Research suggests link between sleep abnormalities, memory deficiency

By Kristina Kenney
University News Service
April 26, 2012

Texas State University-San Marcos Department of Psychology Assistant Professor Carmen Westerberg led a research study being published next month that suggests sleep abnormalities in older adults can contribute to memory problems.

The research will be published in the May 2012 issue of the Journal of the International Neuropsychological Society and examines the relationships between specific sleep deficiencies and memory deficiencies in both healthy individuals and individuals with amnestic mild cognitive impairment (aMCI), the earliest stage of Alzheimer’s disease.

The other contributing researchers to the study are Bryce Mander, Susan Florczak, Sandra Weintraub, Marsel Mesulam, Phyllis Zee and Ken Paller.

Individuals with aMCI are characterized as having memory problems greater than expected for someone of their age. Westerberg described this condition as a transitional state between having healthy memory function and developing Alzheimer’s disease. Individuals with this condition are still capable of living on their own and completing daily activities, but are at an increased risk of developing Alzheimer’s disease over time.

When electrical activity was measured in the brain for these individuals while they were asleep, the largest disruptions researchers found were diminished amounts of slow-wave sleep, the same stage of sleep that is implicated in memory processing. When sleep from aMCI patients was compared to sleep from healthy individuals of the same age, results suggested that individuals with aMCI were showing significant sleep disruptions beyond what was expected. To the extent that sleep disruptions occurred in either group, memory was also deficient for information learned one day earlier.

The study, which was completed over two years, sheds new light on potential reasons older people may tend to experience memory problems, and implies that efforts to improve sleep may prove useful for helping to offset memory decline that often occurs when individuals reach advanced ages.

For more information about the research being published, please contact Carmen Westerberg at cw54@txstate.edu.