right before or right during you give the dog some food

在喂食前或者喂食过程中
you--you ping a bell

你摇铃
the bell will cause the saliva to come forth.

铃声就会加速唾液的分泌
And, in fact, this is the apparatus that he used for his research.

这是他在研究时所使用的仪器
He developed the theory of classical conditioning

他通过区分两种条件作用
by making a distinction between two sorts of conditioning,

两种刺激反应关系
two sorts of stimulus response relationships.

提出了经典条件作用理论
One is unconditioned.

一个是无条件作用
An unconditioned is when an unconditioned stimulus

无条件作用是指
gives rise to an unconditioned response.

无条件刺激会引起无条件反应
And this is what you start off with.

这是我们的本能
So, if somebody pokes you with a stick and you say,

如果有人用棍子戳你