Monday, 26 April 2010

How to nap

Even naps as short as ten minutes have been shown to provide psychological benefits in terms of reduced fatigue and improved concentration (pdf). But would-be nappers face some strategic decisions, most obviously - does it matter whether I nap in my chair or ought I try to find somewhere to lie down? And then ... if remaining seated, is it okay to lean forwards and rest my head on a desk?

When it comes to napping while leaning back in a chair or car seat, past research has shown that the further you can lean back, the better, at least in terms of subjective fatigue and reaction times. Now Dayong Zhao and colleagues have addressed the leaning forward issue, comparing lying-down napping and leaning-forward napping, and they've found that the former is the most effective, but that the leaning-forward variety still has clear benefits compared with no nap at all.

Thirty undergrads, all regular nappers, had electrodes attached to their heads before lunch. Then they performed an 'oddball' auditory task in which they had to listen to a string of tones and listen out for the occasional one of a different pitch. Next they had lunch before splitting into three groups: one group enjoyed a twenty minute nap lying down; another enjoyed a twenty-minute nap leaning forwards onto a desk (plus pillow for comfort); the final group just spent the same time sitting quietly.

After this, all the participants performed a repeat of the oddball task whilst having their brainwaves recorded via electroencephalography. Zhao's team were particularly interested in the size and delay of the P300 - a brainwave measure of cognitive alertness.

Participants in both of the napping conditions showed benefits compared with their peers who'd been denied a nap. The nappers, leaning and lying, reported being in a better mood and feeling less sleepy and they performed better at the oddball task. When it came to the brainwave recordings, however, the leaning-forward nappers, unlike the lying-down nappers, showed no difference from the control group. Uniquely, the lying-down nappers showed an increased P300 amplitude, perhaps indicating increased cortical arousal on their part.

The message it seems is clear. A post-luncheon nap is beneficial to your mental functioning even if you're forced to rest your head on your desk. However, if you can find somewhere to lie down properly, then do, because the benefits of the nap will be that much greater.
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ResearchBlogging.orgZhao, D., Zhang, Q., Fu, M., Tang, Y., & Zhao, Y. (2010). Effects of physical positions on sleep architectures and post-nap functions among habitual nappers. Biological Psychology, 83 (3), 207-213 DOI: 10.1016/j.biopsycho.2009.12.008

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

8 comments:

  1. Anonymous1:35 pm

    I'll have to show this to my boss! But I wonder, does the fact that the study used only regular nappers affect the outcome? Would non-nappers benefit from napping in the same way? I think you'd have to look outside the undergrad community for that study though.

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  2. Hi Anonymous - I think you're right. You can see why they recruited regular nappers because they needed participants who'd have no trouble having a quick nap for the benefit of the study. As you say, more research is needed to see if these results apply more widely.

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  3. Cool, I'm going to apply this concept right n....zzzzzzzzz......

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  4. What about non-nappers? How would they fair in this test if they did not nap? Would it be the same as nappers who did not nap or different?

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  5. Anonymous3:26 pm

    But how many people actually work in a place that would allow a short nap, even on a person's lunch break? Most office I've been get really, really upset at the "appearance" of employees not actively working.

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  6. I'm sorry but the conclusions you draw in this post (and the researchers draw) are not supported by the setup. Since those undergraduates were "habitual nappers" you cannot generalise it to say that everybody benefits from a short nap. Other studies partly show so but this one doesn't, as equally it might simply show that a habitual napper, when her nap is denied, suffers performance. Also participants were just from a very restricted age group.

    Alternatively, habitually napping could also decrease the performance on non-napping days instead of improving it on napping days.

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  7. Dear Konstantin
    Yes, you're right - this needs to be replicated with non-habitual nappers.

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  8. I personally find it very hard to nap and when I wake up from a nap tend to feel more fuzzy and groggy.... I wonder if my results are normal for other non- nappers? Is that why you don't nap?

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