Source: bell: public domain; http://morguefile.com/archive/display/104336
In today's lesson, we're going to be talking about how learning occurs under behaviorism. If you remember, behavioral theory says that people are influenced by their external environments to behave, or to create actions, in certain kinds of ways. One of those ways is classical conditioning. Simply put, classical conditioning is when someone or something, like a dog, comes to associate a response to a stimulus, to a completely different stimulus that doesn't usually produce that response. Sounds a little bit wordy and complicated, but it'll become more clear with an example. And a famous one is that.
Ivan Pavlov was a Russian physiologist and natural scientists, who in the 1870s, did what he became famous for, in his dog experiments.
It's important to realize first, what a stimulus and a response is. A stimulus is something that happens in the external environment. Something outside of the person. A response is something that a subject does because of a stimulus. Some kind of behavior.
So this is how Pavlov's experiments worked. He took his dogs, and first he gave them dog food. And then he measured how much they salivate. So what he called the unconditioned stimulus, or US, was the food. The thing outside of the dogs. And the unconditioned response was the salivation. In other words, a dog always salivates in response to food. And people do it, too. If you think about food right now, you can't help but salivate.
Next, what Pavlov did was, he took a neutral stimulus. Something that normally doesn't create a response. In this case, it was a bell. And he put it right before the unconditioned stimulus of the food. Then he rang the bell, he presented the dog with the food, and then the dog would still salivate, because that's the unconditioned response. He would continue to pair this neutral stimulus with an unconditioned stimulus, over, and over, and over, again. And what he found is that, over time, the dog learned to associate the bell with the food. So the dog would start to salivate as a response of hearing the bell, and not even seeing the food.
This is what he referred to as a conditioned stimulus. It was changing the bell into a stimulus that created the response-- the new conditioned response-- of salivating. And this is what he called classical conditioning. Going from an unconditioned stimulus, an unconditioned response. All the way down to a conditioned stimulus, and a conditioned response.
This type of learning can be used to explain more and more complex behaviors. For example, how we learn to value money through early associations with things that we want. We see that money gets what we want, and so eventually we start to value of money in itself.
Over time, these conditioned stimuli and response connections become weaker and weaker without the unconditioned stimulus being there. So the dog would eventually stop associating the bell with the food, and it would stop salivating when it heard the bell all by itself. This is what we call extinction. , Or in other words, forgetting the responses and forgetting what was learned. However, spontaneous recovery could sometimes occur after extinction. This means when a learned response returned, even though it was thought to be extinct. This explains why, after some traumatic event, say in someone's childhood, they can have a recurrence of feelings later on their life, when they're an adult. Spontaneous recovery.
What has also been examined under classical conditioning is the difference between stimulus generalization and stimulus discrimination. Generalization is when a person responds to a stimulus that's similar to one that they've learned, with the same learned response. For example, if you're afraid of a barking dog-- something that scared you when you were a child-- you might respond with fear, in the same way, to a stuffed dog or a picture of a dog. Even though it's not the same, it's similar enough. This is especially common early in life when we don't have as many experiences, and so we don't understand what the differences are.
Stimulus discrimination is when a person learns to differentiate between similar stimuli, and not to respond to them in the same way. For example, this is like becoming not afraid of the picture, or the stuffed barking dog. Learning to understand that those things are different from each other. This is something that occurs over time, in response to our new experiences.
Classical conditioning can be used in different types of therapies, and is found to actually have results. One example is in desensitization therapy, when a person that's created an unwanted emotional response to some kind of stimuli-- what we call a conditioned emotional response, or CER-- is helped by the therapist to unlearn this response. For example, if you have a snake phobia, let's say. You're afraid, and that's your conditioned emotional response to snakes. Then what they're trying to do is get extinction to occur through gradual exposure to the thing that you're afraid. So you might start by seeing pictures of snakes. Or you might see somebody holding a snake, and eventually you want to get to the point where you become exposed to the snake, and you can actually touch it yourself. And so you're learning to not be afraid of that snake.