Sample page: How is an EEG recorded?

The locations and names of electrodes are specified by the International 10–20 SystemDuring scalp EEGs, electrodes are fixed to the scalp with an electro-conductive gel. Electrodes are normally attached to an individual wire, but in some methods caps or nets are used into which multiple electrodes are embedded.

 

The locations and names of electrodes are specified by the International 10–20 System, which is recommended by the International Federation of Societies for EEG and Clinical Neurophysiology. This system ensures that the naming of electrodes is similar across clinical settings. The '10' and '20' refer to the fact that actual distances between adjacent electrodes are either 10% or 20% of the total front-back or right-left distance of the skull.

 

Each electrode's name has two parts. The first part refers to the region of the brain covered – F for frontal, O for occipital, T for temporal, P for parietal (C stands for central and is not a lobe of the brain) – and the second part refers to the exact location (Morgan, 1993).

 

[Page 1.4 from the module The EEG]

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