A brief nap can help people quickly restore energy and improve work efficiency. Recently, a study has found that taking a nap can enhance the brain’s ability to solve problems, and some previously challenging issues may be resolved effortlessly after waking up.
In this study, researchers from Texas State University in the United States tested analogical problem-solving methods, which involve the brain using successful strategies applied to similar problems in the past to solve current issues.
They discovered that compared to those who did not nap, individuals who took a nap were better at seeking solutions through these cognitive pathways.
To conduct this study, researchers recruited 58 participants aged 18 to 29 and randomly divided them into two groups: one to nap and the other not to nap, for an experimental task.
During the experiment, all participants were presented with a series of problems one at a time and were given 3 minutes to answer each question. Subsequently, the researchers showed them the solutions and asked them to remember them.
In the next stage, the participants were presented with a set of structurally similar but new problems and were asked to solve them without seeing the solutions, once again with a 3-minute time limit per question. These questions were used to assess whether they could apply their knowledge from the previous set of problems to solve new, structurally similar ones.
In a later phase, 28 participants (the nap group) were allowed to take a 110-minute nap in a quiet room in the laboratory, while their brain activity was monitored using electroencephalography (EEG). Another 30 participants (the no-nap group) remained awake using drugs or alcohol.
At the end of the rest period, all participants were asked to try to solve the problems they couldn’t solve earlier. They also underwent a memory test to recall the solutions to the first set of questions and to evaluate the similarity between the first and second set of questions.
Researchers found that participants who took a nap solved more of the previously unsolved problems compared to those who did not nap, and their likelihood of problem-solving was associated with the amount of rapid eye movement (REM) sleep they had during the nap.
This effect was not due to differences in initial problem-solving abilities between the two groups because both groups had a similar rate of solving problems before the rest period.
Researchers further discovered that individuals who napped were more capable of recognizing the similarities between the first and second set of problems.
In their report, the researchers noted that this study demonstrates that sleep can enhance the ability to solve previously unsolved problems, with REM sleep, associated with memory consolidation and emotional processing, being particularly crucial.
They wrote, “The current results suggest that when a problem seems unsolvable, ‘sleep on it’ may have some merit, especially if sleep includes REM sleep.”
They stated that REM sleep may play an essential role in fully leveraging past experiences by establishing and strengthening correlations that are not readily apparent when awake.
Moreover, when individuals need to actively recombine elements of a problem to solve it, REM sleep may be necessary.
The findings of the above study were published in the Journal of Sleep Research.
As for how long people should nap during the day, several previous research results have suggested that keeping nap time within 30 minutes can enhance the benefits of napping while reducing the potential negative impact of napping too long.
Research has shown that prolonged napping can pose long-term risks to the body, such as an increased risk of cardiovascular disease, Alzheimer’s disease, and premature death. (For more information, click here.)