ABSTRACT
This chapter reviews the physiological changes found with age in sleep and cognition. It analyzes are the effects of the most frequent primary sleep disturbances, such as insomnia and daytime sleepiness, on the neuropsychological functioning of elderly people. Age may be the factor that has the greatest influence on the physiology and physiopathology of sleep and, as occurs in other organic and psychophysiological functions, some changes that affect both its amount and quality become evident in the sleep of elderly people. In regard to sleep, some changes occur during aging that principally alter the cerebral bioelectric activity, the sleep architecture, and its circadian rhythm. With aging, progressive desynchronization, decrease in amplitude, and fragmentation of the cerebral rhythms are observed in the electroencephalographic recording. Even though the elderly people spend many hours in bed, their nocturnal sleep is shorter and less consolidated than that of younger adults.
