Summary

The sleep helps reset our body and brain. Normally, sleep is comprised of two stages: Non-rapid eye movement stage and rapid eye movement stage (Shortened to NREM and REM). 

Within the NREM, there are sub-stages as follows:

1 Awake/Light sleep

2 Light sleep

3/4 Deep sleep

In stage 1, your heartbeat rate, body temperature and electrical brain activities slow down. 

In stage 3 and 4, your brain waves become active and powerful. Your immune system is recharged, cardiovascular system overhauled, and memory solidified.

Within REM

You start having wildest dreams. Your brain wave activities pick up. The brain works on the emotional first aid soothing the difficult emotional experiences you've had during the day. Your creativity and imagination is lit up. That's why sometimes you wake up with better ideas and solutions to once hard challenges.

The NREM and REM form a sleep cycle of 90 minutes. The brain starts the cycle every 90 minutes. The two fight for the domination of the brain.  In the first half of the night, NREM takes up more time. In the second half, REM takes up more time.

Lack of sleep will sever the communication between the prefrontal cortex and the amygdala. Amaygdala (emotion) will get out of control.

人的睡眠大体分为非眼动和眼动睡眠两个阶段。

其中，非眼动又分为4个小阶段，前2个是浅睡眠，后2个是深睡眠。

浅睡眠阶段，人的心跳、体温、脑电波活动都下降。

深睡眠阶段，脑电波开始活跃，人的免疫系统、心肺功能和记忆力开始恢复。

眼动阶段

人会做梦，创造力和想象力得到释放和加强，白天经历的情感刺激会得到舒缓和抚慰。所以有时候，人醒来会感觉很舒服，之前想不通的问题，也能接受或者找到解决办法了。

总结：所以说睡眠很重要，充足的睡眠更重要。眼动睡眠阶段就是心伤的疗愈过程呀！缺乏睡眠，人的情绪反应倾向于过激，容易失控。

Vocabulary

jump start 快速启动

neutral architecture 神经网络

听力原文链接 Source Link

https://www.ted.com/talks/matt_walker_a_walk_through_the_stages_of_sleep