AMHERST, Mass. – Neuroscientist Rebecca Spencer at the University of Massachusetts Amherst recently launched sleep research in older adults that could provide new directions for treatment of age-related memory decline. If sleep patterns are at the root of declines in learning and memory for some tasks in older adults, “Perhaps we can design new treatments, adding those that enhance sleep, for people at this stage of life,” she says.
Spencer received a five-year, $1.9 million grant from the NIH’s National Institute on Aging to study the relationship between memory consolidation and sleep architecture as measured by polysomnography, recording biophysiological changes during sleep, in men and women 60 to 80 years old compared to young people.
In a series of experiments expected to involve about 380 participants, half of them over 60, Spencer and colleagues will try to define how age-related sleep changes interact with memory, because “it seems that not all types of memory are affected by changes in sleep patterns as we age,” she explains.
“If we know there’s a link between sleep quality and memory and cognition in some cases, then we can target sleep to protect cognitive abilities in the older person,” she points out.
Other than memory, cognitive abilities that may be affected by sleepinclude decision-making, creativity and emotional processing. Processingemotional events, such as the death of a friend or loved one, is animportant part of life for many older adults and represents an area not wellstudied in relation to sleep, Spencer says. “It’s very exciting that we’regoing to explore that relationship in this investigation.”
“We’re trying to further define when sleep changes will affect aging,” she adds. This work could help to guide such decisions as whether a person should use sleep medication or instead learn behavior strategies to enhance sleep. “Learning good sleep habits can often improve the quality of your sleep,” says Spencer. “People can learn to protect and promote their good sleep, something most young adults don’t even think about.”
Sleep researchers know that one key function of sleep is memory consolidation, which enhances learning on certain tasks in people younger than about 35 years old. For example, young adults’ performance on a simple task that involves sequence learning improves after a 12-hour interval with sleep compared to a 12-hour interval without sleep. In this type of task, subjects press piano-like keys in response to a cue. Cues come up in a sequence, and learning it lets one finish faster. Sometimes called skill learning, it is the type of learning related to learning to tie shoes or ride a bike.
But this sleep benefit is not seen in adults over about 35. For them, preliminary studies suggest that sleep-dependent memory consolidation remains intact for a non-motor cognitive task such as learning word-pair associations, but not for sequence learning.
The UMass Amherst study will include new sleep quality markers not explored before in older adult participants, Spencer says. Polysomnography, which involves putting several electrodes on the scalp and monitoring wave patterns during sleep and dreaming, allows neuroscientists to map sleep architecture over many hours and to compare patterns between age groups.
Increasingly, research suggests that sleep time is reduced in older people, but sleep quality is more important. “If sleep quality is strong, evidence suggests this matters more than time spent in each sleep stage. For example, slow wave sleep is often obliterated in older adults and could reduce memory. On the other hand, if other brain signals are still strong, memory may be preserved. This new series of experiments will be able to explore these questions with qualitative measures.”
Some participants will be asked to spend the night in a sleep laboratory for this work, while others will use portable sleep monitoring equipment in their own homes, Spencer says. Participants’ memory for a spatial game, a motor sequence or emotional material will be assessed in addition to a battery of tests which assess basic neuropsychological functions.
Spencer says, “People are hungry for practical information about their sleep quality. I often give talks to retiree groups and seniors, offering common sense tips such as that the body temperature needs to be at its daytime low in order to sleep well. Our sleep research helps to remind people that we spend a considerable time sleeping, up to one third of our lives. Good quality sleep warrants attention and can very much enhance quality of life.”
To volunteer for this research, contact Spencer at 413/545-4831.