Early history of electroencephalography and establishment of the American Clinical Neurophysiology Society.

The field of electroencephalography (EEG) had its origin with the discovery of recordable electrical potentials from activated nerves and muscles of animals and in the last quarter of the 19th century from the cerebral cortex of animals. By the 1920s, Hans Berger, a neuropsychiatrist from Germany, recorded potentials from the scalp of patients with skull defects and, a few years later, with more sensitive equipment from intact subjects. Concurrently, the introduction of electronic vacuum tube amplification and the cathode ray oscilloscope was made by American physiologists or "axonologists," interested in peripheral nerve recordings. Berger's findings were independently confirmed in early 1934 by Lord Adrian in England and by Hallowell Davis at Harvard, in the United States. In the United States, the earliest contributions to human EEG were made by Hallowell Davis, Herbert H. Jasper, Frederic A. Gibbs, William Lennox, and Alfred L. Loomis. Remarkable progress in the development of EEG as a useful clinical tool followed the 1935 report by the Harvard group on the electrographic and clinical correlations in patients with absence (petit mal) seizures and altered states of consciousness. Technical aspects of the EEG and additional clinical EEG correlations were elucidated by the above investigators and a number of others. Further study led to gatherings of the EEG pioneers at Loomis' laboratory in New York (1935-1939), Regional EEG society formation, and the American Clinical Neurophysiology Society in 1946.