Download operant conditioning

Chapter 5
5th Edition
Learning
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5-1
What is Learning?
• Learning is a relatively permanent change
in behavior or the potential to make a
response that occurs as a result of
experience.
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5-2
Classical Conditioning
• Classical conditioning is a form of
learning that occurs when two
stimuli—a neutral stimulus and an
unconditioned stimulus—that are
paired (presented together) become
associated with each other.
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Classical Conditioning
• A neutral stimulus (NS) is a stimulus
that, before conditioning, does not elicit a
particular response.
• An unconditioned stimulus (UCS) is a
stimulus that automatically produces a
response without any previous training.
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5-4
Classical Conditioning
• A conditioned stimulus (CS) is a neutral
stimulus that acquires the ability to elicit a
conditioned response after being paired
with an unconditioned stimulus.
• An unconditioned response (UCR) is a
reaction that is automatically produced
when an unconditioned stimulus is
presented.
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5-5
Classical Conditioning
• A conditioned response (CR) is a
response elicited by a conditioned
stimulus that has been paired with an
unconditioned stimulus; it is similar to the
unconditioned response.
• Several pairings of the NS and UCS
during an acquisition phase lead to a
situation in which the CS presented by
itself elicits a CR.
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Classical Conditioning
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5-7
Classical Conditioning
• Acquisition is the training stage during
which a particular response is learned
(occurs after a CS is presented).
• Several factors influence the acquisition of
CRs.
• Among them are the order in which the CS
and UCS are presented, the intensity of
the UCS, and the number of times the CS
and UCS are paired.
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5-8
Classical Conditioning
• The optimum sequence is for the CS to
precede the UCS (by about .50 second).
• The stronger the UCS, the stronger the
conditioning.
• The more times the CS and UCS are
presented together, the stronger the CR
becomes.
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5-9
Classical Conditioning
Acquisition patterns in classical conditioning when the UCS
is presented at different percentages on trials (a series of
presentations of stimuli).
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Classical Conditioning
• Extinction is a general term for a reduction and eventual
disappearance of a behavior; in the case of classical
conditioning, extinction occurs when repeated
presentation of the CS alone leads to a decrease in the
strength of the CR.
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Classical Conditioning
• Spontaneous recovery is the reappearance of
an extinguished CR after the passage of time.
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Classical Conditioning
• Generalization is the occurrence of
responses to stimuli that are similar to a
CS.
• Discrimination is the occurrence of
responses only to a specific CS.
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Classical Conditioning
• John Watson and Rosalie Rayner
demonstrated that emotions can be
learned by classically conditioning
9-month-old Little Albert to fear a white rat.
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5-14
Classical Conditioning
• Conditioning Little Albert to fear a white rat.
• The research conducted by Watson and Rayner
would not be considered ethical by present-day
standards.
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5-15
Classical Conditioning
• Many of our fears and anxieties may have
been classically conditioned.
• A phobia is an irrational fear of an activity,
object, or situation that is out of proportion
to the actual danger it poses.
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Classical Conditioning
• If a potential attitude object (CS) such as a
particular make of car is repeatedly paired with a
UCS that is either positive or negative, an
attitude is likely to form.
• Motives that are acquired through the process of
classical conditioning are called learned
motives.
• Many of the goals and incentives that motivate
our behavior are learned through classical
conditioning; hence they are termed learned
goals (incentives).
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5-17
Classical Conditioning
• Our understanding of classical conditioning has
been subject to revision since Pavlov introduced
the basic processes.
• One principle that has emerged from this
continued research is that the better the CS
predicts the occurrence of the UCS, the stronger
the conditioning will be.
• Blocking is a situation in which the
conditionability of a CS is weakened when it is
paired with a UCS that has previously been
paired with another CS.
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Classical Conditioning
• Previous trials of a CS-UCS pairing can serve to
block the effectiveness of a second CS.
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Classical Conditioning
• Taste-aversion learning refers to the
development of a dislike or aversion to a
flavor or food that has been paired with
illness.
• Preparedness is the theory that
organisms are biologically ready or
prepared to associate certain CSs with
certain UCSs.
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5-20
Operant Conditioning
• In operant conditioning, also known as
instrumental conditioning, an organism operates
on its environment to produce a change.
• Edward Thorndike studied the behavior of hungry
animals by placing them in a small chamber he
called a puzzle box.
• The law of effect is Thorndike’s view that
reinforcers promote learning, whereas punishers
lead to the unlearning of responses.
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Operant Conditioning
• B. F. Skinner was strongly influenced by
Edward Thorndike, as well as by John B.
Watson’s behavioral view of psychology.
• Watson believed that if we could understand
how to predict and control behavior, we would
know all there was to know about psychology.
• Skinner therefore began to look for the stimuli
that control behavior.
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Operant Conditioning
• To isolate those effects, he developed a special testing
environment called an operant conditioning chamber,
which is usually referred to as a Skinner box.
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Operant Conditioning
• A reinforcer is an event or stimulus that
increases the frequency of the response that
it follows.
• Positive reinforcers are events or stimuli
such as food, water, money, and praise that
are presented after the target response
occurs.
• Negative reinforcers are events or stimuli
that are removed because a response has
occurred.
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Operant Conditioning
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Operant Conditioning
• A primary reinforcer is an event or
stimulus that has innate (that is, biological)
reinforcing properties; you do not have to
learn that such stimuli are reinforcers.
• A secondary reinforcer is a stimulus that
acquires reinforcing properties by being
associated with a primary reinforcer.
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Operant Conditioning
• Skinner coined the term operant
conditioning because the behaviors we
emit voluntarily operate on the
environment around us in some way.
• The resulting changes in the environment
determine what happens to a given target
behavior (response).
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Operant Conditioning
• Positive reinforcement occurs when a
target behavior (response) is followed by
presentation of a positive reinforcer, which
has the effect of making the behavior more
likely to occur in the future.
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Operant Conditioning
• Shaping is a form of operant conditioning
in which a desired response is taught by
reinforcement of successive responses
that more closely resemble the target
response.
• The Premack Principle, refers to an
operant conditioning technique in which
the opportunity to participate in a preferred
activity reinforces a less preferred activity.
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Operant Conditioning
• Negative reinforcement occurs when a
target behavior (response) is followed by
removal or reduction of a negative
reinforcer, which leads to an increase in
the frequency of the target behavior.
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Operant Conditioning
• Escape conditioning occurs when certain
stimuli, whose removal immediately after
the occurrence of a response, increase the
likelihood of that response.
• Avoidance conditioning occurs when a
behavior increases in frequency if it
prevents an aversive stimulus from
occurring.
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Operant Conditioning
• Extinction is a general term for the
reduction and elimination of behaviors.
• In classical conditioning, extinction occurs
when repeated presentation of the CS
alone leads to a reduction in the strength
of the CR.
• In operant conditioning, extinction occurs
when a behavior is no longer followed by a
reinforcer.
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Operant Conditioning
• Extinction burst means that a behavior
often increases once extinction begins
before it is finally eliminated.
• Bringing a behavior under stimulus control
means that a particular stimulus or signal
tells the participant that its responses will
be reinforced.
• A discriminative stimulus is a stimulus
or signal telling the participant that
responding will be reinforced.
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Operant Conditioning
• A preset pattern or plan for delivering reinforcement, a
schedule of reinforcement, is an important determinant
of behavior.
• Once a target response has been shaped, the
experimenter can arrange to have the reinforcer
delivered according to a specific schedule.
• When evaluating various schedules of reinforcement, the
two dimensions of interest are (1) rate of responding,
and (2) resistance to extinction. Each schedule can be
described in terms of these two characteristics.
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Operant Conditioning
• The most basic schedule of reinforcement
is continuous reinforcement, in which
the participant is given a reinforcer after
each target response occurs.
• In schedules of reinforcement that do not
involve the use of continuous
reinforcement, some responses are not
reinforced.
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Operant Conditioning
• The term intermittent (or partial)
reinforcement describes these
noncontinuous patterns of delivering
reinforcement.
• There are two main types of intermittent
schedules: ratio and interval.
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Operant Conditioning
• When a ratio schedule is in effect, the
number of responses determines whether
the participant receives reinforcement.
• When an interval schedule is in effect,
responses are reinforced only after a
certain interval of time has passed.
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Operant Conditioning
• Fixed-ratio (FR)
schedules require that a
set number of responses
be made before a
reinforcer is delivered.
• Variable-ratio (VR)
schedules require that the
participant perform
differing numbers of
responses to obtain a
reinforcer.
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Operant Conditioning
• With a fixed-interval (FI)
schedule, the time
interval is constant.
• The time interval changes
after each reinforcer is
delivered when a
variable-interval (VI)
schedule is used.
• Ratio schedules generally
produce higher rates of
responding than interval
schedules.
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Operant Conditioning
• Operant responses that are not reinforced each time
during training take much longer to extinguish than ones
that have received continuous reinforcement.
• This phenomenon is known as the partial
reinforcement effect.
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Operant Conditioning
• A punisher is a
stimulus that
produces a decrease
in responding and
may take the form of
presentation of a
stimulus or
termination of a
stimulus.
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Operant Conditioning
• Punishment is the process of using a
punisher to decrease the response rate.
• Punishment is not an especially effective
means of altering behavior.
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Cognitive and Social Perspectives
On Learning
• Observational learning (modeling) is
learning that occurs through watching and
imitating the behaviors of others.
• For almost five decades, researchers have
been accumulating correlational and
experimental evidence on the relation
between exposure to media violence and
real-life aggression.
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Bandura’s Bobo Doll Study
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Bobo Doll (II)
• Results: Observing the aggressive model increased the
frequency of aggressive acts in the experimental group
• Also: When the control group was led to believe that
aggressive behavior would lead to reinforcement, they
were able to imitate the aggressive model
• Implication: Even if we do not immediate imitate
aggressive acts, we are learning to do so, and can
demonstrate this knowledge when we believe it is to our
benefit to do so.
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Cognitive and Social Perspectives
On Learning
• The general conclusion from the
accumulated evidence is: Violent media is
causally related to short-term and longterm expressions of aggression.
• One of the consequences of this exposure
to media violence is desensitization, which
is a reduction in distress-related
physiological reactivity to observations or
thoughts of violence.
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Cognitive and Social Perspectives
On Learning
• Although there are major differences
between songs and visual media such as
television, research has established that
aggressive words can prime aggressive
thoughts, perceptions, and behavior,
hence the concern for the potential effects
of violent lyrics on songs.
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Cognitive and Social Perspectives
On Learning
• One of the keys to observational learning
appears to be that the participant identifies
with the person being observed.
• If we put ourselves in the other person’s
place for a moment, we are better able to
imagine the effects of the reinforcer or
punisher.
• This phenomenon is called vicarious
reinforcement or vicarious punishment.
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