Revision 107585840 of "Portal:Alpha wave" on dewiki

{{dablink|For the 3D platform video game, see [[Alpha Waves]].}}

[[Image:eeg_alpha.svg|thumb|Alpha waves |400px|right]]
'''Alpha waves''' are [[electromagnetic]] oscillations in the frequency range of 8–12 [[Hertz|Hz]] arising from ''synchronous'' and ''coherent'' (''in phase'' / ''constructive'') electrical activity of [[Human thalamus|thalamic]] pacemaker cells in the [[human brain]]. They are also called [[Hans Berger|Berger]]'s wave in memory of the founder of EEG.{{Harv|Brazier|1970}}

''Alpha waves'' are one type of [[brain waves]], commonly detected by [[electroencephalography]] (EEG) or [[magnetoencephalography]] (MEG) and predominantly found to originate from the [[occipital lobe]] during periods of waking relaxation with the eyes closed. Conversely alpha waves are attenuated with open eyes as well as by drowsiness and sleep. They are thought to represent the activity of the visual cortex in an idle state. Occipital alpha waves during periods of eyes closed are the strongest brain signals of the EEG. They usually can be detected with the naked eye.

An alpha-like normal variant called [[Mu rhythm|mu (μ)]] is sometimes seen over the motor cortex (central scalp) and attenuates with movement, or even with the intention to move.

== References ==

* {{Harvard reference | Surname = Brazier | Given = M. A. B. | Title = The Electrical Activity of the Nervous System | Year = 1970 | Publisher = Pitman | Place = London}}

==See also==
* [[Electroencephalography]]
* [[Sensorimotor rhythm|SMR]]
* [[Sensory Integration Dysfunction]]
* [[Holonomic brain theory]]
* [[Epilepsy]]
* [[Sleep]]
* [[Mu wave]]
* [[Beta wave]]
* [[Delta wave]]
* [[Gamma wave]] 
* [[Theta wave]]
* [[Theanine]]

{{Neuroscience-stub}}

[[Category:Medical tests]]
[[Category:Meditation]]
[[Category:Electroencephalography]]

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[[ru:Альфа-ритм]]