Electroencephalographic Study of Temporary Connections in Man

Abstract

The electroencephalographic study of the mechanism of formation of temporary connections has received special attention in the last ten years, but the great majority of studies have been concerned with the EEG in animals. These studies cannot but alter some recognized basic concepts of the mechanisms of formation of classical conditioned reflexes. For example, we now know that the formation of conditioned reflexes is not only a mechanism of the cerebral cortex, but one that involves the entire brain from the reticular formation to the cerebral cortex. At the present time, it is generally recognized that the site of the very first “encounter” of the inputs (the conditioned and unconditioned stimuli) is in the brain stem reticular formation; in the process of progressive formation of a conditioned reflex, activity of the neurons of the brain stem reticular formation gradually comes to resemble the activity of the cells of the thalamic reticular formation, and the connections between thalamic and cortical cells are considered to form the basis for the reinforcement and formation of conditioned reflexes. A relatively detailed electroencephalographic study of temporary connections in man has been carried out by Gastaut et al. [12, 13] and studies have been carried out by a number of other workers, including Jasper and Shagass [15], Motokawa [23], Kozhevnikov [5], Stevens [25], and Kratin [6], but the large majority of investigators have described the formation of a particular reflex. We believe it is important that several kinds of indicators be selected to investigate the characteristics and neurophysiological mechanisms of the formation of temporary connections in the human brain.