Characterization of states of consciousness based on global descriptors of brain electrical dynamics

Journal/Book: J Parapsychol. 1999; 63: 402 N Buchanan Blvd, Durham, NC 27701-1728, USA. Inst Parapsychology. 143-161.

Abstract: The spatiotemporal dynamics of the electrical field of the brain reflects variations in the global functional state of the brain. Functional states of the brain are related to states of consciousness. A quantitative assessment of the electrical activity of the brain (EEG) as a whole is thus a prerequisite for an objective characterization of states of consciousness. The traditional methods of EEG analysis focused on the frequency representation of local activities. The spatial approach, which takes snapshots of entire brain's field topographies for units of analysis, is better suited for a global assessment of the brain's state. Extending the spatial approach, multi-channel EEG may be represented as a trajectory in the so-called state space: functional states of the brain are reflected by the geometry of the trajectories. A system of three global descriptors was proposed to characterize the trajectories: Sigma, Phi and Omega. These descriptors provide for a global, macroscopic, ''holistic'' description and 3-dimensional visualization of the varieties of brain functional states. The importance of the global approach is illustrated on some experimental results, and its applicability to the psi research and to the altered states of consciousness is briefly discussed.

Note: Article Wackermann J, Inst Grenzgebiete Psychol, Wilhelmstr 3A, D-79098 Freiburg, GERMANY

Keyword(s): EEG; COMPLEXITY; SEGMENTATION; INPUT

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