The Stuff of Dreams 梦的本质

课前问题

What is going on when a person experiences rapid eye-movements during sleep?

一个人在睡眠中经历快速眼动时发生了什么？

课文首句

It is fairly clear that the sleeping period must have some function, and because there is so much of it the function would seem to be important.

很清楚，睡眠期一定有某种功能，而且由于睡眠期很长，这种功能似乎很重要。