In a study just out, researchers at the University of California San Diego tested whether “incubating” a problem allowed a flash of insight, and found it did when people entered a type of sleep known as REM.

When we sleep we pass through different ‘stages’ of sleep that are associated with different types of brain activity. REM sleep is the stage that we know as dreaming. It is detectable by electrical activity in the brain that looks much like the waking state, and by rapid eye movements – hence ‘REM’.

Volunteers who had entered REM or rapid eye movement sleep in this Proceedings of the National Academy of Sciences (PNAS) study were then better able to solve a new problem that required lateral thinking. Lateral thinking involves looking at a problem from unconventional angles in order to solve it, making connections that are not obvious. It involves thinking ‘around’ a problem rather than tackling it head-on.

On the morning of the test day, 77 volunteers were given difficult creative problems to solve. After trying to solve them, they were asked to mull over the problem until the afternoon – either by resting but staying awake, or by taking a nap. The naps were monitored, to check whether or not the participants entered REM sleep.

Compared with quiet rest and non-REM sleep, REM sleep increased the chances of success on the problem-solving task – improving creative problem solving ability by close to 40%.

The results suggest a very special role for dreaming in problem solving. It is not just sleep itself, or the passage of time, that is important for the problem solving, but whether REM sleep has occurred.

The researchers believe that dreaming “creates a richer network of associations for future use”.

Other studies indicate it does more than this: it is actually able to help in unraveling logical connections through unconscious reasoning – an important aspect of fluid intelligence – our on the spot problem solving ability.

Dreaming improves finding logical patterns and seeing ‘the big picture’

A study in 2007 – also published in the PNAS – led by Matthew Walker and colleagues demonstrated that solving fluid intelligence type questions, involving abstracting logical relations, and seeing ‘the big picture’ in terms of underlying patterns, was much improved by sleep.

For instance, if a person learns that A is greater than B and B is greater than C, then she knows those two facts. But embedded within those is a third fact – A is greater than C. This can be deduced by an inference. It is this kind of logical relationship finding that dreaming can also enhance. In other words, dreaming helps with fluid intelligence problem solving.

Applications

When you are working on a complex problem in your life, there are many of these types of logical connections that aren’t at first obvious. First set yourself the clear intention of figuring the problem out. Really commit to understanding your situation more clearly and deeply – seeing the big picture and implications you hadn’t noticed. With this commitment in place, you can be assured that just sleeping on it will help substantially.