Have you ever gone to sleep pondering over a problem you just can’t solve? And when you wake up, you mysteriously feel that you have the answer?
And when you’re worried about life’s many problems, do they always seem a little easier to cope with after a good night’s sleep?
I know from personal experience that this magical effect can sometimes happen just when you most need it. But is there any scientific evidence that sleeping on a problem really helps?
What does research tell us?
1. Maths tests easier after sleeping
Back in 2004, scientists at the University of Luebeck in Germany gave the same maths test to a group of sleep-deprived people and a group who had eight hours of sleep.
Those with eight hours of sleep were three times more likely to figure out a hidden rule for converting the numbers into the right answer. Though how much of this was due to being less tired or the brain working on the problem whilst asleep isn’t clear.
2. Solving word problems
In 2012, researchers at Lancaster University in England looked at the effects of sleep on people’s problem-solving ability.
They split 61 people into 3 groups and gave everybody the same problems of verbal insight to solve. Some of the problems were easy and some more difficult.
Each group had to try and solve the problems they first struggled with after different time gaps. The gaps each group had were:
- Group one – slept and then had a second attempt.
- Group two – stayed awake, but had a break before trying again.
- Group three – had to attempt the problems again straight away.
The researchers found two very interesting results:
- The group who slept solved more of the difficult problems.
- There was no significant difference between the problem-solving ability of any group for the easy problems.
Accordingly, the researchers argue that their study illustrates that sleep can help the brain to solve difficult problems.
It’s interesting though that their study shows that for simpler problems, sleep is no more useful than continuing to try to solve the problem, or just taking some time out.
How your brain solves problems while you sleep
The Lancaster University team also provide some insights into how the problem solving works.
Your brain holds much more information than you can immediately recall. A classic example of this is remembering names. Have you ever struggled to remember someone’s name, only for it to pop into your head later?
The researchers suggest that sleep allows you to access the vast amount of knowledge in your brain that doesn’t immediately come to mind.
This is known as ‘spreading activation’, which allows your brain to seek other associations in your brain which might help solve the problem.
The interplay of REM and non-REM sleep
In 2018, Penny Lewis et al. from Cardiff University proposed a theory that both the REM and non-REM stage are important in problem solving.
They suggest that the memory replay in non-REM sleep works in harmony with the “high excitation, plasticity, and connectivity of REM sleep” to solve complex problems.
Can sleep help you be more creative?
The Cardiff team state that “It is commonly accepted that sleep promotes creative problem-solving”.
However, there appears to be less specific research to identify if sleep can boost creativity in all its forms. Equally, there are stories of artists, musicians and scientists waking up with ideas that appeared to them in their sleep.
- Russian chemist Dmitri Mendeleev established the periodic table of elements after sleeping.
- Paul McCartney from the Beetles says he came up with the tune for the song “Yesterday” in a dream.
- Robert Louis Stephenson dreamed up the plot to the Strange Case of Dr. Jekyll and Mr. Hyde.
Salvador Dalí capturing creativity
One of the more bizarre stories is about the famous surrealist painter Salvador Dalí. He was fascinated with the images which can come to you as you transition between sleeping and waking.
These images, known as sleep hallucinations, can occur when falling asleep or waking up, and are often very vivid, colorful and bizarre.
According to creativity post, Dalí tried to capture these moments by falling asleep sitting up, holding a spoon over a tin plate.
He would then relax and start to fall asleep. As he did so the spoon would drop and clang on the plate, immediately waking him up to capture the surreal images.
Can insomnia help creativity?
There are some who have a totally different view and argue that a lack of sleep might help creativity.
For example, the composer Marcel Proust wrote most of his À la recherche du temps perdu (In Search of Lost Time) while staying awake in the night due to a chronic illness.
And according to a piece in the Guardian, the musician Matt Berry explains how he wrote his new album during nocturnal sessions whilst suffering from insomnia. Dave Bayley of the Glass Animals, apparently also found his music went hand in hand with insomnia.
However, there appears to be little scientific evidence to support the suggestion that insomnia has a direct influence on creativity.
Can you use dreams to help you solve problems or be creative?
There are some who argue that you can influence your dreams to help you solve a problem or be more creative.
But there are others who argue that you can’t control your dreams in this fashion. There’s also a shortage of robust and meaningful research to support either view.
Let’s take a look at why they think this.
Dreams can help
Deirdre Barrett is a psychologist at the Harvard Medical School and world-renowned dream specialist. In her book, The Committee of Sleep, she gives many anecdotal examples of how some of the most creative people describe using their dreams to help creative problem solving. She defines the process as ‘dream incubation’.
Dreams can’t help
In 2004, a report by G. William Domhoff, a research professor in psychology and sociology at the University of California, Santa Cruz, stated:
When all is said and done, there is only occasional anecdotal evidence for the idea that recalled dreams have any role in solving or detecting problems. This evidence is not impressive when it is arrayed against the small percentage of dreams that are recalled and the even smaller percentage of recalled dreams that might be construed as having a solution to a problem.
A technique for using your dreams to solve problems
Even though there’s no clear evidence either way as to whether dreams can be harnessed in this way, it might be interesting to try.
Deirdre Barrett describes the following technique:
- Write down the problem in a brief sentence and place it by your bed.
- Review the problem for a few minutes just before going to bed.
- Once in bed, visualize the problem as a concrete image if possible. Visualize yourself dreaming about the problem, waking up and writing about it.
- Tell yourself you want to dream about the problem as you drift off to sleep.
- Keep a pen and paper on the bedside table.
- Arrange objects connected to the problem on your table or write about it on a poster.
- When you wake up, lie quietly before getting out of bed. Note whether there’s any trace of a recalled dream, and invite more of the dream to return if possible.
- Write it down.
The suggestion of keeping a notepad by the side of the bed isn’t unusual. It’s useful to write down worries or a ‘to do’ list before you go to bed. And some people also like to keep a drean diary.
Can sleep help with life’s many problems?
The research talks about how sleep might help with reasoning problems. But what about our everyday worries and problems?
These are often very complex and emotional. So what if this research was applicable to important decisions that need to be made, or relationships that need to be worked on?
There isn’t much research about this yet, unfortunately. But on a personal level, I’ve fairly sure I’m better at making balanced decisions after a good night’s sleep.
If something upsets me, I almost always feel a bit better about it in the morning. And that’s a good reason to leave any letters, emails or decisions started when feeling angry, frustrated or upset as a draft until the morning!
Do you find problems seem easier in the morning? Have you ever had a moment of inspiration arrive in a dream? Let me know below.