Download Part II Classical Conditioning

Summer Assignment A2 Psychology
2015-2016
Please check my website http://schoolsites.leeschools.net/nfm/DoloresAHol/default.aspx
For lecture notes and a pacing guide for you on my website for the course
You will be tested September 1, 2015 on the summer material. Please create your own notes for each, I am
providing you a hand-out on Operant Conditioning-please mark-up and anecdotal note.
Part I
Behaviorist Perspective-
Part II Classical Conditioning-
The specialist terminology of classical conditioning can seem confusing at first, but it is important if you are
to be able to describe the process accurately. Make sure you can use the following terms correctly:
Unconditioned stimulus
Unconditioned response
Neutral stimulus
Conditioned stimulus
Conditioned response
Pavlov
Watson
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Operant Conditioning
This factsheet:
• Summarizes the main features of operant
conditioning; and
• Assesses the role of operant conditioning in the
behavior of non-human animals.
Consequences of behavior
When an animal performs a behavior, there can be
many types of consequence. The consequence may be
something pleasant which will make the animal repeat
the behavior or something nasty which will stop the
animal from doing that behavior again.
We have underlined keywords that you should know
for the exam.
What is operant conditioning?
• Operant conditioning explains how animals learn
certain behaviors.
• Operant conditioning focuses on the behavior an
animal makes and the consequence of that behavior.
The consequence of the behavior determines how
likely it is that the animal will do that behavior again.
• The consequence of a behavior can be positive
(something pleasant) or negative (something
unpleasant). Whether the consequence is positive or
negative determines whether the behavior will be
repeated in future (i.e., learnt).
• There are two laws:
o The law of reinforcement → a positive
reward/reinforcement
(e.g.,
food/praise)
increases the chance of learning a behavior.
o The law of contiguity → the behavior and
consequence (e.g., reward) must happen close
enough together in time for learning to occur.
Schedules of reinforcement
It is possible to give reinforcement in two ways –
continuous and partial.
• Continuous reinforcement gives a reward after
every response the animal makes. For example, the
rat will get a pellet of food after every lever press.
• Partial reinforcement gives a reward after only
some responses. Skinner found four schedules of
partial reinforcement:
1. Fixed ratio schedule – reward after a certain
number of responses. For example, a food pellet
after every 8 presses on the lever.
2. Variable ratio schedule – reward after a certain
number of responses on average. For example,
food after 8 presses on average, so there is
sometimes a reward after the 6th press and
sometimes after the 10th press.
3. Fixed interval schedule – reward following the
first response after a certain interval of time. For
example, food for a lever press every 5 minutes.
4. Variable interval schedule – as for fixed interval,
but on average. For example, food reward about
every two minutes (sometimes 1.5 minutes,
sometimes 2.5 minutes).
An example of operant conditioning Imagine that your new puppy is in the
garden and wants to come in, but the door
is shut. On one occasion your puppy sits
by the door and accidentally taps the door with his
paw. You hear this and quickly respond by opening
the door. Your puppy finds this pleasant as he wants to
be with you. Your puppy will gradually learn that
tapping the door means that you let him into the
house.
Partial reinforcement is better in conditioning a
behavior than continuous reinforcement. It is better
because the occasional lack of a reward is normal. In
continuous reinforcement, the animal expects a reward
every time, so the lack reduces the chance of the
behavior being repeated.
Extinction is when a behavior is extinguished
(unlearned) if the response is not reinforced. The
behavior stops as the animal learns that the behavior
has no consequence. Partial reinforcement leads to
slower extinction than continuous reinforcement. The
extinction
is slower because the animal is used to getting rewards
infrequently and keeps going for a while in expectation
of a reward.
The effect of his behavior (tapping the door) results in
something positive (you opening the door). So, your
puppy has learnt the behavior by the effect
(consequence) it had on the environment.
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Type of consequence
Description
Example
Positive reinforcement
Increases the chance of a behavior occurring
again by providing a pleasant consequence.
Negative reinforcement Increases the chance of a behavior occurring
again by removing (or escape from) an
unpleasant consequence.
Secondary
Primary reinforcers (rewards) are linked with
reinforcement
secondary reinforcers.
Punishment
Receiving a reward (e.g., food) after
pressing a lever.
Moving away from an electric shock.
Food is a primary reinforcer whereas
a mother is a secondary reinforcer
because she provides the food.
Giving an electric shock.
Decreases the chance
Positive punishment
of a behavior occurring provides a negative
again by providing an
consequence by
unpleasant
giving something.
consequence. There are Negative punishment
Removing food
two types of
provides a negative
punishment positive
consequence by
punishment and
removing something.
negative punishment.
Exam Hint: Learn the Keywords underlined. Candidates should be able to describe, give types of consequence
and schedules of reinforcement for operant conditioning,
Another name for operant conditioning is ‘instrumental conditioning’. The theory of operant conditioning
developed from classical conditioning (see Glossary). Thorndike developed this theory and then Skinner took
it further (see text boxes below).
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Evaluating the role of operant conditioning in the behavior of non-human animals
In this section, we will look at the strengths and limitations of operant conditioning and how it relates to behavior of
non-human animals.
Strengths
• Operant conditioning explains a wide range of phenomena, such as learning language and phobias.
•
It has practical applications, such as training animals (see Tortoises and Shaping text boxes below).
• It examines learning in controlled experiments in the laboratory. The findings are easily replicated.
• Operant conditioning enables animals to behave efficiently in their environment. For example, operant conditioning
enables the best foraging strategies in birds. They learn where they are most likely to find food and return to these
areas to constantly check for food (rewards).
Tortoises
Weiss and Wilson (2003) used positive reinforcement to train four tortoises to approach a target (a
red plastic ball on a stick) and hold their
head still while touching the target. They were given food as a reward for doing this. Training the tortoises to do
this meant that it would be easier to take blood samples than if someone had to pick the tortoise up.
Shaping
Operant conditioning can train animals to do complex tasks by rewarding animals for a behavior that is similar to the
desired end behavior. The training happens step by step until the animal is doing the complex behavior. For example,
to get a tortoise to hold still at target, Weiss and Wilson began by rewarding the tortoise if it moved slightly towards
the target. They then rewarded it for standing next to the target and so on until it would hold its head still on the
target.
Cognitive Factors
Animals may use reasoning (cognitive factors) in learning a behavior. Operant conditioning ignores cognitive factors in
learning. However, some research has found that animals do use reasoning. For instance, in Mackintosh’s (1994)
study, rats pressed the lever in a Skinner box for a food reward. The experimenter then gave the rats an injection to
create an aversion to the food. They found that the rats eventually stopped pressing the lever. This finding is difficult
to explain without cognitive factors as the experimenters did nothing to directly stop the rats pressing the lever.
Instead the rats had associated the lever with the aversion.
Limitations
• Experiments on operant conditioning use animals and so there are ethical issues.
• As these experiments use just a few species of animal (e.g., cats, pigeons, rats), the findings may not generalize to
other species.
• Experimenters study operant conditioning in laboratories and so the findings may not be ecologically valid.
• Animals are learning unnatural behaviors that they would not do in the wild (e.g., pressing a lever).
• Operant conditioning does not take cognitive factors into account (see Cognitive Factors text box).
• Operant conditioning does account for innate abilities that adapt a species to its environment (See Pigs text box).
• Operant conditioning does not consider other forms of learning such as observational learning. For example, Sherry
and Galef (1984) found that birds learnt to open a tub of cream by watching other birds do it.
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