This frustrating sleep starts have another cool medical name, hypnagogic myoclonus.

催眠性肌阵挛。

There are positive sides to this hypnagogic period too.

催眠期也有积极的一面。

It's in this first stage of sleep you might experience hypnagogic sensations -- those brief moments when you feel like you're falling, and your body jerks, startling you.

睡眠的第一阶段，你可能会经历入睡前幻觉，例如你感觉你坠落，身体抽搐。