When you learn something new, the best way to remember it is to sleep on it. This is because sleep helps consolidate the memories you create throughout the day. It also helps connect new and old memories. You can even come up with new creative ideas when you wake up.
What happens to the memories in your brain when you sleep? How does lack of sleep affect your ability to learn and remember? NIH-funded scientists are gathering data on the complex relationship between sleep and memory. The results may lead to new approaches to help students learn or help older adults remember as they age.
“Before studying, we learned that sleep helps your brain form memories,” said Dr. Matthew Walker, a sleep scientist at the University of California, Berkeley. “Furthermore, sleep is important after learning to help store brain architecture and integrate new information, which means you won’t forget.”
When you have a restful night, your brain goes through several stages of sleep, and dreaming often consists of light sleep, deep sleep, and rapid eye movement (REM). The cycle repeats approximately every 90 minutes.
The non-REM sleep stage seems to prime the brain for better learning the next day. If you lack sleep, your ability to learn new things can decrease by up to 40%. “You can’t pull lighter and learn more efficiently,” Walker said. Lack of sleep affects the part of the brain called the hippocampus, which is the key to new memories.
When you wake up, you collect a lot of memories. Most of them are forgotten during the day. “When we first form memories, they are very raw and fragile,” said Dr. Robert Stiggold, a sleep specialist at Harvard Medical School.
But when you rest, “sleep seems to be a moment of leisure when the brain goes back over new memories and decides what to retain and what not to retain,” Stiggold explains. “Memories of course become stronger during nighttime sleep.” Research has shown that memories of certain procedures, such as playing the piano, can actually improve when you sleep.
Memories appear to be more stable in the brain during deep sleep. After that, REM, the most active stage of sleep, seems to play a role in associating related memories, sometimes in unexpected ways. Getting a full night’s sleep can help with the problem. REM sleep helps process emotional memories, which can reduce emotional acuity.
It is well known that sleep patterns change with age. Unfortunately, the stages of sleep that improve deep memory begin to wane in the late 30s. A study by Walker and colleagues found that adults over the age of 60 had 70% more sleep loss than young adults aged 18-25. Older adults have difficulty remembering things the next day, and memory impairment is associated with reduced depth. sleep Researchers are now looking for ways to improve the deep stages of sleep in this group of seniors.
“Although we have limited medical treatment for memory loss in old age, sleep therapy can be a treatment,” said Walker. “Restoring sleep can improve memory in the elderly.”
For insiders, especially students, Stickgold has additional advice. “Realize that the sleep you get after studying is at least as important as the sleep you get before you study.” When it comes to sleep and memory, he says, “You get very little benefit from cutting corners.”
