By Jeanna Bryner, LiveScience Managing Editor | LiveScience.com – Sat, Apr 28, 2012
When your head hits the pillow, for many it's lights out for the
conscious part of you. But the cells firing in your brain are very much
awake, sparking enough energy to produce the sometimes vivid and
sometimes downright haunted dreams that take place during the
rapid-eye-movement stage of your sleep.
Why do some people have nightmares while others really spend their nights in bliss? Like sleep,
dreams are mysterious phenomena. But as scientists are able to probe deeper into our minds, they are finding some of those answers.
Here's some of what we know about what goes on in dreamland.
1. Violent dreams can be a warning sign
As if nightmares weren't bad enough,
a rare sleep disorder
— called REM sleep behavior disorder — causes people to act out their
dreams, sometimes with violent thrashes, kicks and screams. Such violent
dreams may be an early sign of brain disorders down the line, including
Parkinson's disease and dementia, according to research published
online July 28, 2010, in the journal Neurology. The results suggest the
incipient stages of these
neurodegenerative disorders might begin decades before a person, or doctor, knows it.
2. Night owls have more nightmares
Staying up late has its perks, but whimsical dreaming is not one of
them. Research published in 2011 in the journal Sleep and Biological
Rhythms, revealed that
night owls are more likely than their early-bird counterparts to experience
nightmares.
In the study 264 university students rated how often they experienced
nightmares on a scale from 0 to 4, never to always, respectively. The
stay-up-late types scored, on average, a 2.10, compared with the morning
types who averaged a 1.23. The researchers said the difference was a
significant one, however, they aren’t sure what's causing a link between
sleep habits and nightmares. Among their ideas is the stress hormone
cortisol, which peaks in the morning right before we wake up, a time
when people are more prone to be in REM, or dream, sleep. If you’re
still sleeping at that time, the cortisol rise could trigger vivid
dreams or nightmares, the researchers speculate. [
Top 10 Spooky Sleep Disorders]
3. Men dream about sex
As in their wake hours,
men also dream about sex
more than women do. And comparing notes in the morning may not be a
turn-on for either guys or gals, as women are more likely to have
experienced nightmares, suggests doctoral research reported in 2009 by
psychologist Jennie Parker of the University of the West of England.
She found women's dreams/nightmares could be grouped into three
categories: fearful dreams (being chased or having their life
threatened); dreams involving the loss of a loved one; or confused
dreams.
4. You can control your dreams
If you're interested in lucid dreaming, you may want to take up video
gaming. The link? Both represent alternate realities, said Jayne
Gackenbach, a psychologist at Grant MacEwan University in Canada.
"If you're spending hours a day in a virtual reality, if nothing else
it's practice," Gackenbach told LiveScience in 2010. "Gamers are used to
controlling their game environments, so that can translate into
dreams." Her past research has shown that people who frequently play
video games are more likely than non-gamers
to have lucid dreams
where they view themselves from outside their bodies; they were also
better able to influence their dream worlds, as if controlling a
video-game character.
That level of control may also help gamers turn a bloodcurdling
nightmare into a carefree dream, she found in a 2008 study. This ability
could help war veterans suffering from post-traumatic stress disorder
(PTSD), Gackenbach reasoned.
5. Why we dream
Scientists have long wondered
why we dream,
with answers ranging from Sigmund Freud's idea that dreams fulfill our
wishes to the speculation that these wistful journeys are just a side
effect of rapid-eye-movement (REM) sleep. Turns out, at least part of
the reason may be critical thinking, suggests Harvard psychologist
Deirdre Barrett who presented her theory in 2010 at the Association for
Psychological Science meeting in Boston.
Her research revealed that our slumbering hours may help us solve
puzzles that have plagued us during daylight hours. The visual and often
illogical aspects of dreams make them perfect for the out-of-the-box
thinking that is necessary to solve some problems, she speculates.
So while dreams may have originally evolved for another purpose, they
have likely been refined over time for multiple tasks, including helping
the brain reboot and helping us solve problems, she said.