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. 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. 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. Night owls are more likely than their early-bird counterparts to experience 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.
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." 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.
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. The 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.