November 14, 2016
AS WE AGE, many things change, including our sleep patterns and habits. While some changes, such as shifting toward an earlier bedtime, are normal biological processes, sleep deprivation is not. Poor sleep can have a host of serious consequences, particularly for seniors. Inadequate sleep can affect learning and memory, and it may even be connected to Alzheimer’s disease and other forms of dementia.
There are three basic functions involved in learning and memory:
Although acquisition occurs when you are awake, a well-rested mind is better at absorbing information than a sleep-deprived one. Recall primarily occurs during wakefulness as well, although dreams are often a form of recall.
But consolidation occurs primarily during sleep. Your brain sorts through the day’s memories, choosing what to keep and what to discard. The “keepers” are then connected with related information. If consolidation does not occur, you will not be able to recall the new fact. That’s why, for example, pulling an all-nighter to cram for an exam is rarely a good idea – you aren’t giving your brain a break in which to process and categorize what you’re learning.
Scientific research is continually reinforcing the connection between sleep and memory. Studies suggest that different types of memories are developed during different stages of sleep.
Declarative memory – the recall of specific facts, like the name of a new acquaintance – is developed during a stage of sleep known as REM, Rapid Eye Movement.
Procedural memory, recalling how to do something such as bake a cake, develops during the deep sleep stages. When aging adults develop poor sleep habits, they disrupt one or both of these crucial sleep stages and damage both the learning and memory processes.
Poor sleep quality and Alzheimer’s disease are closely connected in several ways. People with Alzheimer’s often have difficulty sleeping and may nap or doze rather than sleep through the night. They may also experience “sundowning,” which is a marked increase in agitated behaviors during the evening, possibly as a result of disrupted circadian rhythms.
Sleep disruption can be an early warning sign of Alzheimer’s, and may even be a cause of the disease. Poor sleep quality has been linked with an increase in the buildup of beta-amyloid in the brain, a toxic plaque believed to cause Alzheimer’s. It appears that the brain “detoxifies” during deep sleep, so these toxins can build up and cause damage in those not getting quality sleep.
Many seniors find that as they get older, it becomes more difficult to fall asleep. One theory behind this is that we may produce less melatonin as we age. Melatonin is the hormone that regulates sleep. In addition, many of the physical and psychiatric health problems that are common in advanced age tend to disrupt sleep. Side effects of many medications include sleep impairment.
While sleep loss is common (occurring in about 44 percent of older adults), it is not an inevitable part of the aging process. Sleep loss can have detrimental effects on learning and memory if it becomes a long-term problem. Adults need seven to eight hours of uninterrupted sleep per night for optimum physical health and cognitive function.
If you’re an older adult experiencing sleep problems, you may be able to make behavioral changes, such as cutting back on caffeine or avoiding daytime napping, to help improve your nightly sleep habits. If your insomnia or sleep problems are severe or persistent, talk to your doctor.