Scientists have known for a long time that sleep is important for learning. Sleep helps us form long-term memories and be more creative. A good night’s sleep after you’ve learned something new will help you commit your new knowledge to memory. Do you have a problem that you can’t solve? Sleep on it and after you awaken, you’re likely to come up with a creative solution.

Researchers at the Federal University of Paraná in Brazil wanted to find out more about how sleep helps with problem solving. To do this, they studied how people solve problems they encounter in video games.

Photo by Gamesingear, Creative Commons License, Wikimedia CommonsThe researchers taught 29 female university students how to play the game Speedy Eggbert Mania®. Each student then played the game, progressing from level to level until she encountered a problem she couldn’t solve. Once the student reached a level she couldn’t clear within ten minutes, she ate a light meal and then either took a nap or stayed awake quietly for 90 minutes, the length of the average sleep cycle. 14 students napped while 15 remained awake.

All of the students had EEGs recording their sleep/wake state.

Later in the day, each student was tested at the level she was unable to finish earlier.

Of students who napped, 12 (86%) were able to solve the problem they had encountered earlier and get to the next level within 10 minutes.

Only seven of the students who remained awake – less than half – were able to succeed.

Sleep seemed to enhance the napping students’ problem-solving abilities.

The fact that most of the non-napping students weren’t able to solve the problems they encountered when playing showed that resting by itself wasn’t enough. After all, those students had 90 minutes to relax. Sleep was essential.

Interestingly, the students who slept didn’t spend much time in REM sleep. Despite the fact that earlier studies have shown that REM sleep is associated with creativity and problem solving, students who achieved REM sleep were no more likely to solve their problems than students who also napped but never entered REM sleep. The researchers think this means that that slow-wave, non-NREM sleep could be necessary for processing memories that involve spatial and visual information, the kind of information you encounter when playing a video game.

This research won’t just help you get high scores on video games. According to the researchers, their study might mean that sleep helps you understand a problem better, and that can help you devise a strategy for solving it.

It could mean that the purpose of sleep is to help us survive by making it easier for us to solve problems we encounter in our daily lives.

You can read the full study at PLOSONE.


Find out more about dreams and sleep by learning these 11 fascinating facts.

1. People everywhere share the same dreams.

The American psychologist Calvin Hall studied dream reports of more than 50,000 people from all over the world, and found that while their dreams reveal some cultural differences, they tend to be very similar.

2.  A Greek man named Artemidorus wrote the first dream dictionary.

His work, the Oneirocritica, contains a dream dictionary and instructions for interpreting dreams. Modern dream dictionaries still use some of his interpretations.

Śpiący Staś, by Stanisław Wyspiański

Śpiący Staś, by Stanisław Wyspiański

Artemidorus thought your dreams are your mind’s way of interpreting images that your soul creates when it moves.

3. Not all ancient people thought that gods or spirits created dreams.

The ancient Greeks thought that dreams originated from within the dreamer.

Hippocrates, the ancient Greek physician.  thought that that interpreting a patient’s dreams could help you understand the physical cause of their suffering.

4. Sigmund Freud was the first person to say that the unconscious affects dreams.

Freud thought that you could solve problems in waking life by understanding your dreams, which would help you understand your unconscious. He developed the method of interpreting dreams by free association.

5. Rapid eye movement (REM) sleep is the stage of sleep most commonly associated with dreaming. However, you can dream during all stages of sleep.

Dreams that occur during REM sleep tend to be more vivid than dreams that occur during other stages of sleep. However, that isn’t a universal rule. You can have vivid dreams during non-REM (NREM)

Although dreaming and REM sleep often take place at the same time, they originate in different areas of brain. Some people with brain damage dream but don’t have REM sleep, while others have REM sleep but don’t dream.

6. REM sleep is necessary for life.

Rats that are deprived of REM sleep, but still allowed to experience the other stages of sleep, will die in about five weeks.

7. During a lucid dream, you’re awake and asleep at the same time.

Parts of your brain that are normally active only when your awake are still active during a lucid dream. These include regions of the brain that you use to think about yourself and to think about thinking.

8. Scientists can prove if someone is having a lucid dream.

A scientist can ask a lucid dreamer in a sleep laboratory to move their eyes in a dream or to dream about writing something. If they dream about moving their eyes, their eyes will move. If they dream about writing, their hand muscles will twitch.

The dreamer is hooked up to an EEG, so the scientist knows that the dreamer is in REM sleep and isn’t faking.

9. “Alien abductions” are probably cases of sleep paralysis.

During REM sleep, most of your body is paralyzed.  Sleep paralysis occurs when you become conscious but haven’t fully awoken from REM sleep. You are aware of your surroundings, but you still can’t move.

Because your breathing changes naturally during REM sleep, when you have an attack of sleep paralysis, you may feel like you are suffocating. You may think that someone is choking you or sitting on your chest, crushing it so you can’t breathe.

The part of your brain that makes you feel afraid can become very active during sleep paralysis. This can make you feel terrified. You may hallucinate that an evil monster, demon or alien is in the room watching you or that they are trying to hurt you.

10. You can make someone have an out of body experience by stimulating a certain part of the brain.

Doctors have accidently caused people to have out of body experiences by stimulating a region of the brain called the temporoparietal junction.

11. People who have trouble falling asleep or waking up on time could have circadian rhythm disorders.

If you have a circadian rhythm disorder, your body clock is different from that of most people. Your body wants to go to sleep when everyone else says you’re supposed to be awake, and it wants to stay awake when people tell you that you should be asleep.

You may think you have insomnia, or other people may think you’re lazy, but if you let yourself sleep when your body wants and stay awake when your body wants, you’ll have just as much energy and be as productive as anyone else is.