How do we explain

我们如何解释
when babies come to know things that they didn't originally know?

婴儿何时掌握了原本并不知道的知识
Well, one answer is neural maturation,

答案之一就是神经元的成熟
growth of the brain.

也就是大脑的发育
Most of the neurons you have now in your head,

此时此刻你头脑中的大部分神经元
right now, you had when you were in your mother's uterus.

早在你处于母亲子宫中时就已经拥有
What happens in development

发展中所发生的主要事情
isn't for the most part the growth of new neurons.

并非是新神经元的生长
It's for the most part pruning, getting rid of neurons.

而更多的是在去除清除神经元
So, the neural structures change radically

由于婴儿在发展过程中
as babies kind of get rid of excess neurons

会清除掉许多多余神经元
through development.

因此神经结构会发生急速的变化