Of all the many, many reasons you should get more sleep — your skin looks better, your mind’s noticeably fresher, it keeps your mood elevated and stable — here’s a particularly compelling one: You make memories while you sleep, and if you don’t get enough of it, well, you could be putting all those recollections at risk.
That’s right. Although the details aren’t totally clear, we know that good sleep plays an important role in a process called “memory consolidation,” which, in the most simple terms, is how memories are made. Here are the basics.
Sleeping Gives Your Brain a Chance to Sort Out the Important Stuff
By definition, a memory is information that’s processed and stored for future use. But think of how much information you take in in a day — all the sights, smells, emotions, facts. There’s no way your mind can store all that. And not all of it even deserves to be remembered. So when your head hits the pillow, your brain sorts through all that information. Anything that’s important goes to your long-term memory, and the rest gets “deleted.”
…And Prioritize Emotional Memories
It’s not just that certain memories get stored while some get the boot — the same goes for specific details in a memory. Like it or not, this applies to both positive and negative emotions. Did you see a bad car accident? You probably remember the car more than the scenery in the background. That’s because while you slept, your brain parsed out the emotional details from the insignificant ones, a practice that’s possibly linked to preserving memories that are crucial to basic survival. But it’s not just the grizzly stuff that gets burned into our brains. Research also suggests that the brain helps protect positive memories by prioritizing them for processing during sleep. In one study, students were given both happy and neutral images to look at. After 12 hours, the group who’d been allowed to sleep was better able to recall the positive images than the group who was made to stay awake.
Sleeping Also Gives Your Brain Time to ‘Soak It In’
A variety of studies have shown that sleeping directly after learning something new increases the ability to recall information or perform the task. In a recent study from researchers at Notre Dame, students were randomly assigned to remember different word pairs. Recollection of unrelated word pairs was significantly better in students who went to bed shortly after learning compared to those who learned the information and then had a full day of wakefulness.
…And Makes Memories More Useful
Thinking about or practicing something right before bed is, “in some sense ‘telling’ the brain what to consolidate,” says Jessica Payne, lead researcher of the Notre Dame study and a well regarded expert on the topic. When you sleep, your brain tells memories where to go so that they can be easily accessed later. In fact, a study published earlier this year showed that even intense training couldn’t make up for lack of a solid night’s sleep when learning new skills.
While we still have to caveat all these studies with the fact that we still don’t know a ton about why we need to sleep, most researchers will agree that in the majority of cases, if you snooze, you don’t lose. You actually win big.