why we jerk when falling asleep, con't

The answer to that is given really well in “A Layman’s Guide to Psychiatry and Psychoanalysis” by Eric Bern, MD. The jerk is caused by the release or interaction of a hormone and is a standard ingredient of “normal” sleep. Very interesting reading in that book, but I haven’t seen a copy since the 70’s when I left my seabag of fantastic now-rare books and reel-to-reel tapes of synthesizer compositions on the stairs in a bus station in Oklahoma…

That jerking motion is always preceded by some dream of falling or dodging a vehicle or even a wild animal attack. In many years of pain management via opioid meds, that response was greatly amplified by the meds, making me jump virtually off the surface of the bed. An unpleasant side effect, for sure, but I’ve always wondered if the chemical that causes it is related to our natural opioid receptors.

Really great site here! Always nice to “unlearn” some of the ridiculous myths out in the world :dubious:

salsalover from the chesapeake bay

Welcome to the message board salsalover, hope you enjoy the stay!

Here’s a link to the article in question (why must we jerk). Just helps make sure people don’t assume you’re referring to shooting T-Rexes or something. I also didn’t realise that is what people would assume.

Anyway, it’s good to know about the hormone. I think there’s another chemical produced that inhibits movement during normal sleep, I’d love to know what it’s called if anyone has the answers?

The most graphic example I’ve seen of this was over at a friend’s house, a gentleman that really likes his red wines, especially Cabernets. On a tour through it we were shown the carpeted bar room and from a corner near a chair to five feet away was a long purple stain. His wife informed me that that was where he’d fallen asleep and then, jerking, had thrown the contents of his wine glass out in a most displeasing arc.

I ventured that it’s amazing what carpet cleaning services can accomplish to clean up stains like that. She agreed and pointed out the faint, almost but not completely gone stain mirroring the deeper one. That, she said, was the first time he’d jerked and distributed the contents. They’d had it professionally cleaned and not a week later he started to fall asleep, jerked and threw the wine in a near perfect copy of the first time.

So, graphically at least, it would appear these motions are not only repeatable but also remarkable in their consistency.