Характеристики ЭЭГ в процессе кратковременных самопроизвольных пробуждений разной длительности при изменениях в психомоторной деятельности, вызванных засыпанием

Abstract

During daytime sleep, the changes in the spectral characteristics of the EEG during recovery periods of the psychomotor test with spontaneous short-term awakenings were studied in 17 healthy subjects. The test contained two successively alternating tasks: the “silent” counting from 1 to 10, synchronized with the clicks on the button, and only the “silent” count. The monotonous nature of the test leads to a rapid decrease in the level of wakefulness and in most cases causes falling asleep. The appearance of button clicks is a behavioral indicator of the resumption of cognitive processes inhibited during sleep. Situations were compared for a small (2–5) and relatively large (6–10) number of button presses. The onset of button presses is preceded by the appearance of a generalized alpha rhythm, which decreases during psychomotor activity. At the same time, its power was always greater in a situation with longer periods of observed behavioral activity. The cessation of the button presses is accompanied with the return of the alpha activity power to values observed before the awakening. The EEG alpha rhythm at the reduced wakefulness during short-term awakenings apparently characterizes the activation of the thalamo-cortical mechanism, and is required for the motor interaction of the body with the environment. The absence of differences in the frontal areas at the initial stage of performing short-term and longer-term activity (approaching the full cycle of clicks) suggests that during this period they are involved to the same extent, regardless of the number of clicks. These results indirectly confirm that the observed psychomotor activity, even with a small number of clicks, is not automatic and unconscious, but is accompanied by a reduced, fragmented consciousness.