In 1953, Nathaniel Kleitman and Eugene Aserinsky, pioneering sleep researchers at The University of Chicago, discovered REM sleep and connected it with dreaming activity after scrutinizing the twitching eyelids of sleeping study participants. While we still don't know exactly why we dream (though increasingly advanced theories abound), we've since learned a lot about the physiology, content and nature of our racing REM minds. Here are nine fascinating facts.
You. Me. We All Dream
Whether we recall our REM adventures or not. Just look at this 2015 study on people diagnosed with REM Behavior Disorder (RBD). People who claim they don't dream, research suggests, simply don't remember doing it. But, their failure of recollection has some neurological basis, as a 2014 study showed different REM activity in the brains of purported non-dreamers.
Watch Black and White TV, Dream in Black and White
Back in 1942, a study revealed that people thought they primarily dreamt in black and white. At the time, 71 percent of the 277 college sophomores who participated in the study said they rarely or never saw rainbow hues during their REM cycles. Researchers repeated the study in 2001, and only 18% of participants made the same black-and-white claims. Hmm. In 2008, UK scientists sought to understand why some dreams might play out in grayscale and learned that people who’d been exposed to black-and-white talkies as children were more likely to have similarly color-stripped dreams throughout their lives.
REM Dreams are More Aggressive
Dreaming doesn’t only take place during REM, but REM and Non-REM dreams appear to have qualitative differences. One study, for example, suggests that people are more likely to dream about friendly social interactions outside REM. Once that rapid eye movement begins, so does the beef.
Gun Users Experience Violent Dreams More Often
Does exposure to violence infiltrate the subconscious mind? Maybe, if there’s no screen involved. One study compared Canadian soldiers to fans of Call of Duty and other such virtual bloodbaths. It turned out that those accustomed to holding guns, rather than controllers, had more frequent violent dreams.
Women Report Having More Frequent Nightmares Than Men
Or so the reports would have us believe. And this gender binary begins around 10 years old, according to one study. Why? It’s speculated that members of the fairer sex generally have better dream recall and exhibit higher levels of neuroticism, a trait that corresponds to nightmare frequency.Female night owls, in particular, have a lot of nightmares, as compared to morning larks. The nightmare-owl link, one study showed, is most pronounced between the ages of 20 and 29. We say: Makes sense — Financial independence. Taxes. Slower metabolism. Bad hangovers. Yeah, adulthood is terrifying.
Expectant Moms Have Freakier Dreams
Compared to non-pregnant women, mothers-to-be report a considerably higher incidence of bad dreams, especially during the third trimester. They also get far shoddier sleep during the final gestational stretch, one study found, which may account for all those ‘mares. Across the board, however, all of our dreams contain more negative than positive emotions.
We Have the Ability to Observe What the Dreaming Mind Sees
It sounds straight out of SciFi, but it's strue. In 2013, scientists figured out that they can use fMRI to predict what people are visualizing in their dreams. It turns out that brain activity patterns correspond to the same mental images whether we’re awake or asleep. So, by observing brain activity of conscious people when they're thinking about, say, apples, scientists can work backwards, and figure out who’s lost in a Red Delicious fantasy. Neuroscience is so simple.
Smell Shapes Our Dreams
We rely on smoke alarms to alert us about fires because olfactory processing largely shuts down when we’re asleep. Weirdly enough, odors do appear to influence the emotional tone of our dreams, at least according to one 2008 study. German researchers found that dozers exposed to the scent of rotten eggs reported more negative dreams, whereas exposure to aromatic roses corresponded to sweeter dreams.