Electroencephalographic (EEG) Correlates of Some Activities Which May Alter Consciousness

A key problem of finding the most complete and useful theory of consciousness may revolve around how to empirically de- termine different styles or states of consciousness and how to incorporate these within a single paradigm. This was our motivation to start examination of EEG correlates of some activities or substates of consciousness which occur spontaneously or are induced artifi- cially. Our investigations demonstrated more or less characteristic features in 25 subjects practicing the Transcendental Meditation program (increased β power in prefrontal region, increased θ power in left frontal and right temporal regions, increased α power in both temporal regions, and correlation between increased α power and decreased correlation dimension), 6 subjects with 4 types of spiritual music provided to induce musicogenic states (with significant changes in only 3 cases out of 24, where increased θ and α power was observed in only those subjects who have described their musical experiences as very pleasant), 28 subjects of relaxation induced by microwave resonance therapy applied to corresponding acupuncture points (with slightly decreased EEG power in all fre- quency bands, especially in the left central region, which can be ascribed to higher activation of the stimulated left circulatory part of the acupuncture system; it should be also noted that persons not previously subjected to this treatment responded stronger, presumably as a consequence of the more imbalanced acupuncture system), 5 healer/healee, noncontact interactions (with increase in the maximum mean coherence of their EEG patterns in the α band observed only in short 4s time intervals), and 30 subjects for monitoring alert- ness/drowsiness level (with implemented automatic procedure of the neural network classifier to assess the correlation between EEG power spectrum fluctuations related to changes of vigilance level, demonstrating linear separability of the states of alert wakefulness and drowsy wakefulness, allowing very fast data processing and possible real time applications in clinical practice). New technologies applied to the EEG may permit rapid and reproducible identification of different styles or states of consciousness. Such a tool might be useful in evaluating the effectiveness of different techniques for stress reduction and for altering expressions of consciousness.