I am trying to better understand the relationship between the placement of EEG electrodes and the quality of the "brainwave" signals they produce.
There is the standard 10-20 system which has me wondering a few things:
- Is the 10-20 system just a standard based on uniform distribution of the electrodes (so as to maximize brain signal collection)? Is it safe to assume one could increase the "density" of electrodes (again, in uniform distribution) and receive better quality signals? In other words, how does the placement & quantity of electrodes affect the quality of the information that can be obtain via EEG?
- Is electrode gel strictly necessary? Is the gel used for adhesion, conductivity or both? I can't imagine it helps much with conductivity seeing the most of the scalp is (typically) covered with hair?