Forgetfulness. It's a sure sign that we're getting older. We forget where we parked, forget to bring our coupons to the store or forget why we came to the store in the first place. But what if all of those memory lapses are less a sign of old age than they are a sign of poor sleep?
A new study published in the journal Neuron has found that the brain waves of older adults become out of sync during sleep. And these brain waves may play a critical role in the ability to download new memories. It may not be the sheer act of aging that is causing us to forget; it may be brain waves that lose their rhythm over time.
A good night's sleep
For the study, a team of researchers from the University of California, Berkeley conducted two tests. First, they recruited 20 young adults and asked them to learn 120 pairs of words. Then they let them go to sleep while monitoring their brain waves. Electrodes were used to measure two types of brain waves; slow waves, which fire about every second, and fast waves, called sleep spindles, which occur about 12 times each second.
When the researchers evaluated the young adults the next morning, they found a correlation between the rhythm of these brain waves and the participants' ability to remember the newly acquired information (in this case, the 120 pairs of words.) Those whose fast and slow waves were synchronized remembered more pairs of words than those who did not.
For the second test, researchers repeated the experiment but this time they recruited 32 people in their 60s and 70s. Once again, the participants whose fast and slow waves were in-sync had an easier time remembering the word pairs. But researchers found that the brain waves of these older participants were less synchronized overall.
As you can imagine, it doesn't take much for these brain waves to step out of rhythm.
"If you're like 50 milliseconds too early, 50 milliseconds too late, then the storing mechanism actually doesn't work," Randolph Helfrich a postdoctoral fellow at UC Berkley and one of the authors of the study told NPR.
Regaining your rhythm
Why do the brain waves get out-of-sync as we age? Helfrich and his team think it might have to do with atrophy that occurs in the section of the brain that aids in deep sleep. The more atrophy they noted in the participants, the more out of sync their brain waves were and the more difficulty they had remembering new information.
The good news is that if it is in fact out of sync brain waves that hamper memory, researchers may be able to develop a treatment using electrical or magnetic pulses to stimulate the activity in this area of the brain and get those waves firing in sync again.
"The idea is to boost those brain waves and bring them back together," Helfrich said.
Potentially, this could help older adults who are having trouble with memory loss as well as those suffering from dementia or other conditions that involve memory impairment.
We don't need the fountain of youth. We just need to get our rhythm back.