We've talked about how my
guinea pig inherently loves carrots and responds to
them by being excited. We said that the carrots are
the unconditioned stimulus because they naturally
elicit the behavior of her being excited. So excitement in this case
is the unconditioned response to carrots. Now in order for me
to give her a carrot, I have to open my
refrigerator door. But since my refrigerator
door is broken, it makes a loud popping noise
whenever it's been opened. So the noise of the
refrigerator door was the neutral stimulus
because on its own, it didn't initially make
my guinea pig excited. But since my guinea pig heard
that popping sound every time I went to get her a
carrot, the popping sound was paired with the
presentation of a carrot, and eventually when she
heard that popping sound, she acted excited, as if she
was about to receive a carrot. And even if I just to
open the refrigerator door to make myself a snack, she
would respond that same way. Since now she responds to
the sound of the refrigerator door in the same way she
responds to a carrot, the sound of the
refrigerator door is no longer a neutral stimulus. It's a conditioned stimulus. And when something responds
to a conditioned stimulus, that response is referred to
as a conditioned response. But I started to notice
an interesting phenomenon. Sometimes I would see
her acting excited when I would open my desk
drawer, which also happens to make a loud popping
sound because it gets stuck a lot from having so many
papers and things inside of it. While the two popping sounds
have their differences, to my guinea pig they
sounded similar enough that the sound of my
desk drawer opening was able to cause excitement
in her almost as much as the sound of the
refrigerator door opening. And the term for this
is generalization. A generalization is a
tendency for stimulus, similar to the
conditioned stimulus, to elicit a response similar
to the conditioned response. And the idea to
take away from this is usually the more
similar the new stimulus is to the original
conditioned stimulus, the greater the conditioned
response will be. So the sound of my
desk drawer opening and the sound of my
refrigerator door opening sound similar enough to elicit
the response to my guinea pig behaving excitedly, the same
way she behaves about carrots. So we call that generalization. And generalization has
an adaptive value to it because it allows
us, whether we're talking about humans
or other animals, to make an appropriate
response to similar stimuli. For instance, you
may know exactly what your best friend's
smile looks like. And their smile probably
elicits feelings of joy in you. However, when it comes
to meeting someone new for the first time, if
you see them smile at you, it will probably also
elicit feelings of joy. So that's the idea
behind generalization. Now, I don't want you to think
everything is broken or stuck in my apartment. My dresser drawer
actually opens just fine. It makes a sound. But it's more a rumbling
sound than a popping sound. And when I open
my dresser drawer, my guinea pig does not
respond to the sound by behaving excitedly. And the term for this
is discrimination. And discrimination is when
a human or any other type of animal learns to make
a particular response to some stimuli,
but not to others. Discrimination also
has adaptive value because it's important
to respond differently to related stimuli. You wouldn't want to respond
to all loud sounds in exactly the same way. I mean think about it. Wouldn't you respond
differently to the loud bang of a drum versus a
loud bang of a gunshot? I know I would. Now, we've talked about
how my guinea pig behaves excited about the sound of the
refrigerator door opening, even when I'm opening it to
make a snack for myself, with no intention to
give her a carrot. And I know this because
it's happened a few times. And if she doesn't receive
a carrot for a few instances every so often,
that's no big deal. The classical
conditioning can endure. And she continues to
respond to sound of the door by behaving excitedly. However, if I decided to stop
giving her carrots altogether, eventually she would learn that
the sound the refrigerator door alone isn't followed
by a carrot. And the sound of the
refrigerator door would gradually stop making
her behave the same way she behaves when she
receives a carrot. And we refer to this
phenomenon as extinction. And it's when the conditioned
stimulus is repeatedly presented without the
unconditioned stimulus. And so, eventually, the
conditioned stimulus is no longer able to elicit
the conditioned response. But don't think of extinction
as something that bad unless you're an
endangered species. The process of extinction
is used in therapy to treat phobias. For instance if you
were afraid of heights, a therapist might use
the concept of extinction by exposing you
to various heights and eventually the
stimulus of heights would no longer elicit
the same response of fear. Finally, let's say my guinea
pig now no longer responds to the sound of my
refrigerator door opening. But suddenly, out
of the blue one day, she hears the
refrigerator door opening and spontaneously responds
with some level of excitement. The spontaneous occurrence
of the previously conditioned response is what's known
as spontaneous recovery. And no one really
knows why this happens. Generally when
spontaneous recovery of a conditioned
response occurs, it doesn't persist
for very long. And it usually isn't quite
as strong as it used to be. So maybe instead of
behaving extremely excited to the sound of
the refrigerator door, she just seems kind
of intrigued, at least more than usual. So that's spontaneous recovery. So now you know the
four common phenomena associated with classical
conditioning-- generalization, discrimination, extinction,
and spontaneous recovery.