The subjective assessment of normal sleep patterns

Abstract

“When we consider the immense human significance of sleep, the absolute necessity for us to spend a considerable part of our lives in abject mental annihilation, it is remarkable how little we know about it. …” In these words, Sir John Eccles introduced the recently published Ciba Foundation Symposium on “The Nature of Sleep” (3), in which are described many of the advances which have been made in recent years in our attempts to understand the phenomena which are involved in the state of sleep. In one of the papers included in this Symposium, Bremer (2) reviews the work which has been reported since 1954 on the neurophysiological mechanisms involved in sleep. The relationship of dreaming to the depth of sleep has been investigated by such workers as Kleitman (5), Dement (4) and Wolpert (11). These studies have been made possible by the application of modern techniques of measuring mental activity. The use of electroencephalographic methods has allowed an approximate classification of the different levels of sleep which enables different workers to adopt a standard frame of reference. Measurements of rapid eye movements and of changes in muscle potential during sleep have provided more objective methods of assessing dream activity. Other recent studies have attempted to make an objective assessment of the physical and mental effects of sleep deprivation (Morris et al., 7, Bliss et al., 1, Murray et al., 8, Wilkinson, 9, Williams et al., 10).

A Survey of Sleep Habits and Sleeping Difficulties in an Elderly Swedish Population

“…Of the males 79.3% lived with someone else compared to 59.6% of females (x2=37.5; p<O.OOl), and 26.0% of females were widowed versus 9.1% of males (x2=40.8; p<O.OOI). 18.9% stated that they had sleep problems. Females more often than males, 23.8% versus 13.3% (x2=15.1; p<O.OOl).…”

A comparison of the effects of chlormezanone and nitrazepam on sleep.

“…The volunteers were selected because they thought they were poor sleepers and to mirror those who frequently take sleeping pills, in that they were middle-aged and included more women than men (McGhie & Russell, 1962). The baseline recordings show that, as a group, they took about 40 min to fall asleep.…”

Perception of sleep in the elderly

“…The discrepancies between estimates of sleep parameters of satisfied and unsatisfied sleepers are more or less marginal. This finding may be associated with individual variability in sleep requirements (McGhie & Russel, 1962). A person who feels refreshed after 5 hours of sleep will not complain if he or she obtains this amount of sleep, but the reverse will probably be true for a person who needs 7 hours of sleep to feel refreshed.…”

“…This concern is particularly warranted for the elderly (Morin et al, 1993) because sleep normally changes in a negative direction with advancing age. Increased sleep onset latency (SOL) and increased wake time after sleep onset (WASO) constitute normal age-related changes in sleep (Miles & Dement, 1980). This may indicate that patients whose complaints are based on unrealistic sleep expectations, do not suffer from any sleep disorder.…”

“…Volk et al, 1991). Studies have also demonstrated large inter-individual differences in sleep parameters (McGhie & Russel, 1962). Subjective reports on disturbed sleep, therefore, seem to be important as sleep quality in the first place is a subjective phenomenon.…”