Alpha waves are electromagnetic oscillations in the frequency range of 8–12 Hz arising from synchronous and coherent (in phase / constructive) electrical activity of thalamic pacemaker cells. They are also called Berger's wave in memory of the founder of EEG.
Alpha waves are one type of brain waves detected either by electroencephalography (EEG) or magnetoencephalography (MEG) and predominantly originate from the occipital lobe during wakeful relaxation with closed eyes. Alpha waves are reduced with open eyes and drowsiness and sleep. Historically, they were thought to represent the activity of the visual cortex in an idle state. More recent papers have argued that they inhibit areas of the cortex not in use, or alternatively that they play an active role in network coordination and communication.[1] Occipital alpha waves during periods of eyes closed are the strongest EEG brain signals. They usually can be detected with the naked eye.
An alpha-like variant called mu (μ) can be found over the motor cortex (central scalp) that is reduced with movement, or the intention to move. Alpha waves do not start to appear until three years of age.[2]
Alpha wave intrusion occurs when alpha waves appear with non REM sleep when delta activity is expected. It is hypothesized to be associated with fibromyalgia[3], although the study was too small to be conclusive.
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See also: Binaural beats
  | Alpha wave frequencies and biofeedback - Alpha wave - ArticleWorld |
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