Sleep Paralysis

About 30% of normal people find that occasionally, while awakening, they cannot move. This phenomenon is called sleep paralysis. Probably a neural center in a midbrain structure called the medulla (the same area which triggers cataplexy, above) is involved in sleep paralysis. The muscle inhibition of REM sleep "hangs on" a little too long. The person wakes up but remains paralyzed, unable to move.

What is sleep paralysis?

A student reports a typical episode:

One morning as I was awakening I found myself in this strange state. It was a feeling hard to describe yet it is still clear in my mind. I could hear my mother in the kitchen; she was talking to my sister as she fried some bacon. Strangely enough I could smell the bacon and could even hear them talking, yet my body was paralyzed. I wanted to move desperately. I tried yelling out to them to come and help me but my mouth just wouldn't move. I even tried rolling out of bed but could not move a muscle. My mind began to wander as I lay there helplessly. I soon recalled hearing my mother say something about a state of sleep when breathing becomes difficult and you can't move. She always called it a witch riding your back. I soon snapped out of it and awoke in a rush. I was so glad to have my body under control again. [Author's files]

What response to sleep paralysis was suggested to a student?

Another student reported that paralysis-upon-awakening ran in her family on the female side: her mother and grandmother both experienced it frequently. They said the best thing to do was stay calm, go back to sleep, and wake up again. The student practiced this advice but said it was still an unpleasant experience.

How might sleep paralysis be linked to claims of alien abductions?

Sleep paralysis could be categorized as a hypnopompic state because it is a transition between sleep and wakefulness. Like other hypnopompic states, it can be accompanied by vivid hallucinations. Many scholars believe that reports of alien abductions are stimulated by episodes of sleep paralysis, because both are marked by the inability to move and by story-like hallucinations similar to REM dreams (Kristoff, 1999).


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