Asymmetric intermittency observed in human heart rate dynamics

To gain a deeper understanding of intermittent fluctuations observed in complex, real-world systems, we propose positive- or negative-directional non-Gaussian statistics. As a numerical example of asymmetric intermittent fluctuations, we heuristically introduce a random cascade-type model. Using our method, it is demonstrated that the asymmetric properties of heart rate variability depend on aging. This provides new insight into the physiological mechanism controlling heart rate dynamics in health and in autonomic disorder.