The electroencephalogram (EEG) is the record of brain electrical activity obtained by means of an electroencephalograph (Stedman 1990). The term was introduced, in 1929, by Hans Berger in the title of his paper (Über das Elektrenzenkephalogram des Menschen) published in the Archiv für Psychiatrie und Nervenkrankheiten. It was the first of a series of papers in which Berger reported on his research that dealt with the recording of electric currents (action potentials) of the brain in man. Recognition that electrical activity is a natural property of the living brain dates back to detection of electric currents from the peripheral nerves of frogs by a galvanometer reported by Emil du Bois Raymond, in 1848. His discovery that the living brain generates electricity was substantiated independently, in the mid-1870s by Richard Caton (1875) and Vasilij Jakovlevich Danilevsky (1875) who recorded electrical currents and the fluctuations of these currents from the cerebral hemispheres of rabbits, monkeys and dogs (Ban 2011). Yet, it was Berger, who first succeeded with the recording of spontaneous electrical activity of the brain of man, in 1924, using electrodes attached to the intact skull.  By the early 1930s, he introduced electroencphalography, a technique for  recording electrical activity of the brain and showed that the spontaneous waking EEG was “sensitive to” hypoxia, hypocapnia, barbiturates, bromides, caffeine, cocaine, chloroform, morphine, scopolamine and insulin coma (Berger 1929, 1938; Gloor 1969; Fink 1978).  

Ban TA. Preface, in An Oral History of Neuropsychopharmacology - The First Fifty Years:  Peer Interviews (Thomas A. Ban, editor), Volume 2- “Neurophysiology" (Max Fink, volume editor). Brentwood: American College of Neuropsychopharmacology; 2011, p. X-XXII.

Berger  H. Über das Elektrenzenkephalogram des Menschen. Archiv für Psychiatrie und Nervenkrankheiten 1929; 87: 527-70.

Berger  H. Über das Elektrenzenkephalogram des Menschen. Vierzehnte Mitteilung. Archiv für Psychiatrie und Nervenkrankheiten 1938; 106: 577-84.

Caton R. The electrical currents of the brain. Br Med 1875; 2: 278-9.

Danilevskii V Y. Research on the Physiology of the Brain. Moscpw: Thesis; 1875.

Fink M. Psychoactive drugs and the waking EEG. 1966-1976. In: Lipton MA, DiMascio A, Killam KF, editors. Psychopharmacology. A Generation of  Progress. New York: Raven Press; 1978, p. 691-8.

Gloor P. The work of Hans Berger and the discovery of the electroencephalogram. Electroencephalogr Clin Neurophysiol 1969; 28 (Suppl): S1-S36.

Stedman’s Medical ictionary 25^th edition. Baltimore: Williams & Wilkins; 1959. p. 496.

Antonio E. Nardi

July 10, 2014.