Naps May Increase Productivity, Harvard Study Finds

That midday nap in class might actually help you learn more when you wake up, according to a recent study conducted by Harvard researchers.

The study, published this month in the journal Nature Neuroscience, says that sleeping for at least an hour during work makes subjects better at performing demanding tasks.

The study is the dissertation of Sara C. Mednick, a graduate student in psychology, who worked under the supervision of a professor in Harvard’s psychology department, Ken Nakayama, and a Harvard Medical School professor, Robert Stickgold.

Previously, the researchers had performed experiments that found that at least six hours of sleep improves a subject’s ability to perform a mental task or retain information.

They also found that testing subjects repeatedly within the day made performance grow progressively worse.

“We then thought that if nocturnal sleep helps with learning maybe midday sleep would help boost performance that was deteriorating, which is exactly what happened,” said Mednick.

The team of researchers then began a new study, testing 30 volunteers four times per day over the course of a year to distinguish between the mental acuity of those who did or did not take naps.

During the hour-long tests, which were designed to be visually and mentally draining, subjects had to distinguish between bars flashing across a computer screen.

In the middle of the day, one-third of the group took an hour-long nap, while another third slept for half an hour. The remaining volunteers did not nap at all.

According to Mednick, the group that received no sleep performed progressively worse over the course of the day, taking up to 50 percent longer to perform the task than they had initially.

Those who took the half-hour nap showed little change in performance, she said. But the long nappers, fully refreshed, improved their performance in the repetitive tasks over the course of the day.

Mednick said the finding could have real-world applications.

“I think it is important to connect the deterioration we see in our task with real world repetitive jobs which may cause burn-out similar to the kind we have reported for a very simple visual task,” said Mednick.

“Perhaps napping in these kind of work environments would make workers more efficient and have a long-term benefit rather than the short-term boost that you can get from caffeine,” she added.

—Staff writer Anat Maytal can be reached at maytal@fas.harvard.edu.