2022 Volume 40 Issue 1 Pages 68-92
Heart rate variability (HRV) has been widely used in psychophysiology and related areas to investigate the activity of the autonomic nervous system. This article describes psychophysiological evaluation using HRV analysis and the clinical applications of HRV enhancement (HRV biofeedback). The high-frequency component of HRV (respiratory sinus arrhythmia: RSA) is a reliable cardiac vagal activity index under controlled conditions. Moreover, RSA can evaluate psychophysiological responsivity to various behavioral tasks (e.g., stress and relaxation). In contrast, the nature of cardiac vagal modulation suggests that RSA is an endogenous marker of cardiopulmonary resting function rather than an index of cardiac vagal activity. Furthermore, RSA might be able to evaluate daily life psychophysiological states. This article also describes the origin of HRV biofeedback in the clinical application of HRV enhancement, its clinical usefulness, and the mechanisms underlying the biofeedback techniques’ efficacy. Baroreceptor reflex, which plays an essential role in regulating the cardiovascular system, has resonance characteristics and respiratory control at the resonance frequency (approximately 0.1 Hz) produces a large increase in HRV. HRV biofeedback improves autonomic homeostatic functions in baroreceptor reflexes through the resonance effect, ameliorates various stress symptoms, and regulates emotions. Finally, this article proposes that HRV analysis could be a valuable tool for assessing multiple psychophysiological conditions. Moreover, HRV enhancement could be an essential factor for maintaining mental and physical health and well-being.
