Naps are awesome: why you should nap, even if you feel well-rested each morning.

(We are proud to announce our Kickstarter project is now live. Please take a look and we appreciate your support: http://napwell.co/ksJ4bly)

According to a recent Wall Street Journal report, about 34% of U.S. adults nap on a typical day. However, despite this growing number of nappers in the U.S., a prevailing sentiment remains that naps are somehow “for the lazy” and that if we just get enough enough sleep each night, there’s no reason we should nap.

Strong evidence supports the contrary: naps are awesome for you, even if you get enough sleep each night.

A 2002 study published in Nature Neuroscience highlights the daytime deterioration of subjects’ mental acuity over the course of the day.

Daytime Deterioration

Without a nap, daytime performance on (graphic from Dr. Mednick’s TEDx talk “Give It Up For The Down State”)

The authors of the study tried many different things to try and bring the people’s mental state back up. They tried offering money ($25 for each test session if they could get back to their baseline mental ability) – no luck. They tried letting them rest during the day – nope.

What was thing the researchers did that actually got the subjects’ afternoon/evening results back to their morning baseline?

napmoney

Naps performed better than monetary incentive ($25) for getting subject performance back to morning baseline levels.

You guessed it -  an afternoon nap! Short naps (30 min) brought subjects’ results closer to their morning baseline, while long naps (60 min) brought subjects’ results to baseline. The afternoon nap was as good as nighttime sleep for getting the subjects’ performance level up.

Figure 1 from Mednick et al, Nature Neuroscience, 2002.

(Figure 1 from Mednick et al, Nature Neuroscience, 2002.)

While the researchers in the Nature Neuroscience study assessed the subjects’ “performance” via a simple visual “texture discrimination task,” other studies have focused on different metrics. For instance:

  • A NASA study on military pilots and astronauts found that a 40-minute nap improved their performance by 34% and overall alertness 100%.
  • A related study showed that pilots who were allowed to take a 25 minute nap (while the co-pilot was flying) were 5x less likely to nod off than their peers (who didn’t take naps) and were less error-prone during take-off and landing.
  • In a follow-up study by by Dr. Mednick’s group, the researchers gave volunteers a series of creative problems in the morning and asked them to spend the day mulling solutions before being tested late in the afternoon. Half the volunteers were asked to stay awake during the day, the others were encouraged to nap.Those whose naps were long enough to enter REM sleep for a while did 40% better on the test than nappers who didn’t get any REM sleep and non-nappers.*This 40% boost in creativity perhaps isn’t a surprise to readers familiar with the stories of: Paul McCartney (Yesterday), Mary Shelley (Frankenstein), and August Kekulé (proposed ring-structure of benzene), each of whom claimed that their inspirations came while they were sleeping. For more information on sleep and creativity: check out the Wikipedia article: http://en.wikipedia.org/wiki/Sleep_and_creativity

OK, so why does napping help you with all these things? What’s going on when you nap?

When you’re awake, you’re constantly being bombarded by external cues: things you see, hear, and feel. But when you nap, you completely shut off your mind’s interaction with the external world. During this time, your mind gets a break from having take in information and actually has a chance to organize and digest everything it’s learned.

isolated brain

When you nap, you completely shut off your mind’s interaction with the external world. During this time, your mind gets a break from having take in information and actually has a chance to organize and digest everything it’s learned. (image from BBC news)

It’s during this time that your neurons form connections, creating information highways in your mind associating the different things that you know and have learned. Dr. Mednick sums it up in her TEDx talk pretty well:

“Say you’re going on a job interview, or you’re writing a song, or you’re dealing with a relationship – all those waking experiences you have, when you go to sleep, you start to play around with them. You start to associate them with things that you already know about life. You start to dream about them, and start to hypothesis-test. Well what if she said this? Well what if I did that? What if this happened? And then when you wake up, you have a new appreciation for the situation. Your brain is refreshed, the slate is blank, and you’re ready to go out there again and gain new information.”

Want to learn more about napping? Be sure to check out our upcoming posts:

What happens in your brain when you nap?

and

“When, and how long is it optimal to nap for?


Discussion — 3 Responses