Wiktionary
n. (context neurology English) An electrical signal produced by the brain while the subject is relaxed.
WordNet
n. the normal brainwave in the electroencephalogram of a person who is awake but relaxed; occurs with a frequency of 8-12 hertz [syn: alpha rhythm]
Wikipedia
Alpha waves are neural oscillations in the frequency range of 7.5–12.5 Hz arising from synchronous and coherent (in phase or constructive) electrical activity of thalamic pacemaker cells in humans. 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, 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. Occipital alpha waves during periods of eyes closed are the strongest EEG brain signals.
Alpha waves can be quantified using Quantitative electroencephalography (qEEG) using freely available toolboxes, such as, EEGLAB or the Neurophysiological Biomarker Toolbox.
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 seem not to appear until three years of age.
Usage examples of "alpha wave".
In the alpha wave the potential varies by about 20 microvolts in a cycle of roughly 10 times a second.
The alpha wave is clearest and most obvious when the subject is resting with his eyes closed.
Rachel grabbed the tracing, which now displayed only the uniform alpha wave of alpha coma.
Burke looked up from the alpha wave pattern undulating across the monitor.
Yet leave in enough alpha wave state to enable them to alter their gestalts.
Since the light was not operating on his alpha wave frequency, Parker wasn't entranced .
Well, your alpha wave patternthe normal wave output of your brain while at restis totally out of the ordinary.
With such training, an individual attached to an electroencephalograph and a radio transmitter could, in principle, send quite complex messages in a kind of alpha wave Morse code, merely by thinking them in the right way.