From ancient demons to alien abductions, paranormal tales reveal that “sleep paralysis” may be as old as sleep itself, reports The Atlantic.

Suddenly I’m awake. Something is on me. A shadow or a shape. Something nasty. I’m pinned to my bed and I can’t move a muscle. There are whispers, wicked whispers. I think I’m screaming but I make no sound. There’s a loud buzz, a whoosh, and I’m sucked out of myself, twisting, turning, then dragged. But through my ever-so-slightly-open eyes, I see my body is still motionless.

What I’m experiencing is literally a waking nightmare. It’s a state during which I’m awake but unable to move or cry for help, no matter what demons my mind conjures. The state has a name: Sleep Paralysis (SP), or more accurately in this case, Awareness During Sleep Paralysis (ASP). I’ve endured it hundreds of times before. And, as disturbing as it sounds, I’m far from the only one: People all over the world experience this terror. In fact, it’s as old as sleep itself.