Download Operant Conditioning

Behavioral Learning Theory
Aws Khasawneh, MD.
Learning is:
 The acquisition of new behavior patterns.
 A persisting change in human performance or performance
potential . (brought) about as a result of the learner’s
interaction with the environment.
 the relatively permanent change in a person’s knowledge or
behavior due to experience.
 Behaviorists say that a person’s behavior is determined by
adaptive and maladaptive learning.
 Learning methods are the basis of behavioral treatment
techniques.
Learning Mechanisms:
A) Simple forms:
- Habituation: Repeated stimulation results in a decreased
response(a child who receives weekly allergy injections cries
less and less with each injection)
- Sensitization: Repeated stimulation results in an
increased response(a child who is afraid of spiders feels more
anxiety each time he encounters spider)
B) Complex forms:
- Classical Conditioning.
- Operant Conditioning.
Classical Conditioning
CLASSICAL CONDITIONING
A. Principles

In classical conditioning, a natural or reflexive response (behavior) is
elicited by a learned stimulus (a cue from an internal or external
event). This type of learning is called associative learning.
Key Definitions
 Unconditioned Stimulus (US) - stimulus naturally triggers a
response
 Unconditioned Response (UR) - unlearned (natural),
reflexive response (behavior) to the UCS
 Conditioned Stimulus (CS) – stimulus that produce a
response following learning ( initially neutral)
 Conditioned Response (CR) – is a behavior (response) that is
learned by an association between a conditioned stimulus and
unconditioned stimulus.
Ivan Pavlov
 Russian physiologist studying
the digestive system
 Focusing on what substance
helped to break food down
 One notable substance studied
was saliva
 Developed method to
measure saliva production
Salivary Conditioning Apparatus
Process of Pavlov’s Saliva Research
 Dog given food and salivation was recorded while the dog
ate
 Key finding: Experienced dogs salivated before the food was
presented
 Pavlov’s Theory: Some stimulus (e.g. experimenter;
apparatus) that proceeded food presentation had acquired
capacity to elicit the response of salivation
 What was happening? Dogs were exhibiting a type of
learning
 This type of learning is the foundation of Classical
Conditioning
Paradigm of Classical Conditioning
 1st: Select a stimulus that reliably elicits a characteristic
response
 Stimulus – Unconditioned stimulus (US)
 Response -- Unconditioned response (UR)
 Unconditioned - Signifies the US - UR connection is unlearned (innate)
 2nd: Select a Stimulus for Conditioning (CS)
 CS – Can be any reasonable stimulus that does not initially
evoke the UR

Conditioned – Signifies that CS will only elicit desired response after
conditioning take place
Pavlov’s Dogs
 Before Conditioning
 US (Food)  UR (Salivation)
 CS (Bell)  No CR; Dog may turn head (orienting response)
 During Conditioning
 CS paired/presented consistently before US
Time                
 CS (Bell)  US (Food)  UR (Salivation)
 As presentations continue:
 CS (Bell)  CR (Salivation)  US (Food) UR (Salivation)
 After Conditioning
 US (Food)  UR (Salivation)
 CS (Bell)  CR (Salivation)
Extinction
 The CR decreases if the CS is never again paired with the
US.
 Passage of time does not cause animals to “forget” to
produce the CR in presence of CS
 Repeatedly present CS without the US, will eventually lose
CR
Spontaneous Recovery
 Even though no CRs present after one day of extinction
trials, CR is present the following day
 Time is key factor
 More time between 1st and 2nd extinction session, more
spontaneous recovery observed
Rapid Reacquisition
 Acquisition phase  extinction phase  acquisition
phase (i.e. reacquisition phase)
 Rate of learning is faster
 Repeated Cycles continues to get faster
Generalization and Discrimination
 Generalization: Transfer of effects of conditioning to similar
stimuli
 In general, the more similar a stimulus is to training stimulus,
the greater its capacity to elicit a CR
 Discrimination: Subject learns to respond to one stimulus,
but not to a similar stimulus
 J.B. Watson: “suggested…that human emotions might profitably
be thought of as glandular and muscular reflexes which, like
salivation, easily become conditioned”
 With Little Albert, Watson was able to demonstrate that the
acquisition of a phobia (an exaggerated, seemingly illogical fear
of a particular object or class of objects) could be explained by
classical conditioning
Little Albert
 [Little] Albert, eleven months of age, was an infant, afraid of nothing “under the
sun” except a loud sound made by striking a steel bar. This made him cry. By
striking the bar at the same time that Albert touched a white rat, the fear
transferred to the white rat. After seven combined stimulations, rat and sound,
Albert not only became greatly disturbed at the sight of a rat, but this fear had
spread to include a white rabbit, cotton, wool, a fur coat, [a dog, a Santa Claus
mask, and the experimenter’s hair. It did not transfer to his wooden blocks and
other objects very dissimilar to the rat.
Applications in Behavioral Therapy
1- Systematic Desensitization for Phobia
is a treatment for phobias in which the individual is trained to relax
while being exposed to progressively more anxiety-provoking stimuli.
 Phobia: Excessive and irrational fear of an object, place, or
situation,Example: Spiders, Closed-Spaces, and Crowds
2- Aversion therapy: is a type of behavior therapy designed to
encourage individuals to give up undesirable habits by causing
them to associate the habit with an unpleasant effect.
3- Flooding: is a form of desensitization that uses repeated exposure
to highly distressing stimuli until the lack of reinforcement of the
anxiety response causes its extinction.
A grade school principal has 1 week to try out a new fire-alarm system for the
school. He decides to test the system three times during the week. The first
time the alarm is sounded, all of the students leave the school within 5
minutes. The second time, it takes the students 15 minutes to leave the school.
The third time the alarm is sounded, the students ignore it. The students'
response to the fire alarm the third time it is sounded is most likely to have
been learned by
A. sensitization
B. habituation
C. classical conditioning
Operant Conditioning
OPERANT CONDITIONING
A. Principles
 For an individual, behavior is determined by its consequences. The
consequence (re-enforcement or punishment) occurs immediately
following a behavior.
 The Skinner experiment
Operant Conditioning
 Theorist
 B. F. Skinner
 Original research
 Rats in Skinner boxes
Skinner Box
Differences between
Classical Conditioning and
Operant Conditioning
Classical Conditioning
 Simple/Reflex Behavior
Operant Conditioning
 Complex/Voluntary Behavior
 Focuses on ANTECEDENTS:  Focuses On
Events which take place
BEFORE the target response
 Learning takes place when
CONSEQUENCES: Events
which take place AFTER the
target response
there is an association made  Learning takes place when a
between two unrelated stimuli desired (target) response is
affected by its consequences
(before the desired / target
(after the desired/target
response)
response)
Operant Conditioning Concepts
 Positive reinforcement (reward)
 Strengthening (increasing) a behavior by presenting a positive
stimulus immediately after the behavior has occurred
 Negative reinforcement ( escape, avoidance)
 Strengthening (increasing) a behavior by removing a negative
stimulus immediately after the behavior has occurred
Operant Conditioning Concepts
 punishment: the introduction of aversive stimulus after
behavior aimed at reduced the rate of that behavior.
Operant Conditioning Concepts
 Extinction
 When a previously reinforced behavior decreases in frequency
and eventually ceases altogether because reinforcement is
withheld
 Spontaneous recovery
 When an extinguished behavior reappears without having been
reinforced
Example: A mother would like her 8-year-old son to stop hitting his 6-year-old brother. She can
achieve this goal by using one of the following features of operant conditioning:
Feature
Effect on behavior
Example
Comment
Positive reinforcement
Behavior is increased by reward
Child increases his kind behavior
toward his younger brother to get a
praise from his mother
Reward or reinforcement
(praise) increases desired behavior
(kindness toward brother)
A reward can be praise or attention as
well as a tangible reward like money
Negative reinforcement
Behavior is increased by avoidance
or escape
Child increases his kind behavior
toward his younger brother to avoid
being scolded
Active avoidance of an
aversive stimulus (being
scolded) increases desired behavior
(kindness toward brother)
Punishment
Behavior is decreased by
suppression
Child decreases his hitting behavior
after mother scolds him
Delivery of an aversive
stimulus (scolding)
decreases unwanted
behavior (hitting brother)
rapidly but not permanently
Extinction
Behavior is eliminated by non
reinforcement
Child stops his hitting behavior
when the behavior is ignored by his
mother
Extinction is more effective
than punishment for
long-term reduction in
unwanted behavior
There may be an initial
increase in hitting behavior
before it disappears
Operant Conditioning Concepts
 Shaping
 Reducing complex behaviors into several more simple behaviors
 Reinforcing successive approximations to the complex behavior
 Modeling: type of observational learning in which individual
behaves in a manner similar to that of someone she/he admires
Schedules of Reinforcement
 Continuous: Reinforcement presented after every response.( rapidly
learned but has little resistance to extinction/ disappears rapidly.)
 E.g. A teenager receives a candy bar each time she puts a dollar into a vending
machine. One time she puts a dollar in and nothing comes out. She never buys candy
from the machine again.
 Fixed interval schedule
 Reinforcement occurs after a specific amount of time.( the response
rate increases toward the end of each interval)
 . E.g. A student has an anatomy quiz every Friday. He studies for 10
minutes on Wednesday nights, and for 2 hours on Thursday nights.
 Fixed ratio schedule
 Reinforcement occurs after a specific number of responses.( fast
response rate)
 E.g. - A man is paid $10 for every five hats he makes. He makes as
many hats as he can during his shift.
 Variable interval schedule
 Reinforcement occurs after a random amount of time.( it is
highly resistant to extinction.)
 . E.g. After 5 minutes of fishing in a lake a man catches a large
fish. He then spends 4 hours waiting for another bite.
 Variable ratio schedule
 Reinforcement occurs after a random number of responses.
(highly resistant to extinction)
 . E.g. - After a slot machine pays off $5 for a single quarter, a
woman plays $50 in quarters despite the fact that she receives
no further payoffs.
Of all the reinforcement schedules, variable schedules
are the most resistant to extinction.
Applications of Operant Principles
 Behavior modification
 Shaping
 Token economies
 Contingency contracts
 Extinction, time-out, and response cost
 Punishment