HRV coupling was observed without feedback (p . 05). Conclusions: These findings highlight distinct patterns of brain-heart interaction during an attempt at voluntary self-regulation. Opposite patterns of BHI indexes emerged in increase vs. decrease HR, suggesting the presence of different mechanisms supporting the voluntary attempt at self-regulation. Moreover, the higher top-down control without feedback may suggest greater cognitive demand to modulate cardiac arousal. By elucidating the intricate relationships between neural activity and cardiac function during volitional self-regulation, this research opens new avenues for understanding the psychophysiological mechanisms and the role of brain-heart communication in conscious autonomic control.