The International 10-20 System

electrode nomenclature:

Odd numbers on the left, even on the right


z indicates midline electrodes


F = frontal

C = central

T = temporal

P = parietal

O = occipital

A1 and A2 are on the ears.

LC and RC are left and right cheek, respectively.


Dashed electrodes are optional.


Mouseover the image to see a variation on the naming scheme that is sometimes used.