Lifestyle changes, such as getting a good night’s rest, can help maintain memory function and may slow cognitive decline in older adults, according to psychology research at The University of Texas at Austin.
Cognitive decline — specifically memory loss — is inevitable and varies between individuals as people age, but UT Austin psychology doctoral student Stephanie Sherman suggests undisrupted, deep sleep could slow down the process.
“Several studies suggest that older adults perform better on attention tasks compared to young adults following sleep loss, promoting a narrative that older adults don't need as much sleep,” Sherman said. “Since sleep quality and quantity decline in aging, it’s important to examine the effects of sleep loss on cognitive processes that are important for every day life.”
Thirty-six healthy adults between the ages of 65 and 75 completed two overnight sessions — a normal night’s sleep, monitored using electroencephalogram (EEG) to record brain waves and measure sleep stages, and a 24-hour period of sleep deprivation — followed by a series of memory and sustained-attention tasks.
Results indicated that participants whose sleep cycles included more slow-wave sleep, or deep sleep, performed better on memory tasks. Because slow-wave sleep declines with age, researchers suggest monitoring sleep cycles could give early indication of cognitive changes associated with both normal and pathological aging, and getting more slow-wave sleep may aid in preserving memory and cognition.
“This shows for the first time that very subtle changes in the sleep-wake cycle are associated with cognitive decline,” said psychology professor David Schnyer, the principal investigator of the UT Austin Cognitive Neuroscience Lab. “This has implications not only for the normal aging process but also changes that are associated with neurocognitive disorders such as Alzheimer’s disease.”
Researchers also found that sleep deprivation led to a 10-percent decline on average in a person’s ability to complete memory tasks that test a person’s capacity to recall previously encountered events, objects and people. The specific type of memory is associated with frontal brain function, an area where executive decision-making processes, such as planning and projecting consequences are thought to occur.
“There is a big debate over sleep loss and whether it affects memory directly or indirectly through a decline in attention,” Sherman said. Previous studies on young adults show that sleep deprivation hindered only attention and not their working memory, but Sherman’s found both attention and memory are independently affected in older adults.
Sherman presented her dissertation “Associations between sleep and memory in aging, in April 2016. This builds on research published in Neuropsychologia in 2015, titled “Hippocampal activity mediates the relationship between circadian activity rhythms and memory in older adults,” in which Sherman found that adults, aged 60 to 80, who had more consistent sleep and wake patterns had better memory function.
“Many people are turning to untested brain-training games to improve or maintain brain functions,” Sherman said. “But research can help us pinpoint lifestyle changes people can make to preserve their memory and overall cognition.”