Need to Solve a Problem? Try Taking a Deep Power Nap for an ‘Aha’ Moment, Research Suggests
A new study finds that entering N2 sleep—a deep phase of non-rapid eye movement sleep—may help lead to more “eureka” breakthroughs
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Need to solve a problem? You might want to sleep on it—for about 20 minutes.
New research suggests that taking a quick, deep nap may help lead to a “eureka” moment, as scientists reported last week in the journal PLOS Biology.
For the study, researchers recruited 90 individuals between the ages of 18 and 35 who did not have a sleep disorder. They asked participants to complete a task that involved watching rapidly flashing dot patterns on a screen, then using a keyboard to indicate the direction of the dots.
The researchers didn’t tell the participants, but partway through the task, they introduced a trick: They began linking the direction of the dots with a specific color. Fifteen participants figured out this predictive workaround on their own and were excluded from the remainder of the experiment.
The 75 other participants were each led into a dark, quiet room and hooked up to an electroencephalogram (EEG) monitor that measured the electrical activity in their brains. Researchers instructed them to try to fall asleep for a quick nap.
Once they woke up 20 minutes later, the participants tried the computer task again. Most—but not all—of them figured out the color-direction connection after their brief snooze. Their ability to suss out the strategy seems to be linked with the depth of their sleep: 85.7 percent of the people who reached N2 sleep during their nap figured it out, compared with just 63.6 percent of those who reached N1 sleep and 55.5 percent of those who did not drift off to sleep.
N1 and N2 are the first of three phases of non-rapid eye movement sleep. N1 is a type of light sleep that typically lasts less than ten minutes, right after a person falls asleep. The next phase, N2, is deeper and typically lasts 30 minutes to an hour; it’s more difficult to wake someone up from N2 sleep. (N3, the last phase before rapid eye movement sleep, is even deeper.)
Did you know? Stages of sleep
- Sleep is classified into periods of rapid eye movement (REM) and non-rapid eye movement (NREM). NREM sleep has three progressively deeper phases: N1, N2 and N3.
- REM sleep is when you have dreams, and your body prevents your muscles from moving so you don’t act them out. While babies might spend 50 percent of their sleep in REM, that number drops to about 20 percent in adults.
Researchers do not fully understand the neural processes at play—that is, how and why a short nap seems to help people solve problems. But they suspect that, after napping, the brain is “more plastic and receptive to new ideas,” lead author Anika Löwe, a neuroscientist at the University of Hamburg in Germany and the Max Planck Institute for Human Development, tells Constanza Cabrera of El País.
They also found a link between the participants’ “a-ha” moments and the steepness of their spectral slope, an EEG measurement associated with deeper sleep. They hope the EEG spectral slope might be a clue to the mystery of why power naps seem to trigger moments of insight.
This study did not directly compare participants who rested with those who did not take a break at all. But, in earlier experiments that did not include the opportunity to nap, only 49.5 percent of participants figured out the color strategy—so, the researchers suspect a power nap might “help humans make connections they didn’t see before,” says co-author Nicolas Schuck, also a neuroscientist at the University of Hamburg and the Max Planck Institute for Human Development, in a statement.
Some artists and innovators appear to have intuitively understood that taking a short nap could help boost their creativity. Whenever Thomas Edison got stuck, he reportedly liked to take a quick snooze while holding steel balls in his hands, so that if he fell into a deep sleep, the noise of the balls clattering to the floor would wake him up. Salvador Dalí employed a similar napping technique while holding a heavy key. They were likely entering N1 sleep, which research has found can be helpful for solving math problems.
The new study appears to offer more evidence in favor of N2 sleep. However, N2’s usefulness for solving problems likely depends on the type of task at hand.
“Maybe both [N1 and N2] sleep stages matter, but for different types of cognitive processes that we have to isolate to understand better,” says Delphine Oudiette, a neuroscientist at the Paris Brain Institute who was not involved with the new research, to New Scientist’s Christa Lesté-Lasserre.
