ELECTRO-ENCEPHALOGRAPHY

Abstract

The present paper is concerned with the bio-electric activity of the precentral and occipital cortical fields in man as recorded from the surface of the head. Berger,¹in a series of carefully controlled studies, has shown that changes in potential of brain origin can be recorded from the surface of the head in man. He observed that these changes in potential are detectable from various regions of the head, since they are obtained when almost any part of the surface is included between two electrodes adequately separated. Furthermore, it appeared from his records that regular rhythms of the same frequency (the 10 cycle alpha rhythm and the beta rhythms of from 25 to 50 per second) are obtained simultaneously from various parts of the head in normal persons; he therefore concluded that the entire brain or any particular region presents one type of bio-electric activity. Tönnies,²Adrian and