Slow-Wave Sleep and Waking Cognitive Performance Among Older Adults With and Without Insomnia Complaints

ArticleinPhysiology & Behavior 66(3):485-92 · May 1999with7 Reads
Impact Factor: 2.98 · DOI: 10.1016/S0031-9384(98)00316-3 · Source: PubMed


    Previous research has shown that healthy young adults with relatively fast reaction times on daytime testing have significantly more nocturnal slow-wave sleep than do age-matched subjects with relatively slow reaction times on such testing. The current study was conducted to examine the relationship between slow-wave sleep and cognitive performance among older adults with and without insomnia complaints. A sample of 32 noncomplaining older (age > or = 60 years) normal sleepers and a like-aged sample of 32 insomniacs, recruited to participate in a larger study, served as subjects. All subjects underwent nocturnal sleep monitoring immediately prior to undergoing a battery of daytime tests that measured simple reaction time, vigilance/signal detection, and complex reaction time. Results from the normal sleepers showed no relationship between daytime cognitive performance measures and a variety of computer-derived nocturnal slow-wave sleep measures. In contrast, insomniac subjects with relatively slow reaction times showed relative deficits in a spectral analytically derived measure of slow-wave power in the 2 to 4 Hz bandwidth. These results suggest that relative performance deficits among some older insomniacs may be related to specific slow-wave sleep deficiencies. However, among older normal sleepers, intersubject differences in performance appear unrelated to slow-wave sleep measures. Additional research is needed to further explore the possible restorative role slow-wave sleep may serve for cognitive functions other than those examined herein.