A landmark study led by North Carolina State University researchers shows that African-American seniors who have trouble falling asleep are at higher risk of having memory problems - raising the possibility that identifying and treating sleep difficulties in the elderly may help preserve their cognitive functioning. The study is the first to examine the link between sleep and cognitive functioning in older African-Americans.
The study, led by NC State psychology Ph.D. student Alyssa A. Gamaldo, shows that older African-Americans who reported having trouble falling asleep tended to do much worse on memory tests than those study participants who did not have trouble falling asleep. Gamaldo says that the difference was particularly apparent in tests related to "working memory," which is the ability to multitask or do two things at once. The study examined 174 subjects between the ages of 65 and 90.
Gamaldo says the findings raise additional questions, which will have to be addressed in future research. For example, Gamaldo says, "it is not clear if lack of sleep is the issue. Is it the quantity of sleep, the quality of sleep, or something else altogether?"
The study raises questions for future research on both sleep and cognitive functioning in the elderly. The findings indicate that sleep may need to be accounted for as a confounding variable in cognition studies targeting seniors. In addition, the findings show that sleep research may need to increase its focus on older adults in order to fully explore the impacts of sleep problems on cognition in seniors.
"If we can better understand how sleep quantity, as well as quality, influences general cognitive functioning, perhaps we could better maintain memory throughout life - including later in life," Gamaldo says.
The study, "The Relationship Between Reported Problems Falling Asleep and Cognition Among African American Elderly," will be published in the November issue of Research on Aging. The study's co-authors are Dr. Jason C. Allaire, assistant professor of psychology at NC State, and Dr. Keith E. Whitfield, professor of psychology and neuroscience at Duke University.
Note to editors: The study abstract follows.
"The Relationship Between Reported Problems Falling Asleep and Cognition Among African American Elderly"
Authors: Alyssa A. Gamaldo, Dr. Jason C. Allaire, North Carolina State University; Dr. Keith E. Whitfield, Duke University
Published: November 2008 in Research on Aging
Abstract: This study examined the relationship between elders' cognitive performance and self-reported trouble falling asleep. Analyses were conducted on 174 older independently living, community dwelling African Americans (M age = 72.74; range = 65 to 90). Cognitive performance was measured using the Mini-Mental State Examination, Forward Digit Span task, Backward Digit Span task, Alpha Span task, and California Verbal Learning Test. Results suggested that individuals who reported trouble falling asleep tended to perform significantly worse than individuals who did not report trouble falling asleep on measures tapping short-term memory and working memory after controlling for age, education, gender, depression, and current health. These results demonstrate that a self-report of sleep difficulty may be a unique predictor of cognitive performance.