Difference between revisions 107585930 and 107585931 on dewiki

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

[[Image:eeg alpha.svg|thumb|Alpha waves |400px|right]]
'''Alpha waves''' are [[neural 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.

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==

Alpha waves were discovered by German [[neurologist]] [[Hans Berger]], most famous for his invention of the EEG. Alpha waves were among the first waves documented by Berger, along with beta waves, and he displayed an interest in “"alpha blockage”", the process by which alpha waves decrease and beta waves increase upon a subject opening their eyes. This distinction earned the alpha wave the alternate title of “"Berger’s Wave”".

Berger took a cue from Eastern European physiologist [[Vladimir Pravdich-Neminsky|Pravdich-Neminski]], who used a [[string galvanometer]] to create a photograph of the electrical activity of a dog's brain. Using similar techniques, Berger confirmed the existence of electrical activity in the human brain. He first did this by presenting a stimulus to hospital patients with skull damage and measuring the electrical activity in their brains. Later he ceased the stimulus method and began measuring the n(contracted; show full)

Following this lapse-of-attention line of thought, a recent study indicates that alpha waves may be used to predict mistakes. In it, MEGs measured increases of up to 25% in alpha brain wave activity before mistakes occurred. This study used common sense: alpha waves indicate idleness, and mistakes are often made when a person is doing something automatically, or 
“"on auto-pilot”", and not paying attention to the task they are performing. After the mistake was noticed by the subject, there was a decrease in alpha waves as the subject began paying more attention. This study hopes to promote the use of wireless EEG technology on employees in high-risk fields, such as air traffic controlling, to monitor alpha wave activity and gauge the attention level of the employee.<ref>{{cite web|title=Brain Wave Patterns Can Predict Blunders, New Study Finds|url=http://www.news.ucdavis.edu/s(contracted; show full)[[de:Elektroenzephalografie#Alpha-Wellen]]
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