Session S82.6

Heart Rate Variability Associated with Experienced Zen Meditation

M Hoshiyama*, A Hoshiyama

The University of Tokyo
Tokyo, Japan

Zen is a traditional meditation method which utilizes unification of body and mind. Though Zen has been sophisticated highly in Japan, it is spreading widely into western world today, realizing deeper meditation with less effort. While electroencephalogram (EEG) during Zen meditation has been studied in the past, there remains a lack of consensus whether heart rate during Zen practice elicit consistent heart rate variability (HRV) features especially for experienced and practicing Zen meditator.
To better understand the control of hemodynamic events elicited by deep Zen meditation during Zazen, we studied heart rate in 5 experienced Zen meditators and 5 beginners. The study took place over 4 sets of Zen meditations in a quiet, Zen practice hall in Kamakura or Tokyo. Each set of Zazen lasted for 25 minutes which was preceded by specific respiratory exercise. The first sets were used for habituation, and the data obtained from the following three sets were used for analysis.
Population averaged results for heart rate were not significantly different between experienced and beginners. Power spectrum analysis showed distinctive change in frequency components. Low and high frequency components increased for experienced mediators (p=0.05). Most notably, detrended fluctuations analysis (DFA) of HRV were around 1/2 for experienced meditators and 0.78 for beginners.
During Zen practice, we seat ourselves in a lotus posture, practice Tanden respiration, i.e., lower abdominal breathing, and keep mind free from specific state of consciousness. We attribute the increase in low and high frequency components to the response of autonomic arousal mechanism. In the previous sleep studies, DFA exponent of HRV decreased from 0.8 to around 1/2 when they fall into light sleep from awake. We attribute the decrease of DFA exponent in experienced meditators to the effective regulation of mind during meditation toward the edge of sleep, but not quite over it. This result suggests the possibility of HRV as a handy and quantitative evaluator for Zen meditation.

(Abstract Control Number: 177)