Studies have shown that getting a good night’s sleep is no longer just for resting the body; it’s also a great way for people’s minds to reboot and lock-in information learned throughout the day.

But now a study recently conducted at the University of California, Berkeley, suggests that sleeping before learning something is just as important, with about 100 minutes of sleep suggested as the ideal amount.

In a study done on 44 volunteers, study co-author Matthew Walker, explained that the volunteers who took a nap before undergoing a memorization test ended up with higher test points than their counterparts who did not take a nap.

Walker, a professor of psychology and neuroscience, said that what they had discovered is that the nonrapid eye movement (NREM) phase of sleep is the most closely related to the boost in mind activity provided by napping.

To test their theory, Walker and his associates had the volunteers (27 females, 17 males) come to the sleep lab at around noon. They were then asked to memorize the names and faces of 100 individuals. They were tested right after to see how well they were able to match the faces to their names.

At around 2 p.m., half of the volunteers were asked to take a nap for an hour and 40 minutes, the rest were told to stay awake and to go about their normal daily activity.

Later in the day, after a period of time that allowed the nappers to shake off the sleep, they again administered a memory test to both sets of volunteers.

Their first major discovery? A person’s learning ability starts to degrade as the day goes by. Volunteers who didn’t take a nap before taking the second test failed miserably.

Additionally, those who did take a nap not only did better than their counterparts, they also did better than themselves; nappers averaged an increase of 10 percent in their evening test over their own morning test, leading Walker to believe that the afternoon nap not only re-energized the subject, it also “provided a memory boost.”

Researchers were also able to identify the possible reason for the memory boost.

It’s called a sleep spindle, and it’s described as “a short, synchronized burst of electrical activity.”

The sleep spindles last about a second each but can happen about a thousand times when someone is in NREM sleep.

The spindles also vary from person to person, but Walker and his team found that those who had more, particularly in their frontal lobes, tended to retain information better.

Sleep spindles free up memory space
Walker believes the spindles work as a form of conduit that transfers information from the brain’s hippocampus (a small part of the brain where memories are said to be made) to one’s pre-frontal cortex (“long-term storage”), in essence opening up more ‘memory space’ in the hippocampus.

He further explained that NREM sleep and the frequency of sleep spindles change throughout the course of a person’s life. The older one gets, the lesser the frequency; a possible explanation for ‘senior moments.’

In closing, Walker, whose study is to be published in the journal Current Biology, hopes to use this to underscore the importance of sleep.

“Somewhere between infancy and early adulthood, we abandon the notion that sleep is useful,” he said, “That needs to change. Sleep is doing something very active for things like learning and memory. I think for us…to stop thinking of sleep as a luxury rather than a biological necessity is going to be wise.”

Source: LiveScience