Electrophysiologic characteristics of respiratory suspension periods occurring during the practice of the Transcendental Meditation Program.

In a study designed to identify the electrophysiologic characteristics of the Transcendental Meditation Program, 52 periods of spontaneous respiratory suspension (RS) were observed in 18 subjects during the practice of this program. These periods were correlated with some but not all the subjective experiences of pure consciousness. Nineteen RS periods (belonging to 11 subjects) free from any artifact were selected for EEG analysis. The mean total EEG coherence over all frequencies and over nine derivations for TM subjects showed a significant increase during the RS periods as compared to pre- and post-RS control periods. There was no significant change in mean total EEG coherence in a control group of 30 subjects voluntarily holding their breath. The heart rate showed a significant decrease during the RS periods in both the experimental and control groups, whereas there was no significant change in EEG alpha power in either group. These findings extend those of previous studies and help characterize the physiologic correlates of the state of pure consciousness during the TM program.