THE COMPLEXITY OF EEG IN MEDITATION Author: Yang Sihuan//Yang Qinfei//Shi Jiming//Zhang Li Affiliation: Dept. of Physiology, Beijing University of Chinese Medicine and Pharmacology, Beijing 100029 China Conference/Journal: 3rd World Conf Acad Exch Med Qigong Date published: 1996 Other: Pages: 109 , Special Notes: Some tables are only in Chinese abstracts. , Word Count: 225 The paper discusses the change rules of the complexity of EEG in different leads sites of the brain in meditation with the complexity analysis method in nonlinear kinetics to explore the brain functional change, and to find a new method of nonlinear science in study of EEG in the qigong state. Experimental methods 58 healthy university students were divided into two groups: qigong group : 38 (male: 18, female: 20) control group : (20 male: 11, female: 9) The qigong group did meditation for 20 min. and the control group did simulate meditation for 20 min. EEG was measured 10 min. before and after meditation and simulate meditation. The measurement took 2 sec. 2-4 OH2 EEG complex was analyzed according to the definition of complexity by Lempel and Ziv and the algorithms of Kaspar and Schuater. Result 1. Influence of meditation on EEG C(n) change of EEG complexity in meditation (X bar ± SD, n=38) electrode position before in after F3 0.157±0.016 0.146±0.015 0.157±0.023 F4 0.160±0.018 0.150±0.017 0.155±0.019 C3 0.158±0.019 0.149±0.010 0.158±0.024 C4 0.158±0.018 0.149±0.015 0.158±0.017 T3 0.172±0.023 0.163±0.018 0.172±0.027 T4 0.172±0.025 0.163±0.021 0.173±0.027 O1 0.159±0.023 0.158±0.022 0.158±0.023 O2 0.157±0.022 0.155±0.022 0.151±0.021 C(n) change of EEG complexity in simulate meditation (X bar±SD, n=20) electrode position before in after F3 0.154±0.029 0.167±0.043 0.153±0.034 F4 0.155±0.040 0.152±0.044 0.153±0.032 C3 0.155±0.030 0.158±0.045 0.157±0.033 C4 0.158±0.032 0.153±0.037 0.171±0.036 T3 0.184±0.045 0.181±0.060 0.189±0.047 T4 0.173±0.041 0.173±0.051 0.196±0.048 O1 0.188±0.034 0.193±0.056 0.180±0.046 O2 0.174±0.029 0.176±0.055 0.167±0.040 Discussion: From above we found that there was significant difference between EEG time order. During meditation, the complexity measure decreased and the control group did not show this tendency. It suggests that EEG developed from comparatively random disorder to a synchronization harmonious order in meditation.