That sudden fall that wakes you up in the middle of the night: what is really happening in your brain?

you might think

These nocturnal jerks, which specialists call “hypnic jerks,” are sudden and involuntary muscle contractions that occur at the precise moment one falls asleep. They are often accompanied by a sensation of vertigo falling or a brief, disturbing dream.

What does this feeling feel like?

A sudden spasm that jolts you awake. A sensation of continue reading …