Difference between revisions 107585901 and 107585902 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 radiation|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 humans. They are also called [[Hans Berger|Berger]]'s wave in memory of the founder of EEG.

''Alpha waves'' are one type of [[Neural oscillations|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.<ref>Palva, S. and Palva, J.M., New vistas for a-frequency band oscillations, Trends Neurosci. (2007), doi:10.1016/j.tins.2007.02.001</ref> Occipital alpha waves during periods of eyes closed are the strongest EEG brain signals. They usually can be detected with the naked eye.{{Citation needed|date=January 2011}}

An alpha-like variant called [[Mu rhythm|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.<ref>Kolev V, Başar-Eroglu C, Aksu F, Başar E. (1994). EEG rhythmicities evoked by visual stimuli in three-year-old children.
Int J Neurosci. 75(3-4):257-70. PMID 8050866</ref>

==History of alpha waves==

(contracted; show full)
[[de:Elektroenzephalografie#Alpha-Wellen]]
[[es:Ondas alpha]]
[[fr:Rythme alpha]]
[[it:Ritmo alfa]]
[[ja:アルファ波]]
[[pl:Fale alfa]]
[[ru:Альфа-ритм]]