REM sleep, stress and search activity. A short critical review and a new conception.

Basing themselves on an analysis of data cited by other researchers and the results of their own investigation, conducted on man and animals, the authors disclose that sleep changes are determined by the type of behavioural reaction to emotional stress: the behaviour that includes components of search activity directed at changing the situation is accompanied by a reduction of REM sleep time; renunciation of search, as in the cases of passive avoidance, neurotic anxiety and depression, is attended by an increase in REM sleep requirement. Presumably, the function of REM sleep is to compensate for renunciation of search in the waking period. The authors suggest a method of appraising the character of reaction to stress by sleep changes--calculation of the time ratio of REM sleep to delta-sleep in the first two cycles.