Why do we need sleep?

Scientists at the University of Rochester have found one of the reasons we need sleep is because our brains can take that time to clean out the build-up of brain junk we accumulate during our waking hours.

When our brain cells go about their day to day business, they produce waste product, which is cleared out by the bodies lymphatic system by the brain has own garbage men called the microglia, who sweep the leftovers straight down the body for elimination.


As it turns out, the brain’s garbage men move twice as fast when you’re sleeping, because your neurons shrink by half, making the fluid channels wider.

Solve your problems whilst you sleep

So you’ve heard the saying “to sleep on a problem”?

Well funny enough according to research, while the garbage men are clearing things out it allows the brain to deal with some of our more complicated problems.

In 2012 a study was published in the Journal of Memory and Cognition by the department of Psychology at Lancaster University in England. This study looked at the effects of sleep on human problem solving ability.

The researchers found that sleep can help the brain to solve difficult problems. So the old adage of ‘sleep on it’ definitely seems to have merit.

It’s interesting though that the study showed that for simpler problems, sleep is no more useful than continuing to try to solve the problem, or just taking some time out.

Are there different ‘types’ of dreams?

Sleep may seem to be a passive and dormant state, but even though activity in the cortex – the surface of the brain – drops by about 40 per cent while we are in the first phases of sleep, the brain remains highly active in the last few hours before you wake up.

A typical night’s sleep comprises five different sleep cycles, each lasting about 90 minutes. The first four stages of each cycle are regarded as quiet sleep or non-rapid eye movement (NREM).

The final stage is denoted by rapid eye movement (REM), which is where dreaming typically happens and our creative problem-solving abilities are most active. Adults spend about 20% of their sleep in the REM stage, whereas babies can spend up to 50% of their sleep in this stage.

sleep cycle management_3

Dreams can bring a fresh approach to problem solving

Dreams are highly visual and often illogical in nature, which makes them ripe for the type of “out-of-the-box” thinking that some problem-solving requires, said Deirdre Barrett, a psychologist at Harvard University.

The Beatles’ ‘Yesterday’ – was reportedly written by Paul McCartney following a dream. McCartney was so impressed by this work that he subsequently had to be convinced that the melody was of his own creation.

So next time you wake up after a dream, don’t immediately jump out of bed as this is often when you can lose the dream content. If you don’t recall the dream immediately see if you feel a particular emotion.

By latching on to this often the whole dream will come flooding back! Then write it down in a journal next to your bed.

What is lucid dreaming?

A powerful way of solving a problem in your dreams is through what is known as ‘lucid’ dreaming, whereby you become aware you are dreaming within the dream and at which point you’re able to interact with it – becoming an active participant rather than an observer.

Director Christopher Nolan took the inspiration for his 2010 psychological thriller Inception from his own lucid dreams.

How to lucid dream

Psycho-Physiologist Stephen LaBerge recommends a technique called mnemonic induction of lucid dreams (MILD).

Wake up an hour earlier than usual and recall your last dream.

Before going back to sleep think: “The next time I dream, I want to remember I’m dreaming.” Lucid dreams occur most often in the morning just before awakening.

Research on sleep cycle management

Sleep on it, but only if it is difficult: Effects of sleep on problem solving

Read more from WatchFit Expert  Dean Griffiths

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