Imagine a world without the movie The Terminator, the novel Frankenstein, or the song (I Can’t Get No) Satisfaction. Thanks to hypnagogic dreams, that nightmare Earth does not exist.
Science has been investigating hypnagogia for 25 centuries now. You’d think we’d know more about these dreams than we do, but here are the basics:
Hypnagogic dreams happen in the transition between wakefulness and deep sleep. To the dreamer, they feel like real events. People experiencing them have sensations like touching an object, or hearing loud noises, or flying.
These illusions can be weird or scary. Sleep paralysis hallucinations occur when the dreamer sees or hears something dangerous, but they can’t move or awake from the dream. Sometimes the dream is so scary, it’s hard to get back to sleep.
But these dreams are also the basis for creativity and problem solving—like the ideas for movies, novels, and songs.
The Story of One Famous Hypnagogic Dream
A 19-year-old named Mary Godwin was staying at a country house with some friends. They didn’t have much to do because it rained every day—so one member of the group suggested that everyone write a ghost story to tell.
But Mary couldn’t think of anything. Not that day, or the day after, or the day after that. It was getting embarrassing for her.
Then, one night, she had what she called a “waking dream”—undoubtedly, what scientists today call a hypnagogic dream.
I saw the pale student of unhallowed arts kneeling beside the thing he had put together. I saw the hideous phantasm of a man stretched out, and then, on the working of some powerful engine, show signs of life, and stir with an uneasy, half vital motion.
Mary Godwin—later Mary Shelley—turned her hypnagogic dream into one of the world’s great novels: “Frankenstein”.
How Common Is Hypnagogia?
Shelley isn’t alone. Paul McCartney has said he dreamed the melody to “Yesterday”. Salvador Dali used hypnagogic dreams as a source of inspiration. He even gave fellow creatives specifics on how to have them, which involve sitting in an uncomfortable armchair while holding a heavy key.
Even scary dreams can be productive. Elias Howe, the inventor of the sewing machine, said he realized a critical innovation while dreaming that cannibals were about to cook him.
Students of religious visions have suggested that the hypnagogic state is the ideal time to receive divine instruction. Hypnagogic dreams, or something like them, were described as far back as Aristotle in the fourth century B.C., with the first definitive case study recorded by a Dutch physician in 1664.
According to the medical journal “The Lancet”, 21st-century studies indicate that hypnagogic hallucinations are quite frequent. Between 39% to 85% of people experience hypnagogia, according to estimates.
The Three Common Types of Hypnagogic Nightmares
A 50-year-old woman in the Netherlands described a frightening dream to her physician in 1664.
She believed the devil lay upon her and held her down, sometimes that she was choked by a great dog or thief lying upon her breast, so that she could hardly speak or breathe, and when she endeavored to throw off the burden, she was not able to stir her members.
Now, 350 years later, science can classify her dream as an Incubus dream—one of the three common types of hypnagogic nightmares.
Incubus dreams involve pressure on the chest and breathing difficulties, often caused by some imagined being. The 1782 painting “The Nightmare”, by Swiss artist Henry Fuseli, seems to depict such a dream. Dream researchers think that neurons which perceive breathing may be acted on in this dream. We aren’t actually having trouble breathing, but our brain thinks we are.
Cultures around the world have named these types of dreams. According to a 1999 New York Times article:
The Chinese called it “gui ya,” or ghost pressure, and believed that a ghost sat on and assaulted sleepers. In the West Indies, sleep paralysis was called ”kokma” and meant a ghost baby who jumped on the sleeper’s chest and attacked the throat.
In Intruder dreams, the dreamer hallucinates an extremely vivid stranger in their midst. The dreamer may even imagine that they are hearing the intruder speak or hear their footsteps. These dreams are often accompanied by fear and hyper-alertness. Scientists think that the areas of our brain responsible for heightened vigilance are being acted on during these dreams.
Unusual Bodily Experience
This is the category of alien abduction dreams! It’s a bit of a catch-all category. In Unusual Bodily Experience dreams, the dreamer perceives that they are floating or flying or that they are out of their bodies completely. Sometimes a feeling of bliss accompanies this dream as well. Researchers think that the neurons responsible for sensing body position, orientation, and movement may be misfiring during this type of dream.
What Causes Hypnagogic Dreams?
The short answer is: Science isn’t sure. After 2,500 years of research, accelerated in recent decades by technology like brain monitoring equipment and a better understanding of neural networks, there is no way to say for sure why people hallucinate when falling asleep.
Because we don’t know why they happen, no one can say for sure if they are dangerous or how to stop them. There is evidence both from scientific studies and historical reports that such dreams are more likely to happen when you are sleeping on your back.
If you have frightening hypnagogic dreams on a regular basis, talk to your doctor. Your sleep quality is being affected, and a sleep specialist may be called in to make sure you start to rest better.
But hypnagogic dreams themselves seem to be a normal part of life’s rich pageant, across cultures and the centuries. Paul McCartney and Keith Richards both evidently have them, and who’s lived richer lives than those guys? If selling out stadium rock concerts well into your eighth decade comes from hypnagogia, sign us up.
Purple can’t guarantee you’ll dream up a legendary rock song, but you will sleep better on a Purple mattress. Find out why.