The hydro-electroencephalogram, a novel method of EEG recording

A novel method is described of recording EEG by means of electrodes in de-ionised water in which the scalp is immersed. It permits large numbers of closely packed electrodes to be connected quickly both in the plane of the scalp and three-dimensionally. A common reference potential can be derived from the whole immersed scalp. The technique should be suitable for the practical application of mathematical methods of source location where large numbers of electrodes are required.