In 1924 a German psychiatrist, Hans Berger, author of a book on telepathic phenomena, decided to develop his theory of differing brain waves, which he firmly believed in after performing various experiments on paranormal phenomena. He measured the electrical impulses emitted by an accident victim whose skull had been partly removed. His work showed that brain cell activity, far from being random, was organized into distinct patterns, in the form of waves. The first type of wave to be explored were those with an average frequency of 8 to 14 hertz (cycles per second), and an amplitude of around 100 microvolts. Berger, astonished by their regularity, called them alpha waves.
The discovery was ignored for some years. Then, in 1934, two British Scientists, Lord Edgar Adrian and B.C.H. Matthews, confirmed Berger's findings - regular brain activity could also be measured in normal, conscious subjects that was identical to the alpha frequencies detected by Berger. Persons emitting these waves were in a state somewhere between waking and sleep, both physically and mentally relaxed, with all neurons emitting the same frequency of brain wave.
Berger, meanwhile, had discovered beta waves, with a higher frequency (14 hertz) and a lower amplitude (10 to 50 microvolts). These waves corresponded to a state of vigilance, attention and concentration on exterior objects, while alpha waves, as mentioned earlier, correspond to a state of interiorization. The perfection of the electroencephalogram allowed researchers to measure other types of brain waves:
• theta waves (4 to 7 hertz, 200 microvolts) which are emitted during certain phases of sleep or under certain emotional conditions;
• delta waves (3 hertz or less, 200 microvolts to 1 millivolt amplitude) which characterize deep sleep or a state approaching death.
EEG's provide us with a very general idea of brain activity. W. Grey Walter, who has been conducting research on EEG measurements for years, compares the information provided by an EEG readout to that of a deaf-mute Martian trying to understand human language by examining the grooves in a record.
Nevertheless, alpha waves have attracted particular attention over the last few years. Over 30 kinds of portable bio-feedback devices have appeared on the market, and various fields of study, including medicine, parapsychology, pediatrics, and pedagogy, have been experimenting with ways to use alpha waves for therapeutic purposes.
The media has also done its part to stir up the controversy over alpha waves. Why are people so interested?
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