Components of Classical Conditioning
Classical conditioning or Pavlovian conditioning (named after Russian physiologist Ivan Pavlov) is the association of an automatic reaction with a neutral occurrence.
It is a pure and simple form of associative learning. Classical conditioning works on things we don't consciously control, things controlled by the autonomic nervous system.
An unconditioned stimulus (something that elicits an automatic response) will cause an unconditioned response (an automatic response). If an unconditioned stimulus is followed closely by a neutral stimulus (something that doesn't elicit any particular response) an association is formed. With repeated pairings the neutral stimulus will become a conditioned stimulus (something that takes on the significance of the unconditioned stimulus) and will elicit a conditioned response (whatever the unconditioned response was).
For example, if a balloon is inflated in front of you until it bursts, you will be startled and react defensively. This will cause you to react defensively the next time you see a balloon that you believe is being over inflated, although nothing startling has happened yet.
The automatic reaction is called an unconditioned response (UR) because we don't have to learn or be told to recoil from a startling sound. The unconditioned stimulus (US) is the loud noise coupled with the visual change of the bursting balloon. The neutral occurrence is called a conditioned stimulus (CS) because seeing a large balloon is no reason to react defensively. We do, only because we have learned to associate a large balloon with the startled sensation that the bursting causes. The conditioned response (CR) is to flinch. This is elicited by a seemingly neutral occurrence (an over inflated balloon).
Classical conditioning is useful in two main ways. First, it allows us to recognize a stimulus that isn't harmful in itself (a dog growling) and respond appropriately. (Avoid it.) Second, for behaviour modification. We can make a point of associating positive feelings with a particular stimulus. The second result can also be accomplished with operant conditioning.
The following are important parts of classical conditioning.
Stages of Classical Conditioning
Acquisition- This is the learning phase when the CS is paired with the US repeatedly.
If the UR is strong enough it might only take one pairing. If we get sick (UR) after eating a new food (CS) we will learn to associate sickness with that food and avoid it even if the food wasn't the cause of our sickness.
If the UR is weaker, it will take several pairings to condition the response. If a researcher shoots a stream of air into your eyes immediately after a tone sounds, eventually you'll blink at the sound of the tone.
During the acquisition phase, the timing of the delay between the CS and US is important. The CS must be followed quickly by the US, and they should end at the same time. The optimum delay seems to be about half a second. Exceptions are possible if the UR is strong, as in the example of getting sick after eating something new.
Extinction- When the US no longer follows the CS the response will gradually diminish until it extinguishes. Someone could have a conditioned fear of dogs from being bitten (US) when they were young. If they have contact with friendly dogs without the US (getting bitten) their fear (CR) will gradually reduce and then disappear.
Extinction is very important. If we watch a scary scene in a movie, set in a garage, we might develop a CR of fear when we enter a garage. As a temporary response this is a minor inconvenience, but if it was permanent it could become a serious impediment in our daily life. After entering a garage a few times and finding that nothing scary happens, the fear response (CR) will disappear.
Spontaneous Recovery- At times an extinguished response (CR) will come back unexpectedly. Someone who is now at ease with dogs could find themselves feeling fearful if they come in contact with a dog after some time has passed.
This implies that the CR is still present in a weakened state. It also means that a CR can be reacquired quickly, because some of the original learning is retained.
Generalization- This is when the CS expands to similar things. If a child is bitten by a dog, the fear they feel (CR) on seeing a dog, (CS) can expand to include a fear of any four-legged animal of a similar size. They could be afraid of lambs at a petting zoo.
Generalization is unpleasant when it spreads fear or anxiety to benign objects or situations.
However, generalization is useful for learning. If we touch one hot stove we generalize our aversion to being burned to all sizes and colors of stove and any other object that reminds us of a stove that could also be hot.(Grills, barbecues)
Discrimination- This is when we can distinguish different stimuli. After being bitten by a dog (US), we can learn to distinguish between dogs that are growling or barking from ones that are wagging their tails, and learn to avoid the aggressive ones only.
Likewise, after being burned on a hot stove (US) we can learn to discriminate between hot and cold stoves.
Key terms of classical conditioning
Unconditoned Stimulus (US)
Stimulus that elicits an automatic response
A fun party, A loud noise
Unconditoned Response (UR)
Response that is naturally elicited by the US
Conditioned Stimulus (CS)
Stimulus that elicits a response because of its pairing with the US
Song played at the party, An over inflated balloon
Conditioned Response (CR)
Response that is elicited by the CS