Transcript Psychology: Pavlov, Watson, Skinner

Learning Experiments and Concepts
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What is learning?
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Albert Bandura argued that individuals,
especially children learn aggressive responses
from observing others, either personally or
through the media and environment.
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There are four component processes
influenced by the observer’s behavior
following exposure to models.
These components include: attention;
retention; motor reproduction; and
motivation
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PAVLOV’S DOG
He noted that dogs were not only responding to a
biological need (hunger), but also a need
developed by learning.
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PAVLOV’S DOG
Even when Pavlov took away the meat powder, the
dog continued to salivate at the sound of the
tuning fork.
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PRINCIPLES OF CLASSICAL CONDITIONING
In classical conditioning, an organism learns
to associate one stimulus with another. The
organism learns that the first stimulus is a
cue for the second stimulus. In Pavlov’s
experiment above, the tuning fork cued the
dogs that food might be coming. Following is
an example of classical conditioning.
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PAVLOV’S DOG
In technical terms, the food is an
unconditioned stimulus (UCS) and the
salivation is the unconditioned response (UCR).
The bell is a neutral stimulus until the dog
learns to associate the bell with food. Then the
bell becomes a conditioned stimulus (CS) which
produces the conditioned response (CR) of
salivation after repeated pairings between the
bell and food.
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WATSON’S BABY ALBERT
John B. Watson was interested in how classical
conditioning could be applied to humans.
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KEY CONCEPTS OF CLASSICAL CONDITIONING
Unconditioned Stimulus (UCS)
A stimulus that elicits a response without conditioning
Unconditioned Response (UCR)
Automatic response elicited by the unconditioned stimulus
Conditioned Stimulus (CS)
A neutral stimulus that when paired with an unconditioned
stimulus (UCS) elicits a similar response
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Conditioned Response (CR)
A response that is learned by pairing the originally neutral
conditioned stimulus (CS) with the
unconditioned stimulus (UCS)
Perhaps
Psychology’s
most famous
Experiment
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Acquisition
The acquisition phase is the consistent parings of the CS (bell) and
the UCS (food) that produces a CR (salivation). In the example above,
this phase occurs when the dog begins to salivate at the sound of
the bell. Conditioning occurs more rapidly when the food follows the
bell by a half a second.
Extinction
The extinction phase is when the conditioned response no longer
occurs after repeated pairings without the unconditioned stimulus.
The dog’s response to the bell can be extinguished by repeatedly
presenting the bell (CS) without the food (UCS). The dog has not
completely forgotten the association between the bell and the food.
If the experimenter waits a day, the dog may have a spontaneous
recovery of the conditioned response and salivate again to the bell.
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Generalization
Occurs when there is a small difference in the presented
stimulus and the original conditioned stimulus. If Pavlov’s
dog heard a bell of a similar tone, the dog would still salivate.
Discrimination
The opposite of generalization, discrimination happens when
a conditioned response does not occur when there is a
difference between the presented stimulus and the original
conditioned stimulus. If Pavlov’s dog heard a bell with a
different tone and was not awarded the unconditioned
stimulus (food), the dog would learn not to salivate to the
second tone.
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SKINNER’S OPERANT CONDITIONING
Beginning in the 1930’s, Skinner started his experimentation
on the behavior of animals. Skinner's quest was to observe
the relationship between observable stimuli and response.
Essentially, he wanted to know why these animals behaved
the way that they do. Skinner controlled his experiments by
using “Skinner boxes.”
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PRINCIPLES OF OPERANT CONDITIONING
The main principles of operant conditioning,
as defined by Skinner, are reinforcement,
punishment, shaping, extinction,
discrimination, and generalization.
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KEY CONCEPTS OF OPERANT CONDITIONING
Reinforcement
The process in which a behavior is strengthened,
and thus, more likely to happen again.
Positive Reinforcement
Making a behavior stronger by following the
behavior with a pleasant stimulus. For example, a
rat presses a lever and receives food.
Negative Reinforcement
Making a behavior stronger by taking away a
negative stimulus. For example, a rat presses a
lever and turns off the electric shock
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Punishment
The process in which a behavior is weakened, and thus, less likely to
happen again.
Negative Punishment
Reducing a behavior by removing a pleasant stimulus when the
behavior occurs. If the rat was previously given food for each lever
press, but now receives food consistently when not pressing the
lever (and not when it presses the lever), the rat will learn to stop
pressing the lever.
Positive Punishment
Reducing a behavior by presenting an unpleasant stimulus when the
behavior occurs. If the rat previously pressed the lever and received
food and now receives a shock, the rat will learn not to press the
lever.
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Shaping
Technique of reinforcement used to teach new behaviors. At
the beginning, people/animals are reinforced for easy tasks,
and then increasingly need to perform more difficult tasks in
order to receive reinforcement. For example, originally the rat
is given a food pellet for one lever press, but we gradually
increase the number of times it needs to press to receive
food, the rat will increase the number of presses.
Extinction
The elimination of the behavior by stopping reinforcement of
the behavior. For example, a rat who received food when
pressing a bar, receives food no longer, will gradually
decrease the amount of lever presses until the rat eventually
stops lever pressing.
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Generalization
In generalization, a behavior may be performed in
more than one situation. For example, the rat who
receives food by pressing one lever, may press a
second lever in the cage in hopes that it will receive
food.
Discrimination
Learning that a behavior will be rewarded in one
situation, but not another. For example, the rat
does not receive food from the second lever and
realizes that by pressing the first lever only, he will
receive food.