Hi, I'm Elliott and this is Mental Floss on YouTube. Today I'm going to talk about some misconceptions about sleep. 

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Misconception #1: The older you get the less sleep you need. So this is kinda complicated because everyone has different sleep requirements. According to the National Sleep Foundation, adults require an average of 7 to 8 hours of sleep every day. But how much a person requires depends on things like lifestyle and health. Still sleep shouldn't decrease over the course of a person's life. Older people don't require less sleep than younger adults. I personally require like 18 hours a day.

Misconception #2: Dreaming only happens during REM sleep. Most of your dreams do occur during REM sleep, but it's possible to dream during any of the other four stages of sleep. These dreams are typically less intense and vivid than dreams during REM sleep. By the way, you dream for about 2 hours every night. Think about that! That means everyday we're presented with intense movie length entertainment and we just sleep right through it every single time. It's ridiculous. 

Misconception #3: If you work out late at night, you won't be able to sleep. A study done in 2011 by the European Sleep Research Society examined sleep quality of subjects both after 35 minutes of exercise and after no exercise. They found no difference in sleep quality. A 2014 study done at Arizona State University in Phoenix tested this idea again. They polled 1000 adults about exercise and sleep habits. People who exercised in the morning were more likely to report getting better sleep, but the study did not find any compelling evidence that adults who exercised in the evening had poor sleep quality. 

Misconception #4: Counting sheep helps you fall asleep. A 2002 study conducted by scientists at Oxford University split insomniacs in to groups. The two groups that took the longest to fall asleep were made up of subjects who were told to count sheep or given no instructions whatsoever. The researchers found the subjects who fell asleep the quickest, were those in the group who were told to picture a relaxing place. Like a beach. Y'know, in Florida. With a nice margarita. And just a sunset. 

Misconception #5: Your brain rests while you sleep. People believed this until the 50s when researchers discovered that brains are actually really active during sleep. In fact, according to the Division of Sleep Medicine at Harvard Medical School, during some stages of sleep the brain is just as active as when we are fully awake. Unlike you're brain though, your body does rest while you sleep. Sleep is the best time for your body to build bone and muscle and regenerate tissue. It's got a lot going on guys.

Misconception #6: Your body will get used to less sleep over time. People really started to wonder this when Margaret Thatcher told the world that she slept a mere 4 hours every night. In reality it's not possible to adjust to less sleep. Some side effects of not getting enough sleep are distress and less concentration. Plus, not getting enough sleep over time puts a person at an increased risk for serious side effects like diabetes and cardiovascular disease. 

Misconception #7: If you die in your dream, you die in real life. No. Guys this is real life, okay? Not a Nightmare on Elm Street. At least I hope so. Plenty of people have died in their dreams, then woken up and told people about it. And then all those people have pretended to be interested. 

Misconception #8: It's best to just lie in bed and wait for sleep to come. If you can't sleep many experts agree that the best course of action is to get out of bed. After 20 minutes of sleeplessness you should get up and do a relaxing activity like reading until you get tired again. Avoid your phone, computer, and TV though. The light from those devices will just make the problem way worse.

Misconception #9: Yawning equals sleepy. Question *yawns* did you yawn when I just did? Yawns are contagious even if you're not tired. Plus, I was just able to make myself yawn despite not being tired at all. Even though I faked it. There are plenty of different reasons for yawning besides just being tired. In fact, most species yawn and some use it to threaten others. Other species use it to seduce a mate. Interestingly a study done at Drexel University found that those who were more susceptible to contagious yawns scored high in empathy on a personality test. The same researcher then had subjects yawn while they were in MRI machines. It turned out that yawning lit up the brain regions that were associated with empathy. Which are some where around here.

Misconception #10: You should never wake a sleepwalker. Many people believe that waking a sleepwalker will do them serious harm. Some even claim that a sleepwalker will have a heart attack upon being awoken. It's more likely that you'll just freak them out. But sleepwalkers shouldn't just be abandoned because they can get themselves in some pretty serious danger. In 2005 a sleepwalking 15 year old had to be rescued after she managed to climb up a crane that was 130 feet tall. Experts recommend that rather than abruptly waking a sleepwalker, you should just lead them back to their bed. As long as that doesn't involve climbing out a 130 foot crane. 

Thank you for watching Misconceptions on Mental Floss on YouTube. That is made with the help of all these wonderful people. If you have a topic for an upcoming Misconceptions episode that you would like to see, leave it in the comments and I will see you next week.