General laws for the formation of the state of monotony.

Experimental studies have demonstrated that the formation of the state of optimum working ability in conditions of monotonous activity is associated with a decrease (compared to the rest state) in the level of "preventive" arousal of the CNS, manifest on the EEG as an increase in the power of slow rhythms on the background of a selective increase in the level of coherence at frequencies in the alpha rhythm in the caudal areas of the cortex. Prolonged exposure to monotonous conditions leads to increases in the power of slow (theta and alpha(1)) and beta frequencies in the EEG spectrum without marked changes in the level of coherence. Our results, along with published data, were used to propose the hypothesis that unlike the basic states of the sleep-waking cycle (sleep, rest, active waking, etc.), the state of monotony lacks intrinsic ("built-in") self-regulatory mechanisms; this results in instability in the operation of the regulatory systems of the brain. This leads to the appearance of marked periodicity in changes in both the functional state of the CNS and the quality of work performed by humans.