For EEG recording there is a standard set of electrode positions known as the 10-20 system (Jasper, 1958, IFSECN,1983). The electrode positions are placed at regular 10% and 20% distances between known landmarks and correspond approximately to known underlying regions of the brain. The electrode lettering provides an indication of the region:
Conventionally the sites of the electrodes are established with a tape measure, starting with defining the vertex. This is at the intersection of the line joining the top of the nose (nasion) to the external occipital protuberance (inion), and the line joining the external auditory meati.
On CFAM monitors the user can set up any number of sets of electrode placements to be used for different purposes. Each set is given a unique 8 character name.
Fp1 Left fronto-polar
Fp2 Right fronto-polar
F3 Left superior frontal
F4 Right superior frontal
F7 Left inferior frontal / anterior temporal
F8 Right inferior frontal / anterior temporal
Fz Mid frontal
C3 Left central or rolandic
C4 Right central or rolandic
Cz Vertex
T3 Left mid temporal
T4 Right mid temporal
T5 Left posterior temporal
T6 Right posterior temporal
P3 Left parietal
P4 Right parietal
Pz Mid parietal
O1 Left occipital
O2 Right occipital
The following are extra positions outside the 10-20
System
Cb1 Left cerebellar
Cb2 Right cerebellar
A1 Left ear lobe
A2 Right ear lobe
Pg1 Left pharyngeal
Pg2 Right pharyngeal
