Hi, I'm John Green. Welcome to my salon. This is mental Floss on YouTube, and did you know that video games might be good practice for lucid dreaming?

According to studies conducted by Jayne Gackenbach, a psychologist at Grant MacEwan University in Canada, gamers spend so much time practicing virtual reality that they're more likely to be able to control actions in their dreams.

Plus, in a study she did in 2008 with about a hundred participants,
she found that gamers were less prone to nightmares because they were more willing to fight back during their scary dreams.

And that's the first of many facts about dreams that I'm gonna share with you today in this video brought to you by Geico.

It's worth noting before we start that scientists still don't know that much about dreams, so these are just some things that have been studied and observed. Alright let's get to it!

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(0:48) According to a 1966 study in which people reported on their dreams, dreams are primarily visual and auditory. Smell and taste sensations occur less than one percent of the time.

But interestingly a 2009 study from the European Sleep Research Society (1:01)found that presenting smells to a sleeping person could affect their dreams. Positive smells like roses produced positive dreams (1:08)and negatives smells like rotten eggs gave more negative dreams.

In the average lifetime a person will have over a hundred thousand dreams. That might include dozens of dreams in a single night, but we only spent about two hours each night dreaming.

Fifty percent of people report having had a recent pre-cognitive dream, or a dream that seems to tell the future. But most experts believe that this phenomenon is due to the law of large numbers.

Basically tons of stuff happens every single day so it's very probable that every once in a while, something that happens will have been recently dreamt about.

A famous pre-cognitive dream happened to Abraham Lincoln a few days before he was assassinated. According to his friend Ward Hill Lamon, Lincoln told a small group that he dreamed of a group of soldiers. He asked the group "Who died?" and a soldier responded: "The president. He was killed by an assassin".

But whether Lamon was telling the truth, well ... that's for you to decide. Also how often did Lincoln probably dream about getting assassinated? He was under constant threat of assassination. I shouldn't make jokes about your assassination Abe Lincoln. You're my favorite bobblehead on the entire wall.

Another famous dreamer was Dmitri Mendeleev, the inventor of the periodic table, who claimed that the idea came from a dream. He said: "I saw in a dream a table where all the elements fell into place as required. Awakening I immediately wrote it down on a piece of paper, only in one place did a correction later seem necessary."

I have dreams for my books like that all the time and then I wake up and I write down exactly with the dream told me to write down and then I read it like four hours later when I'm like properly awake and its awful.

People tend to remember more negative emotions than positive
ones in dreams. This phenomenon was observed by researcher Calvin S. Hall who monitored dream accounts for more than 50,000 college students over the course of forty years.

The most commonly reported feeling from dreams? Anxiety. I wasn't aware that you could feel something else from a dream. 

According to a 1996 study conducted by William Domhof, children between the ages of 9 and 11 only recall about 20 to 30 percent of their dreams. Adults, on the other hand, have a recall rate around 79 percent.

But according to dream researcher Jay Allan Hobson we forget about 95 percent of our dream so this is definitely something
that needs to be researched more as the so much sleep science. Generally the field of like dream studies sometimes suffers from a lack of intellectual rigor.

Humans dream during both REM sleep and non-REM sleep but babies are the champions of REM sleep, spending over half their sleep time in REM. Now we don't know if they're really dreaming all that time, but adults only spend about 20 to 25 percent of their sleep time in REM but we dream at least four to six times per night.

And although we think of them as little imagination factories, in fact children have fairly realistic dreams. According to one study about 29 percent of their dreams are realistic around 47 percent are realistic fiction and only 4 percent are purely fantastic, those are comparable with adult dreams.

Now is it realistic realistic fiction or purely fantastical when I dream that I am a banana on the space shuttle? Because I mean I think there are bananas on the space shuttle but I'm unlikely to become one of them.

Anyway, many people have reported that wearing a nicotine patch intensifies their dreams.

A lot of people wonder how blind people dream. Experts have observed that if a person was born blind or went blind at a young age, they typically only dream in smell, sound, taste, and touch, not in sight. But those who went blind later in life often do have visual dreams.

There's something known as hypnagogia or a wakeful dream. This is when someone transitioning from being awake to being asleep dreams, so during that time people technically dream while they're awake which could mean anything from experiencing weird visuals and sounds to hallucination.

The Hawaiian word for dream translates to soul sleep. This is because Hawaiians believe that people were able to communicate with ancestors and gods while they slept.

Ancient Mesopotamians and Egyptians also considered dreams to be very important. Both societies had dream interpreters who would tell the future based on a person's dreams, and in fact the Chester Beatty papyri are the manuscripts to contain the earliest known dream dictionary and it was written over three thousand years ago in ancient Egypt.

According to a 1996 study, between 60 and 75 percent of adults have recurring dreams and women are more likely to have them than men.

It might not feel like it but we dream in real time according to Doctor Rubin Naiman, a psychologist who studies sleep at the University of Arizona, dreams can last anywhere from a couple minutes to an hour.

Mammals and birds have REM sleep, so they probably dream but reptiles probably don't. But if reptiles don't dream does Medusa dream? That's presumably what she and the Flash are talking about.

According to a 2007 study conducted at the University of Montreal, new mothers are more likely to have nightmares than pregnant women or women with no children. In fact, three quarters of women who recently gave birth had nightmares about bad things that might happen to their babies.

When awakened while dreaming, people rend to report that their dreams contained vivid colors seventy percent of the time and vague color 13 percent of the time, but outside of scientific studies only 25 to 29 percent of people say that they dream in color. So many of us do dream in color but don't properly remember.

Interestingly, childhood exposure to black and white television affects whether people dream in color. A 2008 study revealed that people who are 25 years old or younger rarely report dreaming in black and white. People who are older than 55 though, say that they dream in black-and-white fairly often.

These findings were reversed in studies done in the forties, college students claimed they rarely dreamt in color, so scientists think that TV might be involved.

And finally I return to my salon to tell you that men dream about men more than women dream about men. According to studies, sixty-six percent of the characters in men's dreams are male, whereas the ratio of male to female characters in women's dreams is 50/50. And this phenomenon is true across all cultures that have been observed, so maybe it just says something about men.

Thanks for watching this episode of Mental_Floss here on YouTube which was made with the help of all these nice people and brought to you by our friends at Geico. So thanks very much, Geico. 

If you had any weird dreams of your own lately, feel free to share them in the comments because your friends and families don't
want to hear about them. There's nothing less interesting than other people's dreams. Anyway, as we say in my hometown don't forget to be awesome.