Here you are again, snug in your bed. It’s been quite a day—for your body, for your brain, and for the system of the two intertwined. Did you do good things for your brain today? Bad things? Did your brain do good things for you, helping you to make decisions, think thoughts, and take actions that make you proud in hindsight? Did you focus, resist temptation, solve problems, remember the things you needed to remember, play well with others, help to grow the brains of those around you, stay generally more happy than you were sad, or at least remain hopeful and optimistic even in the face of bad moods? Overall, do you feel that crisp crackling of your gray matter that is the mark of a day well spent?
Don’t worry: you’ll get another chance tomorrow.
And between now and then is a good night’s sleep. But it seems kind of counterproductive: just think about how much more you could do if you stayed up! It isn’t worth it, and here’s why.
Back in the 1960s, when researchers were allowed to stick needles in people for thirty-eight nights and inject them with drugs like phenobarbital, a study from the Washington University School of Medicine showed that growth hormone secretion peaks during deep sleep. This hormone, so widely abused in professional sports, increases muscle mass and protein synthesis and stimulates the immune system (among other functions). If you want natural HGH, get a good night’s sleep—it’s one job of sleep to repair what you broke down during the day.
Sleep also allows the brain to clear itself of the chemical adenosine, which is a by-product of neuron functioning. While you think and act, adenosine accumulates, and while you sleep, it goes away. In fact, it’s been shown that the accumulation of adenosine is one cue that makes the brain sleepy, and the invigorating effects of caffeine are due in part to the molecule’s ability to block the effect of adenosine in the brain. The longer you stay up, the more you stew in your own adenosine, eventually turning your brain into sauerkraut.
And beauty sleep is for real too. Researchers in Stockholm took pictures of people after a normal night’s sleep and again after thirty-one hours of wakefulness. Then they had sixty-five untrained people rate the attractiveness of these photos. Despite equivalent wardrobe and grooming, the pictures of sleep-deprived people were rated less healthy, less attractive, and more tired compared to the pictures of the same people after they’d slept.
The final benefit of sleep is something you’ve probably heard before: sleep helps you consolidate your memories. But recent research shows that memory consolidation during sleep goes beyond the idea of packaging memories in more efficient ways. Sleep may promote the brain’s overall ability to be plastic—to adapt and transform itself to new stimuli—with more efficient memory being a by-product of this meta-level remodeling that happens overnight. You can see this in the brains of people learning to type: after practicing typing skills, people who slept for eight hours and then took a typing test did a heck of a lot better than people who did the same training and then stayed awake for eight hours.
From visual learning to emotional learning to traditional definitions of memory, sleep lets the brain change itself in ways that optimize what you need while letting go of what you don’t. Basically, sleep is when the brain does the vast majority of the remodeling needed to make tomorrow different from today.
So turn off the light. Turn off the technology. Let go of the stress and machinations of the day—of all the things you should and shouldn’t have done today, and all the things you should and shouldn’t do tomorrow—and get a good night’s sleep. Your brain will be better for it.
Forgive Yourself to Fall Asleep
If you want to fall asleep, forgive yourself. When researchers looked at the thought control strategies of 406 college students, they found that withdrawing from unpleasant thoughts in favor of more pleasing ones works better than trying to control negative thoughts by beating yourself up over them. If your regrets or failures or worries or fears are keeping you awake right now, don’t be ashamed—try to withdraw from these unpleasant thoughts and into gentler remembrances and hopes that can help you put worry to sleep along with your brain.
Photo Credit: Marcos Mesa Sam Wordley/Shutterstock