By Jennifer Nelson
Need your 40 winks? If you want to learn anything, apparently you do.
A new study provides important physical evidence that sleep helps cement and strengthen new memories.
The study, published in the journal Science, shows sleep after learning causes very specific structural changes in the brain. It seems we grow new brain cell connections that pass information to one another while we’re snoozing. (Apparently restful sleep is an oxymoron where brain cells are concerned.)
Using mice, researchers found that while we may appear restful as we slumber, our cells are hard at work. The brain cells that actively take on new information while we’re awake reactivate during what’s called slow wave sleep, the phase in which brain waves slow down and REM (rapid eye movement) sleep and dreaming stop.
The study also discovered that learning different tasks forms connections in different parts of the brain. The connections, called dendritic spines, enable the flow of information across the synapses.
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.