When we think about learning, we often picture students in a classroom or lecture hall, books open on their desks,
当我们想到学习时，我们通常会想像学生在教室或报告厅的画面，摊开在桌子上的课本，
listening intently to a teacher or professor in the front of the room.
认真地听着前面的老师或教授授课。
But in psychology, learning means something else.
但是在心理学里面，学习则是另一回事。
To psychologists, learning is a long-term change in behavior that's based on experience.
对心理学家而言，学习是基于体验的长期的行为改变。
Two of the main types of learning are called classical conditioning and operant, or instrumental, conditioning.
学习的两大主要类型为经典条件性反射和操作性条件反射。
Let's talk about classical conditioning first.
我们先来说说经典条件反射。
In the 1890's, a Russian physiologist named Ivan Pavlov did some really famous experiments on dogs.
在1890年代，一个名为伊万·巴甫洛夫的俄罗斯生理学家，在狗身上做了非常著名的实验。
He showed dogs some food and rang a bell at the same time.
他在给狗食物的同时也摇响了铃当。
After a while, the dogs would associate the bell with the food.
不久以后，这些狗就将食物和铃当联系起来。
They would learn that when they heard the bell, they would get fed.
它们明白了当有铃声响起的时候，它们就会有吃的。
Eventually, just ringing the bell made the dogs salivate.
最后，只要铃声一响，这些狗就开始分泌唾液。
They learned to expect food at the sound of a bell.
它们觉得有铃声就应该有食物。
You see, under normal conditions, the sight and smell of food causes a dog to salivate.
你们知道，在通常情况下，只有看到闻到食物狗才会分泌唾液。
We call the food an unconditioned stimulus, and we call salivation the unconditioned response.
我们称食物为无条件刺激，我们称分泌唾液为无条件反射。
Nobody trains a dog to salivate over some steak.
没有人需要教一只狗如何在看到牛排时分泌唾液。
However, when we pair an unconditioned stimulus like food with something that was previously neutral, like the sound of a bell,
然而，当我们将比如食物这样的一个无条件刺激，与比如铃声这样的原来是中性的东西联结起来的时候，
that neutral stimulus becomes a conditioned stimulus.
那个中性的刺激物变成了条件刺激。
And so classical conditioning was discovered.
于是经典条件反射理论诞生了。
We see how this works with animals, but how does it work with humans?
我们可以看到它在动物身上的应用，但应用到人身上是怎样的？
In exactly the same way. Let's say that one day you go to the doctor to get a shot.
也是完全一样的。比如某一天你去医生那里打针。
She says, "Don't worry, this won't hurt a bit," and then gives you the most painful shot you've ever had.
她说：“不要怕，这一点都不会疼”，然后她给你打了你这辈子打过的最疼的一针。

A few weeks later you go to the dentist for a check-up.
几个星期以后，你去一个牙医那里检查。
He starts to put a mirror in your mouth to examine your teeth, and he says, "Don't worry, this won't hurt a bit."
他开始把一个镜子放在你的嘴巴里来检查你的牙齿，他说：“不要怕，这一点都不会疼”。
Even though you know the mirror won't hurt, you jump out of the chair and run, screaming from the room.
虽然你知道这个镜子不会让你疼，你却立马从椅子上跳起来撒腿就跑，边跑边叫。
When you went to get a shot, the words, "This won't hurt a bit," became a conditioned stimulus
当你去打针的时候，“这一点都不会疼”的字眼成为了一个条件刺激，
when they were paired with pain of the shot, the unconditioned stimulus,
跟打针的疼痛联结在一起，打针的疼痛则是无条件刺激，
which was followed by your conditioned response of getting the heck out of there.
于是就有了你的条件反射，也就是跑得远远的。
Classical conditioning in action.
经典条件反射起了作用。
Operant conditioning explains how consequences lead to changes in voluntary behavior.
操作性条件反射解释的是结果如何导致自愿的行为改变。
So how does operant conditioning work?
那操作性条件反射是怎么一回事呢？
There are two main components in operant conditioning: reinforcement and punishment.
操作性条件反射主要有两个组成部分：强化和惩罚。
Reinforcers make it more likely that you'll do something again, while punishers make it less likely.
强化物让你更可能重复某一行为，而惩罚则相反。
Reinforcement and punishment can be positive or negative, but this doesn't mean good and bad.
强化和惩罚可以是积极的也可以是消极的，但这不是指好与坏。
Positive means the addition of a stimulus, like getting dessert after you finish your veggies,
积极指的是增加某一刺激，比如在你吃完蔬菜后给你甜品，
and negative means the removal of a stimulus, like getting a night of no homework because you did well on an exam.
消极指的是去除某一刺激，比如因为你考试成绩好而给你取消作业。
Let's look at an example of operant conditioning.
让我们来看一个操作性条件反射的例子。
After eating dinner with your family, you clear the table and wash the dishes.
在跟你的家人用完晚餐后，你收拾了桌子，洗了碗筷。
When you're done, your mom gives you a big hug and says, "Thank you for helping me."
你做好这些以后，你的妈妈给了你一个大大的拥抱，说：“谢谢你帮我。”
In this situation, your mom's response is positive reinforcement if it makes you more likely to repeat the operant response,
在这个情景里面，你妈妈的回应是积极的强化--如果你以后更可能重复那个操作性反应，
which is to clear the table and wash the dishes.
也就是收拾桌子和洗碗筷。
Operant conditioning is everywhere in our daily lives.
操作性条件反射在我们的日常生活中随处可见。
There aren't many things we do that haven't been influenced at some point by operant conditioning.
我们做的事情里面很少有不被操作性条件反射影响过的。
We even see operant conditioning in some extraordinary situations.
我们甚至见过一些不寻常的操作性条件反射的例子。
One group of scientists showed the power of operant conditioning by teaching pigeons to be art connoisseurs.
一群科学家们向我们展示了操作性条件反射的力量--他们训练鸽子为艺术鉴赏家。
Using food as a positive reinforcer, scientists have taught pigeons to select paintings by Monet over those by Picasso.
通过把食物作为积极强化物，科学家们教会了鸽子选择莫奈的画，而非毕加索的画。
When showed works of other artists,
当这些鸽子看到其他艺术家的画时，
scientists observed stimulus generalization as the pigeons chose the Impressionists over the Cubists.
科学家们观察到了刺激泛化，这些鸽子选择了印象派的画，而非立体派的画。
Maybe next they'll condition the pigeons to paint their own masterpieces.
也许接下来他们就可以训练鸽子画出它们自己的杰作。