[[Wikipedia: Neuroscience of sleep |Sleep]] is a complex phenomenon that causes physiological changes all over the body. However, it mainly affects the brain. According to the electrical activities in the brain, sleep is divided into [[Wikipedia:Rapid eye movement sleep |rapid-eye movement]] (REM) and non-REM (NREM) stages. NREM sleep is further divided into three stages according to the frequency and amplitude of brainwaves.
睡眠は体全体に生理学的変化をもたらす複雑な現象です。しかし、それは主に脳に影響を及ぼします。脳の電気活動により、睡眠はレム睡眠(REM)とノンレム睡眠(NREM)に分けられます。そしてさらに、NREM睡眠は脳波の周波数と振幅によって3つの段階に分けられています。