Dement's Discovery on REM Sleep Deprivation and Dreaming Sleep

The discovery of a practicable way not only of monitoring dreaming sleeps but perhaps also of controlling it presented a great challenge. Normal subjects always begin a sleep period with slow-wave sleep and do not start their first I REM sleep period for at least 45 minutes, sometimes as long as two hours. I they never begin the sleep period with REM sleep. If they are woken during I die night at the beginning of each REM sleep period and then allowed to I return to sleep, do they pick up where they left off, starting REM sleep, or start ! The night all over again? What is the psychological effect of preventing the dreams of REM sleep?

Dement (1960) woke six subjects in this systematic way over a period of six nights, and found that on the first night they did seem to 'start all over again' I whenever properly woken, so that by the end of the night they had had a good deal of slow-wave sleep and very little REM sleep. On subsequent nights it became more difficult to prevent REM sleep, especially in the early hours, and the number of awakenings that were necessary increased night by night. By the fifth or sixth nights the subjects were hardly getting any sleep at all. On recovery nights, when the subjects were allowed to sleep undisturbed, they took ! More REM sleep than usual, as if they were making up to some extent for the amount lost. These findings are consistent with the idea that REM sleep, and perhaps the dreaming associated with it, is especially important and perhaps die most important function of sleep. Dement (ibid.) also found that his subjects tended to become paranoid when deprived of REM sleep - ascribing sinister motives to the experimenter and [developing all sorts of unreasonable suspicions, as well as having bizarre I experiences such as hallucinations (seeing or hearing things that were not there). Therefore, not only did the subjects' sleep mechanisms rebel against the regime by making more and more attempts to initiate REM sleep during the period of deprivation, and to some extent made up for the amount lost when allowed to do so, but the subjects also showed signs of psychological distress when it was prevented.

However, Dement subsequently established that these psychiatric symptoms were not reliably elicited by REM sleep deprivation (Dement, 1965). Rather, they were probably the consequence of the expectations of the experimenters - the so-called 'experimenter effect'. In this instance the experimenters' expectations were communicated to the subjects through genuine concern for their well-being. Not only were the subjects told of what Dement thought might be the probable results of the regime, but they were also provided with the full-time services of a psychiatrist, to whom they could report any unusual I sensations. After the third day of REM sleep deprivation, little sleep at all was being achieved, and the symptoms that the subjects showed were a combination of the effects of total sleep deprivation and suggestion.

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Despite the fact that Dement performed subsequent experiments in which his subjects showed no psychiatric symptoms after REM sleep deprivation, and that he himself stressed that his early observations about the effects of REM sleep deprivation were probably misleading, the idea that dreaming preserved sanity had been strongly reinforced. It is not uncommon even now to read in works of popular science that this notion has firm scientific support. It has not recalled very few dreams indeed, compared with the control group. Again, while distraction can cause forgetting during the day, this is normally confined to very recent memories that have no obvious meaning (such as unfamiliar telephone numbers that have just been looked up). If briefly distracted from watching a film or television program, we would be very surprised not to be able to remember anything about it afterwards.