In the context of recording brain-related electrical activity, electrodes are composed of a conducting metal of one sort or another. In general, the best sort of electrode to use when recording 5-30
microvolt activity, are those made of silver/silver chloride. These reduce the ever-present limitation of the detection of activity in certain amplitude ranges.
There are two general sorts of electrodes employed in
EEG recording:
intracranial electrodes and
scalp electrodes.