J Korean Neuropsychiatr Assoc.
1997 Nov;36(6):1125-1137.
Electroencephalographic Changes Induced by Meditation: Spectral and Visual Analysis
- Affiliations
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- 1Department of Psychiatry, Seoul National University College of Medicine, Seoul, Korea.
Abstract
OBJECTIVES
This study was to investigate the EEG changes induced by Danhak which is one of the Korean traditional mediation.
METHODS
Sixteen meditators and 9 controls were recruited. Spectral analysis and visual inspection of EEG during meditation(meditators) and relaxation(controls) were performed. The absolute power and interhemispheric coherence in earth frequency band were obtained. Ratio of change in absolute power and interhemispheric coherence was calculated to compare the EEG changes between meditators and controls. To evaluate episodic changes of EEG with time, all recorded EEGs were reviewed by visual inspection.
RESULTS
Eleven meditators and 4 controls were excluded from the analysis due to drowsiness or poor compliance. Both meditators and controls showed various EEG changes and the degree of variability was more prominent in meditators than in controls. These differences were evident in absolute power of alpha and theta and coherence of beta at frontal, and coherence of theta at occipital. Meditators showed the increase in absolute power of alpha and theta at frontal, and interhemispheric coherence of theta at occipital. In visual inspection, a number of theta bursts were observed in three of 5 meditators and only one theta burst appeared in one control.
CONCLUSION
These results suggest that great variability of EEG change and the appearance of theta bursts is the characteristics of EEG changes of meditators and that the state of meditation Is more diverse and dynamic than that of relaxation.
