Skip to main content
Open this photo in gallery:

It is socially acceptable to talk about insomnia and sleepless nights, but we are less likely to discuss instances of Parasomnia, sleep disorders that involve involuntary movement or hallucinations.yanyong/iStockPhoto / Getty Images

Alice Vernon is the author of Night Terrors: Troubled Sleep and the Stories We Tell About It.

How did you sleep last night?

When asked this question, our automatic response is usually to confirm or deny that we did, in fact, sleep. We might say we slept like a log, long and deep, or that it took us a while to fall asleep, we tossed and turned, or some rude intrusion such as a fire alarm or a crying baby woke us up. There is so much more to this question, and so many ways to respond to it, but we always seem to play it safe. We’re never completely honest.

While it is socially acceptable, even encouraged, to talk about insomnia and sleepless nights, our quality of sleep also involves a stranger group of phenomena that we rarely admit to experiencing: parasomnias. Already the name conjures up the association to paranormal, to spirits, ghosts and monsters. This is part of the problem, perhaps.

Parasomnias are sleep disorders that involve involuntary movement or hallucinations. Among them are fairly well-known conditions such as sleepwalking and night terrors, but there’s also sleep paralysis – an intensely frightening hallucination of being pinned down or choked by a monstrous figure – and hypnopompic hallucinations, when you wake into a peculiar half-dreaming state that produces delusions and the imagined sight of spiders, snakes and other macabre objects in your bedroom. While they can sometimes be a symptom of, or a precursor to, disease, they can also occur in healthy individuals for no apparent reason. They’re far more common than we think, too. One study found that around 70 per cent of us will experience one or more of these phenomena in our lifetime, but when was the last time you heard someone mention their experiences, or even talked about your own?

For something that affects the vast majority of us, it seems odd that we wouldn’t talk about parasomnias to the extent we talk about insomnia or an amusing dream we had. This is, perhaps, because of the cultural stigma that has surrounded these sleep disorders for hundreds of years.

Take sleep paralysis, for example. When we dream, our muscles become paralyzed so that we don’t “act out” whatever we dream our arms and legs are doing. It’s a perfectly natural part of sleep. However, sometimes we wake up before that paralysis has worn off, yet our brain remains partly in the dreaming state. Because we can’t move, we come up with a reason as to why, and that reason manifests in a wholly realistic hallucination. This has had many names in the past, but most of them had to do with superstitious beliefs in witches and demons. An early name was mara, from which we derive “night-mare” – a term that now means “bad dream” but used to refer to sleep paralysis specifically in the form of a possessed horse, a mare, that would trample a sleeper’s chest. Other terms included being “hag-ridden” or “wizard-pressing,” or being attacked by the demonic goblin known as the incubus.

By the 16th century, some natural philosophers argued that sleep paralysis wasn’t caused by magic and malevolent hags, but by overeating and subsequent indigestion. Reginald Scot, in his 1584 treatise The Discoverie of Witchcraft, calls it a “bodilie disease.” Yet, more than one hundred years later in Salem, Mass., Bridget Bishop was executed for witchcraft after being accused by Richard Coman of coming into his bedroom while he slept, paralyzing him, and trying to choke the life out of him. Coman describes sleep paralysis, and Bishop was killed for it.

While we may not have the same panic over witchcraft, there is evidence to suggest that sleep paralysis still causes mistaken beliefs in otherworldly forces. One of the key characteristics of sleep paralysis is the way it often ends: From the sensation of being crushed comes a sudden feeling of weightlessness, of floating up toward the ceiling or back down onto the bed. Many reports of alien abduction over the past couple of decades feature this telltale sign, and seem to be the 21st-century equivalent of witchcraft superstition when it comes to spooky sleep experiences.

For most of my life, I’ve experienced parasomnias on a daily basis. When I was a child, I would sleepwalk through the house and have eerie conversations with myself or my parents. As an adult, my sleep has become like something from an Edgar Allan Poe story. I wake up to find shadowy figures looming over me, or I hallucinate large spiders (my biggest phobia) scuttling across my bedsheets. Worst of all, I occasionally experience sleep paralysis. It’s not usually a person I hallucinate, but lots of hands. I can feel the smooth, warm skin vividly against my own as disembodied fingers poke and grasp at me. Most often, they clutch my neck or my ankles, squeezing me in a relentless grip.

For a long time, I didn’t tell anyone about what happened to me in my sleep. There were occasions, particularly when I had several troubled nights in a row, that made me wonder if there was something morbidly wrong with me. With a preoccupation with sleep in the back of my mind, I started my PhD to investigate representations of insomnia in literature. It was only by doing research that I began to see descriptions of parasomnias – things that I had suffered with for many years.

Slowly, I began to mention these experiences to friends, colleagues and even my students. It astounded me when people responded with their own stories of troubled sleep. This was when I began to write my book, Night Terrors. I delved into the archives, finding anecdotes from hundreds of years ago from normal people describing very similar things to what I had seen or felt. Yes, there were those for whom parasomnias were cemented in the realm of the supernatural, but for most people it was a curiosity, something interesting that had happened to them and nothing more.

And there were writers, too, such as Bram Stoker, Robert Louis Stevenson and Shirley Jackson, who embraced troubled sleep as a bountiful source of inspiration for their work. Jackson, in particular, was equally delighted and horrified to find she had scribbled some notes in her sleep for a book that would become one of her most iconic: The Haunting of Hill House. Not only was I now hearing reports from people around me, but in the research I was conducting I could chart stories of parasomnias back as far as Classical Antiquity. Here was proof that I wasn’t so weird after all.

What began as a somewhat tentative look at my own sleep became a mission to encourage people to talk about their disordered sleep much more openly. The more we talk about our nocturnal wanders through the house, our Gothic hallucinations and our experiences with the mara of sleep paralysis, the more normal they will seem. I think parasomnias by their nature will always have supernatural associations, and will always be an easy trope to include in horror stories, but we need to realize that they are incredibly natural, too. We need to speak about parasomnias with the same ease with which we talk about insomnia and sleeplessness, and in doing so we might help to chase some of the ghosts away.

Now, when someone asks me how I slept, I tell the truth. I tell them I slept strangely.

Interact with The Globe