Here's some welcome news for those of us who didn't sleep so well last night: New research suggests that a short power nap can make us feel and perform better.
The study, recently published online in the journal Neurobiology of Learning and Memory, looked at how much a nap can really help in a memory task. On the first day, the 41 participants all took demographic surveys and IQ tests. Then, for a week, they went back to their normal lives and kept sleep logs of their bedtimes, wake-up times, whether they took naps, and if they drank any alcohol. On the last day, they were asked to sleep one hour less than they normally do. Then, the real testing began.
Back in the lab, participants were presented with individual words and word pairings. They then performed a baseline memory test in which they had to decide as quickly as possible whether they had just seen certain words or pairs. Afterwards, half of the participants were allowed 90 minutes for some sweet, sweet shut-eye; the other half had to watch relaxing DVDs — and stay awake. Finally, all participants performed the memory tasks one more time.
Results showed that everyone did best on the baseline single-word memory task, when the words were fresh in their minds. After napping or "relaxing" for 90 minutes, the nappers' single-word scores decreased, but their paired-word scores remained the same. For the non-nappers, both scores were worse. So, it seems like the nap protected against the effects of continued sleepiness on the word-pairing task, which is a measure of associative memory. Participants didn't always need the whole 90-minute nap to get the effect, either: "Even a short sleep lasting 45 to 60 minutes produces a five-fold improvement in information retrieval from memory," study author Axel Mecklinger, PhD, explained in a press release.
We already knew that just two quick 30-minute naps can help reverse the physical effects of a bad night's sleep, so it's not totally surprising that an hour or so of ZZZs helps with the mental effects as well. So, use this as your excuse to take a nap today.