WHY SLEEPING ON A PROBLEM IS THE ANSWER

SOME of the most revolutionary leaps forward in human progress have come about because of dreams. In the field of science, the Russian chemist Dmitri Mendeleev spent years trying to work out how all the known elements in the universe should be ordered.

That was until dreaming provided him with the answer one night. When he woke up he wrote it down, giving us the periodic table of elements.

In my own field of neuroscience, it was a dream that led Otto Loewi to realise that nerve cells could signal to each other using chemicals, which meant they could communicate even when they were not touching.

It won Loewi a Nobel Prize.

We also know of precious artistic gifts that have arisen from dreams. The songs Yesterday and Let It Be both came to Paul McCartney in his sleep.

However, Keith Richards of The Rolling Stones has arguably the best sleepinspired story, which gave rise to the opening riff of their song Satisfaction.

Richards would routinely keep a guitar and tape recorder at his bedside to record ideas that would come to him in the night.

He describes the following experience from May 7, 1965, after having returned to his hotel room in Clearwater, Florida, following a performance that evening.

‘I go to bed as usual with my guitar, and I wake up the next morning, and I see that the tape is run to the very end. And I think, “Well, I didn’t do anything. Maybe I hit a button when I was asleep”. So I put it back to the beginning and pushed play and there, in some sort of ghostly version, is [the opening lines to Satisfaction].

‘It was a whole verse of it. And after that, there’s 40 minutes of me snoring. But there’s the song in its embryo, and I actually dreamt the damned thing.’

More than simply melding information together in creative ways, REM (or dreaming) sleep can take things a step further. Think of an experienced doctor who is intuitively able to diagnose a patient from observing many subtle symptoms.

While this kind of skill comes after years of hard-earned experience, it is also the very same assessment of information that REM sleep accomplishes each night.

Perhaps the most striking proof of sleep-inspired insight, and one I most frequently describe when giving talks to companies to help them prioritise employee sleep, comes from a study conducted by Dr Ullrich Wagner at the University of Lubeck, Germany.

Participants had to work through hundreds of laborious number problems, almost like having to do long division for an hour or more. What the researchers did not mention was the existence of a hidden rule, or shortcut, common across all of the problems. This would enable many more problems to be solved in a far shorter time.

These participants were given another set of mindnumbing problems 12 hours later.

Some of them spent that 12hour time delay awake, while for others, that time window included a full eight-hour night of sleep.

After their 12 hours spent awake, a rather paltry 20 per cent of the participants were able to identify the shortcut.

Things were very different for those participants who had obtained a full night of sleep: almost 60 per cent had the ‘ahha!’ moment of spotting the hidden cheat — which is a threefold difference in creative problem-solving. This insight was afforded by sleep!

Little wonder, then, that you have never been told to ‘stay awake on a problem’. Instead, you are instructed to ‘sleep on it’.

Interestingly, this phrase, or something close to it, exists in most languages (from the French dormir sur un probleme, to the Swahili kulala juu ya tatizo), indicating that the problem-solving benefit of dream sleep is universal and common across the globe.