Aha! How a nap can help you have a moment of clarity — if it’s done right

Have you ever been faced with a difficult decision and been told to “sleep on it”?

These grandmotherly words of wisdom can feel frustrating in the moment — but a new study in the journal PLOS Biology suggests there’s actually something to them.

Researchers at the Universität Hamburg in Germany set out to understand the neurological mechanism behind the elusive “aha” moment, when everything suddenly clicks.

They asked 90 people to complete a deceptively simple task that involved tracking dots across a screen — unbeknownst to them, the researchers had a trick up their sleeves.

After a few rounds, participants were given a 20-minute nap and their brain activity was tracked.

The results showed that people who reached a deeper stage of sleep, known as N2, were significantly more likely to figure out the task when they returned to the game than those who didn’t.

A whopping 86% of deep sleepers had their eureka moment, compared to just 64% of those who only reached light sleep and 56% of people who stayed awake.

Even those in the shallow sleep camp fared better than the control group from a previous study, where only half of the participants cracked the code without any naps.

These findings suggest that anyone looking for a breakthrough might want to power down rather than power through.

“I think a lot of us have made the subjective experience of having important realizations after a short nap. It’s really nice to not only have data on that, but also a first direction of what processes are behind this phenomenon,” said first study author Anika Löwe.

“What really struck me when telling people in my environment — particularly creatives — about these findings was how much they resonated with people,” she added.

“Many of them could relate to our results with a personal experience of having a (creative) breakthrough after a nap.”

More research might be needed to pin down why this is, but the study’s authors posit that electroencephalogram (EEG) patterns revealed a “steeper spectral slope” — which sounds like a magical place where deep sleep nurtures big decisions.

“The EEG spectral slope has only recently been considered as a factor in cognitive processes during sleep,” Lowe said.

“I find the link between the spectral slope steepness during sleep, aha moments after sleep and the downregulation of weights — which we identified as crucial for aha moments in our previous computational work — very exciting.”

Nicolas Schuck, a professor of cognitive neuroscience at Universität Hamburg, revealed to The Post how to get the best bang for your buck from a nap.

How long should naps be?

“The naps in our study were 20 minutes and the effect we found on insights was related to participants reaching ‘N2’ sleep stage,” he said.

“When someone is ready to fall asleep, they’ll reach N2 rather quickly, within about five minutes. But the big unknown is when someone will begin to fall asleep.”

As many of us know from experience, trying to take a 20-minute nap doesn’t always work, in which case, the benefits cannot be reaped. 

But, generally speaking, “naps less than 30 minutes can already have positive effects,” Schuck said.

Is there a good time to take them?

“We can’t say from our study, but most adults feel tired … in the early afternoon, which might increase the chance to reach sufficiently deep sleep,” he said.

Other experts have told The Post that 1 p.m. to 3 p.m. is the sweet spot for short-term shuteye.

Any ways to guarantee reaching the N2 sleep stage?

The short answer: not really.

“We can’t say from our study but other studies indicate that sleep quality and depth is influenced by many factors,” Schuck said.

“One is body temperature, and studies show that initiating sleep is easier during phases of lower core body temperature,” he continued. “So it is important that the room temperature is right, with typical recommendations around 65-68°F.  I am not aware whether someone has looked specifically at naps, though.”

He also recommends not napping for too long or waiting too late in the day, otherwise, your nap can sabotage your nighttime sleep.