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Electroencephalogram
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The electroencephalogram, or EEG, studies the brain's electrical activity. Electrodes are stuck onto the scalp, that is, on the outside of the head, without entering the body. It is used mainly to evaluate epileptic seizures.
What those electrodes measure are the electrical potentials produced by the neurons of the cerebral cortex lying right underneath. When many neurons in the same area fire at the same time, their small potentials add up and create an electric field with two poles, one positive and one negative. It is the murmur of the crowd, not the voice of one neuron.
That recording is read by frequency, that is, by how fast the waves go: alpha, beta, theta, and delta. What shows up during a seizure is a supersynchronous neuronal discharge, all the neurons at once, arising from an abnormal brain network.
In brief
An electroencephalogram studies the brain's electrical activity with electrodes on the scalp, and is used mainly to evaluate epileptic seizures.
It measures the potentials of neurons in the cortex underneath: the sum of postsynaptic potentials from a region firing at once creates a field with two poles.
It is the murmur of the crowd, not the voice of one neuron.
The usual frequencies are alpha, beta, theta, and delta; in a seizure a supersynchronous neuronal discharge arises from an abnormal brain network.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingElectroencephalogram, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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