The Purpose of Sleep? To Forget. 人為什麼需要睡眠？為了遺忘

Hank Morgan/Science Source
A PET scan of a brain during normal sleep. Two scientists say sleep may help the brain prune back unneeded synapses.
The Purpose of Sleep? To Forget, Scientists Say - 纽约时报 国际生活
http://cn.nytstyle.com/science/20170207/sleep-memory-brain-forgetting/en-us/