During the day, your brain is a beehive of activity—during NREM sleep, it is barely humming.
在白天,你的大脑就像一个活跃的蜂窝——在非快速眼动睡眠期间,它就几乎没有嗡嗡声了。
2
This occurs because during NREM sleep the automatic, metabolic system has exclusive control over breathing and the body uses less oxygen and produces less carbon dioxide.