Electroencephalography
Article
Electroencephalography, or EEG, records voltage fluctuations at the scalp that arise mainly from synchronised electrical activity in populations of cortical neurons. The recording is made through electrodes placed at standardised positions on the head.
EEG signals contain rhythms over a range of frequencies, commonly described using bands such as delta, theta, alpha, beta, and gamma. These patterns vary with sleep, wakefulness, attention, sensory input, movement, development, medication, and neurological conditions.
Clinical EEG is used in the assessment of epilepsy, altered consciousness, sleep disorders, encephalopathy, brain injury, and other conditions. Event-related potentials are obtained by averaging EEG responses that are time-locked to a stimulus or action.
EEG has excellent temporal resolution but relatively limited spatial precision because electrical signals are mixed and filtered by the brain, skull, and scalp. Interpretation requires attention to artefacts from eyes, muscles, movement, equipment, and the surrounding electrical environment.
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- Source / publisher: Wikipedia
- URL type: WWW
- Credits: Wikipedia
- URL: https://en.wikipedia.org/wiki/Electroencephalography