CRITICAL REVIEW: THE TECHNIQUE AND APPLICATION OF ELECTRO-ENCEPHALOGRAPHY

Abstract

THE rate at which scientific knowledge is accumulated depends upon a number of factors the relative importance of which is not the same in the various branches of science. The history of physiology and medicine suggests that their development is becoming increasingly dependent upon the progress of the physical sciences. This is not merely because the physiologist and clinician prefer to describe their observations in physical and chemical terms ; the link is apparent in the first stage of the scientific method, the manner in which the observations are made. The number of new facts discovered with the unaided senses grows smaller ; the range of perception is extended by more and more elaborate tools. This growing dependence of the biologist on the physicist is familiar, but it has been emphasized here because it suggests some reasons for the difficulty of integrating the facts collected in the last ten years by many observers of the electrical activity of the human brain.* The use of modern electrical techniques in electro-physiology has made the collection of facts easier and more rapid, but the subjects in which the facts have been most satisfactorily built into a coherent theoretical structure are those which were most developed before the introduction of the new methods. In lines of study which spring directly from technical advances the tendency is for more problems to be created than can be solved ; worse still, the avalanche of new observations produces a chaos in which a problem can be stated only in the most indefinite terms. An atmosphere is soon created which is congenial to empiricism and deductive speculation ; while the ascetic principles of induc-tive logic are forgotten in the search for facts and applications. The apparent incoherence of the factual premises is likely also to lead to a cynical individualism in the attitude of the various workers toward their subject, and variations of method and terminology arise which make it hard for those who should be colleagues to understand one another, and almost impossible for a newcomer to understand any of them. The short history of electro-encephalography illustrates this process in detail. The electrical phenomena associated with nervous activity were observed almost as soon as there were instruments capable of detecting them, early in the last century, and Caton (1875) showed that electrical changes * The reviews by Jasper (1937) and Fessard (1938) were found most useful as guides to the literature. 359