Why some people have nightmares while others spend the night in absolute happiness?

Here you have some of the things we know about what happens in dreams.

Violent dreams may be a warning sign

As if the nightmares were not unpleasant enough, a rare sleep disorder, disorder known as REM sleep behavior, makes people act out their dreams with violent blows, kicks and screams. These violent dreams can be an early sign of brain disorders, including Parkinson's disease and dementia, according to a study published on July 28, 2010, in the journal Neurology.

The results suggest that the early stages of these neurodegenerative disorders may start decades before the person or the doctor realize.

Night owls have more nightmares

Stay up very late has its advantages, but having strange dreams is not one of them. Research published in 2011 in the journal Sleep, biological rhythms, found that night owls are more likely than early birds to have nightmares.

Possible explanations for this phenomenon is the stress hormone called cortisol, which has its peak in the morning just before waking, when people are more likely to be in REM sleep. If you are still sleeping at that time, increased cortisol could trigger strange dreams or nightmares, but this explanation is nothing more than mere speculation.

Men dream about sex

Just as when awake, men dream about sex more than women.

Actually the dreams of women, according to researcher Jennie Parker of the University of the West of England, can be grouped into three simple categories: dreams of fear (persecution or have life-threatening), dreams that involve loss of a loved one or confused dreams.

You can control your dreams

Jayne Gackenbach, a psychologist at Grant MacEwan University in Canada. has shown that people who frequently play video games are more likely than non-players to have lucid dreams in which are visible from outside the body and are also better able to control their dream worlds, as if it were a video game.

That level of control can also help players to make a chilling nightmare in a pleasant dream. This capability could help people suffering from posttraumatic stress disorder (PTSD).

Why do we dream?

Scientists have always wondered why we dream, with responses ranging from the idea of ​​Sigmund Freud in which dreams fulfill our desires, to speculation that these "magical trip" are just a side effect of rapid movement eyes (REM).

Deirdre Barrett, Harvard psychologist, says that the sleeping hours can help us solve the problems we have been asking all day. The visual aspects and illogical dreams often make them perfect to get a view "from outside" necessary to solve some problems.

So while dreams may have come originally for some other purpose, probably have been refined over time to multiple tasks such as helping to "reset" the brain or solve problems.