Influence of mental activity on the respiration regulation during qigong exercise

Ancient qigong literature described mental activity as 'fire', respiration-regulation as 'wind', and considered that the integrated 'fire' and 'wind' can produce a marvelous physiological action. The course of mind concentration on respiration regulation was called 'WU HUO PENG LIAN', the process of mental quiescence and smooth breath was called 'WEN
HUO MU YU'. They played a very important role in some processes of qigong exercise.

Physiological information can be derived from the instantaneous heart rate. which depends upon the interaction between the pacemaker properties of cardiac tissue and autonomic nervous system activity. Sophisticated analysis of R-R interval variability by the power spectrum method reveals that there are two major components: a high frequency component
of around 0.3 Hz, corresponding to respiratory sinus arrhythmia, and a low frequency component of around 0.1 Hz, which is called Mayer wave and reflects the spontaneous oscillations of the cardiovascular system. Recent studies in this field showed that the two spectrum peaks of low and high frequencies are mediated separately by sympathetic and vagal activities. Thus, the ratio of low- to high-frequency could be a marker for assessing the change of sympatho-vagal balance. In addition, these spectrum peaks could affect each other in a certain condition, and forms the phenomenon as the 'entrainment of frequency' described in the
physics term.

In this study, the relation between the mental activity and respiration regulation was observed by using spectrum analysis for R-R interval variability on 60 volunteers. The results showed while respiratory frequency was regulated lower down towards the cardiac oscillatory frequency, the amplitude of the respiratory spectrum peak increased significantly, indicating the vagal activity to enhance. On the contrary, when the respiration regulation frequency increased, its amplitude decreased, and the ratio of low- to high-frequency increased, indicating the sympathetic activity excited. It reveals that the change of respiratory frequency controlled actively by the mental activity could alter the ratio of the low- to high-frequency, reflecting the direction of autonomic nervous balance. However, when the mental activity was quiescent and the respiration regulation was passive, the natural oscillation of cardiovascular system increased, both the respiration regulation frequency and its amplitude decreased. The spectrum peak of respiration regulation keeps to the natural oscillation of the cardiovascular system by reaching the psychosomatic tranquil state. At last. the two spectrum components combined to an united peak around 0.1 Hz, which indicates the sympatho-vagal balance came into a special state.

In conclusion, it can be verified by using the method of current experimental physiology for the relation between the mental activity and respiration regulation describe in ancient qigong literature.