Scientists at the University of California Berkeley have discovered a connection between poor sleep, memory loss and brain deterioration as we age, which may help develop a treatment to boost the quality of sleep in elderly people to improve memory.
According to a study published Jan. 27 in the journal Nature Neuroscience, UC Berkeley researchers discovered how poor sleep hampers the creation of new memories.
“If it’s true that sleep is a contributing factor to poor memory and aging, then it’s also something that can be targeted, unlike other factors,” sleep researcher Matthew Walker, an associate professor of psychology and neuroscience at UC Berkeley and senior author, told ABC News.
The findings shed new light on some of the forgetfulness common to the elderly that includes difficulty remembering people’s names.
“When we are young, we have deep sleep that helps the brain store and retain new facts and information,” Walker says. “But as we get older, the quality of our sleep deteriorates and prevents those memories from being saved by the brain at night.”
Healthy adults typically spend one-quarter of the night in deep, nonrapid eye movement sleep. Deep slow waves are generated by the brain’s middle frontal lobe. Deterioration of this frontal region of the brain in elderly people is linked to their failure to generate deep sleep, the study found.
For the UC Berkeley study, researchers tested the memory of 18 healthy young adults and 15 healthy older adults by giving them a list of words to remember.
As they slept, researchers measured their brain wave activity. The next morning, they were tested on the words while undergoing MRI scans.
In older adults, the quality of their deep sleep was 75% lower than that of the younger participants, and their memory of the word pairs the next day was 55% worse.
Meanwhile, in younger adults, brain scans showed that deep sleep had efficiently helped to shift their memories from the short-term storage of the hippocampus to the long-term storage of the prefrontal cortex.