While We’re Asleep, Our Brains Are Hard at Work
March is National Sleep Awareness Month. We know we should get enough sleep to feel rested and energetic the next day. But did you know that good sleep is also closely tied with brain health? Our brains aren’t idle while we sleep. Sleep could be thought of as the “late shift” of memory. Here are some findings from neurologists:
Sleep is the time when our brains organize memories.
We might remember thousands of things during the day—but most of those memories drift away after a short time. “When we first form memories, they’re in a very raw and fragile form,” said Dr. Robert Stickgold of Harvard Medical School. Sleeping strengthens the memories that we’ve formed during the day, and while we sleep, the brain is sorting through those memories, deciding what to keep—something like opting between “save” and “don’t save” on your computer. These days, learning experts caution students to get a good night’s sleep before that big exam, rather than staying up all night studying. “You can’t pull an all-nighter and still learn effectively,” said Dr. Matthew P. Walker, a sleep scientist from the University of California, Berkeley.
A good night’s sleep helps us remember names and faces.
It can be harder to remember a lot of things as we grow older. Forgetting a person’s name is a common lapse, so researchers from Boston’s Brigham and Women’s Hospital used that for a test to learn more about memory and sleep. “We know that many different kinds of memories are improved with sleep,” said neuroscience researcher Jeanne F. Duffy. “We found that when study participants were given the opportunity to have a full night’s sleep, their ability to correctly identify the name associated with a face—and their confidence in their answers—significantly improved.”
A good night’s sleep lets our brains “clean house.”
While you sleep, your brain is not only filing away memories—it’s also doing a good cleaning. During the day, cellular waste builds up in the brain. This waste can be harmful, and is associated with the development of Alzheimer’s disease. Why do we need to sleep in order to let our brains do their clean-up work? “The brain only has limited energy at its disposal and it appears that it must choose between two different functional states—awake and aware, or asleep and cleaning up,” said Dr. Maiken Nedergaard of the University of Rochester Medical Center. She explained it this way: “You can think of it like having a house party. You can either entertain the guests or clean up the house, but you can’t really do both at the same time.”
Practice good sleep hygiene by keeping a consistent bedtime routine, getting plenty of exercise (but not right before bedtime), avoiding caffeine and alcohol in the evening, and keeping your bedroom dark, quiet and at a comfortable temperature. If you are experiencing sleep problems, talk to your doctor.