Qigong has a history of thousands of years in China. It is one of methods for prevention and treatment of diseases, and for health preservation.
With the development of the human science, the research of the qigong eigen state was more and more concerned.
Professor Qian Xuesen points out that the important task is to establish the theory of the qigong phenomena and the qigong state of the human body must be studied in detail with advanced techniques and correct guiding thoughts. Therefore, according to the principle of integration, interconnection, dynamics and orderization, the dynamical changes of multi physiological indicators in the qigong state were repeatedly observed to provide a scientific basis for research of physiological characters in the qigong state and for promoting the human body to enter optimal functional state.
In this paper, the changes of EEG in the qigong state was further investigated with the technique of power spectral matrix in time series on observed multi-physiological indicators.
Five male qigong exercisers (ages 53-66 years) were subjects. They have exercised qigong from 3-10 years. Two unipolar EEG (left frontal, left occipital) and other physiological indicators, such as heart rate, cardiac output, breathing rate, respiratory volume and skin temperature were simultaneously and continuously recorded. Blood pressure was measured every 3 min. except during the qigong exercise. One to three control tests and three to five qigong tests were completed for each subject. During the qigong tests and control tests subjects were sitting quietly with eyes closed for 60 min. But in the qigong exercises (11-50 min. in qigong tests) subjects' thought should be concentrated on their own lower Dantian. Control tests and qigong tests in the same subject were completed on the same time on different days.
EEG power spectral analysis was made with 10 m sec sampling time, 1024 points sampling length and 0.25 Hz discriminating rate of frequency. EEG power spectral matrix in time series was made continuously with 216 spectra, each of them to be the average of 5 continuous EEG power spectra. Both were analyzed by a 7T17 signal processor.
Power of delta (2.00-3.75 Hz), theta (4.00-7.75 Hz), alpha (8.00-13.00 Hz), beta I (13.25-20.00 Hz) and beta 2 (20.25-30.00 Hz) bands and the power percentage of each band, and the peak frequency of each band was analyzed. Entropy of EEG was calculated too.
It was found that during the qigong exercise the peak of alpha wave was higher and shifted to the left, power percentage of alpha waves was increased significantly, and alpha waves were shifted to the frontal area and the occipital area; power of delta waves decreased, power percentage of theta waves was increased, the peak frequency of theta rhythm was shifted to the right. Significant exchanges between the frontal and occipital power were not observed. In one of the exercisers, power of alpha in the occipital area is higher than that in the frontal area. In most of them power of the alpha wave in the frontal area is significant dominant. It might be related with the differences of their qigong methods and their own qigong abilities, for which further research would be valuable. The fluctuation of EEG power in various frequency bands and the transportation and concentration of energy in different areas and different frequencies of brain waves during the qigong exercise were shown in the power spectral matrix of EEG. It was helpful in observing the dynamical change processes of EEG during the qigong state.
There occurred correspondent changes of EEG indicators in each of the 5 subjects during several qigong tests. The results were repeated in different tests of the same subject. Individual difference might show the different processes of self-regulation and different qigong abilities of different qigong exercisers.
In the qigong state the increase of orderization of the brain was showed by the decrease of entropy.
It was discussed that EEG changes in qigong, sleep and hypnosis states. It was thought that concentrated thought in the qigong exercise would be a specific optimal human body eigen state —— qigong eigen state.
In the qigong state the changes of EEG may have resulted from the complicated activities between the cortex and sub-cortex structure. It reflected the active self-regulation of the human body' s visceral organs.
