If the Donald Trump masks, maniacal clown costumes, and zombie Ken Bone suits don’t scare you this Halloween, then maybe you should try turning off the lights and catching some sleep. There’s no place quite as terrifying as the dark side of the human mind, where nightmares are spawned.
What produces these depraved nocturnal deliriums, and what purpose they serve, are questions that neuroscientists, shamans, and technicolor dreamcoat-wearers have attempted to answer since the dawn of man. And while the meanings of our nightmares may remain engulfed in shadowy mystery, we are at least beginning to understand why our hidden demons sometimes choose to visit us while we sleep.
What is a nightmare?
University of Colorado School of Medicine associate clinical professor James Pagel told IFLScience that “there’s actually a bunch of different types of frightening dreams occurring at all stages of sleep,” not all of which are classed as nightmares. Night terrors, for instance, tend to strike midway through the sleep cycle, during the deep sleep phase, and have no clear form or plot, but simply cause people to wake up with an intense and unexplainable feeling of fear.
Nightmares, on the other hand, are experienced during the rapid eye movement (REM) phase, which occurs at the end of the sleep cycle. According to Pagel, nightmares are simply “dreams with a frightening story,” and are extremely common, affecting almost everybody at some point in their lives – especially during childhood and adolescence.
Nightmares occur during REM sleep, which is the final stage of the sleep cycle. Minerva Studio/Shutterstock
According to one study, between 5 and 8 percent of adults have recurring nightmares, while between 20 and 39 percent of children under the age of 12 regularly find themselves plunged into the haunted house inside their minds after lights-out. In the majority of cases this is not a serious problem, as Pagel says that scary dreams are to be expected from time to time, particularly if we have experienced something a little unsettling during the day, like watching a horror movie.
Things can get a little problematic, however, if a person develops nightmare disorder, whereby frequent nightmares stop them from sleeping properly and start to cause them distress during waking hours.