Observational learning

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Matakuliah
Tahun
: O0072 / Pengantar Psikologi
: 2008
BASIC PRINCIPLES OF LEARNING
Pertemuan 4,5
DEFINITION OF LEARNING
• Any relatively permanent change in behavior brought
about through experiences – through interaction with
environment
• the acquisition and development of memories and
behaviors, including skills, knowledge, understanding,
values, and wisdom. It is the goal of education, and the
product of experience.
• Permanent vs. temporary
• Result of experiences vs. biological causes
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Types of Learning (1)
NON ASSOCIATIVE LEARNING
Habituation
–
–
–
There is a progressive diminution of behavioral response probability with repetition of a
stimulus.
It is another form of integration. An animal first responds to a stimulus, but if it is neither
rewarding nor harmful the animal reduces subsequent responses.
One example of this can be seen in small song birds - if a stuffed owl (or similar predator) is
put into the cage, the birds initially react to it as though it were a real predator. Soon the birds
react less, showing habituation. If another stuffed owl is introduced (or the same one
removed and re-introduced), the birds react to it as though it were a predator, showing that it
is only a very specific stimulus that is habituated to (namely, one particular unmoving owl in
one place).
Sensitization
–
–
The progressive amplification of a response follows repeated administrations of a stimulus
(Bell et al., 1995).
An everyday example of this mechanism is the repeated tonic stimulation of peripheral
nerves that will occur if a person rubs his arm continuously. After a while, this stimulation will
create a warm sensation that will eventually turn painful. The pain is the result of the
progressively amplified synaptic response of the peripheral nerves warning the person that
the stimulation is harmful. Sensitization is thought to underlie both adaptive as well as
maladaptive learning processes in the organism.
Imprinting
–
Any kind of phase-sensitive learning (learning occurring at a particular age or a particular life
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stage) that is rapid and apparently
independent
of the consequences of behavior.
Types of Learning
ASSOCIATIVE LEARNING
• Classical conditioning involves repeatedly pairing an unconditioned
stimulus (which unfailingly evokes a particular response) with
another stimulus (which does not normally evoke the response).
Following conditioning, the response occurs both to the
unconditioned stimulus and to the other, unrelated stimulus (now
referred to as the "conditioned stimulus"). The response to the
conditioned stimulus is termed a conditioned response
• Operant conditioning is the use of consequences to modify the
occurrence and form of behavior. Operant conditioning deals with
the modification of voluntary behavior
• Observational learning, The most basic learning process is imitation,
one's personal repetition of an observed process, such as a smile.
Thus an imitation will take one's time (attention to the details), space
(a location for learning), skills (or practice), and other resources (for
example, a protected area). Through copying, most infants learn
how to hunt (i.e., direct one's
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CLASSICAL CONDITIONING (1)
Pavlov presented dogs with food,
and measured their salivary
response (how much they
drooled). Then he began ringing a
bell just before presenting the
food. At first, the dogs did not
begin salivating until the food was
presented. After a while, however,
the dogs began to salivate when
the sound of the bell was
presented.
They learned to associate the
sound of the bell with the
presentation of the food. As far as
their immediate physiological
responses were concerned, the
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sound of the bell became
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CLASSICAL CONDITIONING (2)
terminology
• Unconditioned Stimulus (UCS)
– The stimulus that can elicit a response without any learning – inborn
– Ex. The meat – the food
• Unconditioned Response (UCR)
– An unlearn, inborn reaction to an unconditioned stimulus
– Ex. Saliva
• Conditioned Stimulus (CS)
– A stimulus that comes to elicit responses as a result of being paired with
an unconditioned stimulus
• Conditioned Response (CR)
– A response that is similar or identical to the unconditioned response that
comes to be elicited by a conditioned stimulus
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CLASSICAL CONDITIONING (3)
• A form of learning in which a previously neutral stimulus (CS) is
paired with an unconditioned stimulus (UCS) to elicit a conditioned
response (CR) that is identical to or very similar to unconditioned
response (UCR)
UCS
UCR
CS + UCS
UCR
CS
CR = UCR
http://en.wikipedia.org/wiki/Classical_conditioning
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CLASSICAL CONDITIONING (4)
Application
•
John B. Watson's Little Albert
– proposed that emotions (such as fear) can be conditioned in humans.
– To study this, Watson conditioned an eleven month old child, Albert, to fear a
various neutral objects (including a rabbit, a dog and some wool) by repetitively
pairing their presence with a loud noise. Resulted in little Albert displaying severe
fear responses to the previously un feared objects.
– The goal of Watson's experiment had been to prove that behavior is learned, in
contrast to the then-prevalent, Freudian belief that behavior came from the
unconscious.
•
Behavioral Therapies
– Aversion Therapy is designed to eliminate addictive behavior
• Aversion therapy is a form of psychiatric or psychological treatment in which
the patient is exposed to a stimulus while simultaneously being subjected to
some form of discomfort. This conditioning is intended to cause the patient
to associate the stimulus with unpleasant sensations, and to then stop a
certain behavior
– Systematic Desensitization
Patients might learn that the object of their phobias or fears are not so fearful if they can
safely relive the feared stimulus. However, anxiety often obstructs such recovery. This
obstruction is overcome by reintroducing the fear-producing object gradually by a
process known as reciprocal inhibitions. A person constructs a hierarchy of events
leading to the feared situation. This hierarchy is approached step by step and anxiety is
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eventually removed if the therapy is performed
OPERANT CONDITIONING (1)
• Learning in which the consequences of behavior lead to changes in
the probability of its occurrence
• Operant conditioning, sometimes called instrumental conditioning or
instrumental learning, was first extensively studied by Edward L.
Thorndike (1874-1949), who observed the behavior of cats trying to
escape from home-made puzzle boxes
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OPERANT CONDITIONING (2)
The Skinner Box
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OPERANT CONDITIONING (3)
The four procedures
•
Positive reinforcement occurs when a behavior (response) is followed by a favorable
stimulus (commonly seen as pleasant) that increases the frequency of that behavior.
–
•
Negative reinforcement occurs when a behavior (response) is followed by the
removal of an aversive stimulus (commonly seen as unpleasant) thereby increasing
that behavior's frequency.
–
•
In the Skinner box experiment, negative reinforcement can be a loud noise continuously
sounding inside the rat's cage until it engages in the target behavior, such as pressing a
lever, upon which the loud noise is removed.
Positive punishment (also called "Punishment by contingent stimulation") occurs
when a behavior (response) is followed by an aversive stimulus,
–
•
In the Skinner box experiment, a stimulus such as food or sugar solution can be delivered
when the rat engages in a target behavior, such as pressing a lever.
such as introducing a shock or loud noise, resulting in a decrease in that behavior.
Negative punishment (also called "Punishment by contingent withdrawal") occurs
when a behavior (response) is followed by the removal of a favorable stimulus,
–
such as taking away a child's toy following an undesired behavior, resulting in a decrease in
that behavior.
http://en.wikipedia.org/wiki/Operant_conditioning
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OPERANT CONDITIONING (4)
Positive Reinforcement
•
2 important issues
1.
Timing : must be given within a short time following the response
–
2.
•
Consistency in the delivery of reinforcement
Primary & Secondary Reinforcement
–
–
•
Delay of reinforcement : the passage of time between the response and the positive
reinforcement that leads to reduced efficiency of operant conditioning
Primary : innate positive reinforcers that do not have to be acquired through
learning
Secondary : learned positive reinforcers
Schedules of Positive Reinforcement
1.
2.
3.
4.
Fix ratio : a reinforcer is given only after a specified number of responses
Variable ratio : a reinforcer is given only after a varying number of responses
Fix interval : a reinforcer is given following the 1st response occurring after a
predetermined period of time
Variable interval : a reinforcer is given following the 1st response occurring after
a variable amount of time
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OPERANT CONDITIONING (5)
Positive Reinforcement
• Shapping – the methods of
successive approximations
– A strategy of positively reinforcing
behaviors that are successively
more similar to desired behaviors
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OPERANT CONDITIONING (6)
Negative Reinforcement
•
Occurs when
1. A behavior is followed by the removal or the avoidance of
negative event
2. The probability that the behavior will occur in the future
increases as a result
•
2 types of conditioning
1. Escape conditioning
– The behavior is reinforced because it causes a negative event to
cease
2. Avoidance Conditioning
– The behavior is reinforced because it prevents something negative
from happening
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OPERANT CONDITIONING (7)
Punishment
•
A negative consequence of behavior, which leads to a decrease in
the frequency of the behavior that produces it
•
5 dangers :
1. The use of punishment is often reinforcing to the punisher
2. Punishment often has a generalized inhibiting effects on the individual
3. We commonly react to physical punishment by learning to dislike the
person who inflicts the pain and perhaps by reacting aggressively
toward that person
4. Criticism trap : an increase in the frequency of a (-) behavior that often
follows the use of the criticism, reinforcing the behavior it is intended to
punish
5. It does not teach the individual how to act more appropriately
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OBSERVATIONAL LEARNING (1)
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OBSERVATIONAL LEARNING (2)
vicarious learning or social learning
• is learning that occurs as a function of observing,
retaining and replicating behavior observed in others.
• It is most associated with the work of psychologist Albert
Bandura, who implemented some of the seminal studies
in the area and initiated social learning theory.
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OBSERVATIONAL LEARNING (3)
Four conditions required for a person to successfully model the behaviour of
someone else:
1. Attention to the model
– A person must first pay attention to a person engaging in a certain behavior (the
model).
2. Retention of details
– Once attending to the observed behavior, the observer must be able to
effectively remember what the model has done.
3. Motor reproduction
– The observer must be able to replicate the behavior being observed. For
example, juggling cannot be effectively learned by observing a model juggler if
the observer does not already have the ability to perform the component actions
(throwing and catching a ball).
4. Motivation and Opportunity
– The observer must be motivated to carry out the action they have observed and
remembered, and must have the opportunity to do so. For example, a suitably
http://en.wikipedia.org/wiki/Observational_learning
skilled person must want to replicate the behavior of a model juggler, and needs
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to have an appropriate number
items to juggle at hand.
EXTINCTION
• The process of unlearning a learned response because of the
removal of the original source of learning
≠ Partial reinforcement effect
the phenomenon that responses that have been reinforced on variable ratio or variable interval
schedules are more difficult to extinguish that responses that have been continuously reinforced
≠ Response prevention
the prevention of avoidance responses to ensure that the individual sees that the negative
consequences will not occur to speed up the extinction of avoidance responses
≠ Spontaneous recovery
a temporary increase in the strength of a CR, which is likely to occur during extinction after the
passage of time
≠ Disinhibition
a temporary increase in the strength of a extinguished response caused by an unrelated stimulus
event
≠ Operant Extinction
the awakening and eventual disapperance of a response because it is no longer reinforced
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THEORETICAL INTEPRETATION OF LEARNING
• Place learning
– Cognitive map : an inferred mental awareness of the structure of
physical space or related elements
• Latent learning
• Insight learning and learning sets
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