SOME CORRELATES OF RAPID EYE MOVEMENT SLEEP IN THE NORMAL AGED MALE

It was concluded that the present findings reflect a general physiological decline with age, affecting amount of REM sleep, erection, cognition and other aspects of functioning, and probably due to the deterioration of the central nervous system.

Abstract

Levels of cognitive functioning and drive have been hypothesized to influence amount of rapid eye movement (REM) sleep. The aim of this investigation was to study the effects of cognitive and drive functioning on amounts of REM sleep in the aged. Level of drive was defined by 1) the individual's proportion of REM periods accompanied by full erection and 2) his reported frequency of sexual outlet. Level of cognitive functioning was defined by each individual's Wechsler Adult Intelligence Scale (WAIS) score and Wechsler Memory Scale score. Strength of grip was also studied as a control measure. Sleep data were available from 16 normal male subjects, aged 71 to 95 years. Amount of erection was measured on strain gauge nights and reported frequency of sexual outlet was obtained from interviews. The WAIS, Wechsler Memory Scale and strength of grip evaluations were completed after the sleep nights. Amount of REM sleep correlated significantly with a) proportion of REM periods categorized as full erection (p < .05), b) the WAIS digit symbol subtest (p < .01) and c) the WAIS performance and Wechsler Memory Scale scores (combined) (p < .05). The significant correlations between amount of REM sleep and frequency of full erection were not considered confirmation of the drive hypothesis because 1) significant correlations were also obtained between REM sleep and nondrive measures, and 2) there were difficulties in interpreting the correlations in terms of a drive theory. We did not find as high correlations between amount of REM sleep and WAIS performance and Wechsler Memory Scale scores for the aged as had been previously reported. Also the significant correlation between amount of REM sleep and the WAIS digit symbol subtest was not considered a clear confirmation of the cognitive hypothesis, since it may have reflected a psychomotor slowing with age as well as lowered cognition. Therefore, it was concluded that the present findings reflect a general physiological decline with age, affecting amount of REM sleep, erection, cognition and other aspects of functioning, and probably due to the deterioration of the central nervous system.