[The effect of memorization processes on the structural organization of natural human sleep].

The effect of sleep on learning was investigated, comparing results of memorizing and reproduction of an unknown text before and after subsequent sleep, with a detailed analysis of sleep patterns. Psychological tests excluded the possibility of emotional and stress factors. Presleep learning did not influence mean values of such sleep parameters as total sleep time or duration of different sleep stages. The main finding ot the present experiment was a redistribution of stage REM during nocturnal sleep following learning--its increase in the second sleep cycle with a corresponding decrease toward the end of night. Also, individual difficulties in learning were inversely related to REM latency. Changes in sleep patterns after learning didn't influence the total number of sleep cycles. It is suggested that the REM phase of sleep might be involved in the processing of information acquired during wakefulness.