Deep, restorative sleep appears to play a crucial role in memory as we age, according to new research.
For years, scientists have blamed brain atrophy for our declines in memory – for example, our struggles to remember names.
But that may not be the whole story. The new study shows that insufficient deep sleep ”is an important factor in memory decline in older people,” says Bryce Mander, PhD, a postdoctoral fellow at the University of California Berkeley. He led the study, published in Nature Neuroscience.
Deep sleep produces slow brain waves, and they are key to transporting memories from the hippocampus, a short-term storage area in our brains, to the longer-term storage area in the prefrontal cortex, the brain’s ”hard drive,” Mander says.
Without enough deep sleep, those memories may get stuck in short-term storage, he says.
While the shrinking of the brain with age predicts the disruption of sleep, ”the sleep disruption is a better predictor of memory problems,” he found.
Mander measured the brain activity of 18 healthy young adults, mostly in their 20’s, and 15 healthy older people, mostly in their 70’s, as they slept, then tested their memory the next day.
The more brain shrinkage, the less deep sleep the studies’ subjects had gotten, he found. As the quality of deep sleep declined, so did memory. The older adults had less deep sleep, and performed about half as well as the younger adults on memory tests.
Next, Mander will test how to ”jump start” deep sleep in older adults, possibly using electrical brain stimulation, which has been shown to help younger people with sleep issues.
In the meantime, Mander points out that poor sleep habits can disrupt deep sleep. His advice:
- Don’t nap.
- Stay physically and mentally active.
- Don’t talk about your sleep problems.
- For bedtime reading, try the National Sleep Foundation, or the Help Guide site.