By Jennifer Nelson
After a particularly trying day, many of us need time to “process.” But despite our attempts to think through or solve stressful situations while awake, a lot of our emotional processing takes place between the sheets.
It seems this could be the purpose of our dreams.
“Dreaming diffuses the emotional charge of an event and so prepares the sleeper to wake ready to see things in a more positive light, to make a fresh start,” writes sleep researcher and psychologist Rosalind Cartwright, author of, “The Twenty-four Hour Mind: The Role of Sleep and Dreaming in Our Emotional Lives.”
Scientists have been debating the purpose of dreaming since the 1970s. Some thought dreams served no purpose; others thought it was our ancestors’ way of gearing up for a fight.
Now researchers who studied the brains of mice have theorized that REM (rapid eye movement) sleep is when we process information, make new connections between neurons and essentially work out our issues, which gives deeper meaning to the phrase “sleep on it.”
When people don’t get REM sleep (meaning they don’t dream), they have a more difficult time processing complex emotions during the day. Persistent sleeping problems, scientists have shown, can lead to depression and anxiety.
In studies of people going through a loss such as a divorce or the death of a loved one, those who were depressed had the least emotional dreams, while those who coped well had highly expressive dreams. In essence, those who were coping well were working out their feelings in their dreams.
Likewise,dreams may serve as a dress rehearsal. When people in love dreamed about weddings or athletes dreamed about sporting competitions, dreamers were mentally preparing for their future. Cartwright explained the brain takes the emotionally raw material of real life and helps you process it in the dream world. What we see and experience in our dreams might not be real, but the emotions behind the experiences certainly are.
We dream about every 90 minutes, each dream cycling longer than the last, and most people have about four to six dreams each night during REM sleep. Apparently, all this dream-work is simply preparing us to cope with our lives.
The mice formed these connections after just six hours of learning something new.
“Imagine a tree that grows leaves (spines) on one branch but not another branch,” said Wen-Biao Gan, professor of Neuroscience and Physiology at NYU Langone Medical Center in New York and author of the study. “When we learn something new, it’s like we’re sprouting leaves on a specific branch.”
Interrupting sleep prevents the leaves from growing on your brain branches—no wonder it’s hard to remember anything new after a few nights of fitful sleep. “We’ve known for a long time that sleep plays an important role in learning and memory. If you don’t sleep well you won’t learn well,” Gan said.
Want to learn something better, memorize facts or study for an exam? Hit the sheets after committing the information to memory. The mice in the study logged seven straight hours of shut eye after learning new behaviors. Scientists think sleeping well the night after learning new material just may be the key to acquiring all that new information.