Sleep is divided into REM and four stages of non-REM; each has a distinct brain wave frequency.

睡眠过程可分为快速眼动阶段和四个非快速眼动阶段，每个阶段的脑波频率都不一样。

youdao

Sleep is divided into REM and four stages of non-REM; each has a distinct brain wave frequency.

睡眠过程可分为快速眼动阶段和四个非快速眼动阶段，每个阶段的脑波频率都不一样。

youdao