1 learning learning relatively permanent change in an organism’s behavior due to experience
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1
Learning
Learning relatively
permanent change in an organism’s behavior due to experience
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How Do We Learn?
We learn by association. Our minds naturally connect events that occur in
sequence.
2000 years ago, Aristotle suggested this law of association. Then 200 years ago Locke
and Hume reiterated this law.
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Association
We learn by association Our minds naturally connect events that occur
in sequence Aristotle 2000 years ago John Locke and David Hume 200 years ago
Associative Learning learning that two events occur together
two stimuli a response and its consequences
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Association
Learning to associate two events
Event 1 Event 2
Sea snail associates splash with a tail shock
Seal learns to expect a snack for its showy antics
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Classical or Pavlovian Conditioning
We learn to associate two stimuli
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Operant Conditioning
We learn to associate a response and its consequence
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Classical Conditioning
Classical Conditioning organism comes to associate two
stimuli a neutral stimulus that signals an
unconditioned stimulus begins to produce a response that anticipates and prepares for the unconditioned stimulus
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Ideas of classical conditioning originate from old philosophical theories. However, it was the Russian
physiologist Ivan Pavlov who elucidated classical conditioning. His work provided a basis for later behaviorists like John Watson and B. F. Skinner.
Classical Conditioning
Ivan Pavlov (1849-1936)
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Ivan Pavlov
Classical conditioning Experiments on dogs
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Classical Conditioning and Pavlov’s Dogs: Hypothesis
• Dogs salivate when food is placed in their mouths
• Dogs salivate at mere sight of food
• Hypothesis: Dogs can be trained, or conditioned, to salivate when exposed to an external stimulus
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Pavlov’s Experiments
Before conditioning, food (Unconditioned Stimulus, US) produces salivation (Unconditioned
Response, UR). However, the tone (neutral stimulus) does not.
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Pavlov’s Experiments
During conditioning, the neutral stimulus (tone) and the US (food) are paired, resulting in
salivation (UR). After conditioning, the neutral stimulus (now Conditioned Stimulus, CS) elicits
salivation (now Conditioned Response, CR)
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Pavlov’s Methodology and Results
Harness dog and place tube to collect saliva
Present external stimulus (bell) immediately before giving food
Results: After a few trials, the dog salivates upon hearing the bell
Works with other stimuli as well
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Pavlov’s Conclusions
Unconditioned Response
(UCR)
Unconditioned Stimulus (UCS)
Conditioned Response
(CR)
Conditioned Stimulus
(CS)
because of because of
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Pavlov’s Classic ExperimentBefore Conditioning
During Conditioning After Conditioning
UCS (foodin mouth)
Neutralstimulus(tone)
Nosalivation
UCR (salivation)
Neutralstimulus(tone)
UCS (foodin mouth)
UCR(salivation)
CS(tone)
CR (salivation)
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Classical Conditioning
UNCONDITIONED STIMULUS REFLEX ACTIONwill
elicit a
UNCONDITIONED STIMULUS
NEUTRAL STIMULUSREFLEX ACTIONwill
elicit a
CONDITIONED STIMULUSCONDITIONED STIMULUSwill
elicit aCONDITIONED
RESPONSE
NEUTRAL STIMULUSwill
elicit NO REACTION
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Classical Conditioning
Unconditioned Stimulus (UCS) stimulus that unconditionally--automatically
and naturally--triggers a response
Unconditioned Response (UCR) unlearned, naturally occurring response to the
unconditioned stimulus salivation when food is in the mouth
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Classical Conditioning Conditioned Stimulus (CS)
originally irrelevant stimulus that, after association with an unconditioned stimulus, comes to trigger a conditioned response
Conditioned Response (CR) learned response to a previously neutral
conditioned stimulus
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Continuing Pavlov’s Experiment
Acquisition Extinction Spontaneous
Recovery Generalization Discrimination
Other Aspects of Classical Conditioning
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Classical Conditioning
Acquisition the initial stage in classical conditioning the phase associating a neutral stimulus with
an unconditioned stimulus so that the neutral stimulus comes to elicit a conditioned response
in operant conditioning, the strengthening of a reinforced response
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Acquisition
Acquisition is the initial stage in classical conditioning in which an association between a neutral stimulus and an unconditioned stimulus
takes place.
1. In most cases, for conditioning to occur, the neutral stimulus needs to come before the unconditioned stimulus.
2. The time in between the two stimuli should be about half a second.
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Acquisition
The CS needs to come half a second before the US for acquisition to occur.
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Classical Conditioning
Extinction diminishing of a CR in classical conditioning, when a
UCS does not follow a CS in operant conditioning, when a
response is no longer reinforced
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Extinction
When the US (food) does not follow the CS (tone), CR (salivation) begins to decrease and
eventually causes extinction.
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Spontaneous Recovery
After a rest period, an extinguished CR (salivation) spontaneously recovers, but if the CS (tone) persists
alone, the CR becomes extinct again.
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Stimulus Generalization
Tendency to respond to stimuli similar to the CS is
called generalization. Pavlov conditioned the dog’s
salivation (CR) by using miniature vibrators (CS) on
the thigh. When he subsequently stimulated other parts of the dog’s
body, salivation dropped.
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Stimulus Discrimination
Discrimination is the learned ability to distinguish between a conditioned stimulus and other stimuli that
do not signal an unconditioned stimulus.
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Extending Pavlov’s Understanding
Pavlov and Watson considered consciousness, or mind, unfit for the scientific study of
psychology. However, they underestimated the importance of cognitive processes and
biological constraints.
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Cognitive Processes
Early behaviorists believed that learned behaviors of various animals could be reduced
to mindless mechanisms.
However, later behaviorists suggested that animals learn the predictability of a stimulus, meaning they learn expectancy or awareness
of a stimulus (Rescorla, 1988).
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Biological Predispositions
Pavlov and Watson believed that laws of learning were similar for all animals. Therefore,
a pigeon and a person do not differ in their learning.
However, behaviorists later suggested that learning is constrained by an animal’s biology.
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Biological Predispositions
John Garcia
Garcia showed that the duration between the CS and the US may be
long (hours), but yet result in conditioning. A biologically adaptive
CS (taste) led to conditioning and not to others (light or sound).
Courtesy of John G
arcia
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Biological Predispositions John Garcia
Conditioned taste aversions Not all neutral stimuli can become
conditioned stimuli. Internal stimuli—associate better with taste External stimuli—associate better with pain Biological preparedness
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Cognitive Processes
Conditioning occurs best when the CS and UCS have just the sort of relationship that would lead a scientist to conclude that the CS causes the UCS. — even in classical conditioning, it is not only the simple stimulus-response association but also the thought that counts.
Conditioning in advertising
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Nausea Conditioning in Cancer PatientsUCS(drug)
UCR(nausea)
CS(waiting room)
CS(waitingroom) CR
(nausea)
UCS(drug)
UCR(nausea)
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Pavlov’s greatest contribution to psychology is isolating
elementary behaviors from more complex ones through
objective scientific procedures.
Pavlov’s Legacy
Ivan Pavlov(1849-1936)
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Watson used classical conditioning procedures to
develop advertising campaigns for a number of
organizations, including Maxwell House, making the “coffee break” an American
custom.
Applications of Classical Conditioning
John B. Watson
Brow
n Brothers
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1. Alcoholics may be conditioned (aversively) by reversing their positive-associations with alcohol.
2. Through classical conditioning, a drug (plus its taste) that affects the immune response may cause the taste of the drug to invoke the immune response.
Applications of Classical Conditioning
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Operant & Classical Conditioning
1. Classical conditioning forms associations between stimuli (CS and US). Operant conditioning, on the other hand, forms an association between behaviors and the resulting events.
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Operant & Classical Conditioning
2. Classical conditioning involves respondent behavior that occurs as an automatic response to a certain stimulus. Operant conditioning involves operant behavior, a behavior that operates on the environment, producing rewarding or punishing stimuli.
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Behaviorism
John B. Watson
viewed psychology as objective science generally agreed-upon
consensus today
recommended study of behavior without reference to unobservable mental processes not universally accepted by all
schools of thought today
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John Watson and Rosalie Rayner: Hypothesis, Methodology, Results
After a few tries, Albert was afraid of the rat
+ =
Conditioned fear into an infant
Presented a rat immediately followed by a loud noise, startling the baby
Albert generalized his fears to other furry objects
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Watson & Raynor with Little Albert
Watson took a a baby named Albert and conditioned him to be afraid of white furry objects using Pavlov’s techniques.
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Conditioned fear experiments such as Albert’s experience would never occur
today because of the existing ethical
standards.
Conditional Training: Albert and Peter
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Mary Cover Jones• In 1925, Mary Cover Jones (a colleague of Watson) hypothesized
that she would be able to decondition a three-year-old boy named Peter from some of his fears, which included feathers, cotton, frogs, fish, rats, rabbits, and mechanical toys. She began by bringing a caged rabbit into the same room where Peter was having a snack in his highchair. The rabbit was far enough away that it did not bother Peter. The next day, she brought the rabbit increasingly closer to Peter until he began to become disturbed. On subsequent days, the rabbit was moved closer and closer to Peter’s highchair only to the point at which Peter became afraid, at which time they’d end the experiment for the day. Eventually, Peter was able to pet the rabbit, having been deconditioned from his fear. Jones was able to decondition most of Peter’s other fears in this manner.
• Watson and Rayner’s experiment with Little Albert showed that people can be conditioned to fear specific types of objects. Conversely, Jones suggested that people could be deconditioned from their fears. Similar methods are used today to help people overcome phobias.
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Mary Cover Jones used an early form of desensitization to prove that fears (phobias) could be unlearned.
Peter, a young boy, had an extreme fear of rabbits. Jones gave Peter his favorite food while slowly bringing the rabbit closer and closer. Eventually Peter no longer panicked around rabbits.
Mary Cover Jones
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Mary Cover Jones• Colleague of Watson• Deconditioned 3-year-old Peter from his fears by
gradually moving a rabbit (and other things) closer to him while he was eating
DAY 1 DAY 3DAY 2
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Operant Conditioning
Operant Conditioning type of learning in which behavior is
strengthened if followed by reinforcement or diminished if followed by punishment
Law of Effect Thorndike’s principle that behaviors followed
by favorable consequences become more likely, and behaviors followed by unfavorable consequences become less likely
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Operant Conditioning
Operant Behavior operates (acts) on environment produces consequences
Respondent Behavior occurs as an automatic response to
stimulus behavior learned through classical
conditioning
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Early Operant Conditioning
E. L. Thorndike (1898)Puzzle boxes and cats
Scratch at bars
Push at ceiling
Dig at floorSituation:stimuliinside ofpuzzle box
Howl
Etc.
Etc.
Press lever
First Trialin Box
Scratch at bars
Push at ceiling
Dig at floorSituation:stimuliinside ofpuzzle box
Howl
Etc.
Etc.
Press lever
After ManyTrials in Box
55Edward L. Thorndike ( 1874–1949)
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Skinner’s ExperimentsSkinner’s experiments extend Thorndike’s thinking,
especially his law of effect. This law states that rewarded behavior is likely to occur again.
Yale U
niversity Library
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Operant Chamber
Using Thorndike's law of effect as a starting point, Skinner developed the Operant chamber,
or the Skinner box, to study operant conditioning.
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B.F. Skinner and Operant Conditioning
Classical conditioning involves an automatic response to a stimulus
Operant conditioning involves learning how to control one’s response to elicit a reward or avoid a punishment
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Operant Conditioning
B.F. Skinner (1904-1990) elaborated
Thorndike’s Law of Effect
developed behavioral technology
60B. F. Skinner (1904–1990)
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The “Skinner Box”: Skinner’s Hypothesis, Methodology, and Results
Rats placed in “Skinner boxes”
Shaped to get closer and closer to the bar in order to receive food
Eventually required to press the bar to receive food
Food is a reinforcer
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Operant Chamber
The operant chamber, or Skinner box, comes with a bar or key that
an animal manipulates to obtain a reinforcer
like food or water. The bar or key is connected to devices that record the animal’s response.
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Shaping
Shaping is the operant conditioning procedure in which reinforcers guide behavior towards the desired target behavior through successive
approximations.
A rat shaped to sniff mines. A manatee shaped to discriminateobjects of different shapes, colors and sizes.
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Types of Reinforcers
Any event that strengthens the behavior it follows. A heat lamp positively reinforces a
meerkat’s behavior in the cold.
Reuters/ C
orbis
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Operant Conditioning
Positive Reinforcement any event that
strengthens the
behavior it follows
Negative Reinforcement The removal of a punishment or an
aversive stimulus It STRENGTHENS behavior
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Negative Reinforcement and Punishment
Negative reinforcement: Removing an unpleasant stimulus
Punishment
1. Unpleasant stimulus
2. Removal of unpleasant stimulus
=
=
1. Introducing an unpleasant stimulus
2. Withholding a pleasant stimulus
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Figure 6.18 Positive reinforcement versus negative reinforcement
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Figure 6.20 Comparison of negative reinforcement and punishment
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Operant Conditioning
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1. Primary Reinforcer: An innately reinforcing stimulus like food or drink.
2. Conditioned Reinforcer (secondary reinforcer): A learned reinforcer that gets its reinforcing power through association with the primary reinforcer.
Primary & Secondary Reinforcers
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1. Immediate Reinforcer: A reinforcer that occurs instantly after a behavior. A rat gets a food pellet for a bar press.
2. Delayed Reinforcer: A reinforcer that is delayed in time for a certain behavior. A paycheck that comes at the end of a week.
Immediate & Delayed Reinforcers
We may be inclined to engage in small immediate reinforcers (watching TV) rather than large delayed reinforcers (getting an A in a course) which require
consistent study.
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Reinforcement Schedules
1. Continuous Reinforcement: Reinforces the desired response each time it occurs.
2. Partial Reinforcement: Reinforces a response only part of the time. Though this results in slower acquisition in the beginning, it shows greater resistance to extinction later on.
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Rates and Types of Reinforcement:
Additional ExperimentsFixed-ratio: food given after a fixed number of responses
Variable-ratio: number of responses required to get food changes each time
Fixed-interval: food given after a certain amount of time elapses
Variable-interval: amount of time required to get food changes each time
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Schedules of Reinforcement
Fixed Ratio (FR) reinforces a response only after a
specified number of responses faster you respond the more rewards you
get different ratios very high rate of responding like piecework pay
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Schedules of Reinforcement
Variable Ratio (VR) reinforces a response after an
unpredictable number of responses average ratios like gambling, fishing very hard to extinguish because of
unpredictability
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Schedules of Reinforcement
Fixed Interval (FI) reinforces a response only after a
specified time has elapsed response occurs more frequently as
the anticipated time for reward draws near
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Schedules of Reinforcement
Variable Interval (VI) reinforces a response at unpredictable
time intervals produces slow steady responding like pop quiz
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Schedules of Reinforcement
Variable Interval
Number of responses
1000
750
500
250
010 20 30 40 50 60 70
Time (minutes)
Fixed Ratio
Variable Ratio
Fixed Interval
Steady responding
Rapid respondingnear time forreinforcement
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Punishment
Punishment aversive event that decreases the
behavior that it follows powerful controller of unwanted
behavior
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Punishment
An aversive event that decreases the behavior it follows.
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Punishment
1. Results in unwanted fears.2. Conveys no information to the organism.3. Justifies pain to others.4. Causes unwanted behaviors to reappear in its
absence.5. Causes aggression towards the agent.6. Causes one unwanted behavior to appear in
place of another.
Although there may be some justification for occasional punishment (Larzelaere & Baumrind,
2002), it usually leads to negative effects.
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Updating Skinner’s Understanding
Skinner’s emphasis on external control of behavior made him an influential, but controversial figure. Many psychologists criticized Skinner for underestimating the importance of cognitive and biological constraints.
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Cognition & Operant Conditioning
Evidence of cognitive processes during operant learning comes from rats during a maze
exploration in which they navigate the maze without an obvious reward. Rats seem to
develop cognitive maps (E.C. Tolman), or mental representations, of the layout of the maze
(environment).
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Cognitive Approach
This approach emphasizes abstract and subtle learning that could not be achieved through conditioning or social learning alone.
Some learning is not intentional, but occurs almost accidentally—a situation called latent learning. Learning that occurs, but is not apparent until there is an incentive to demonstrate it
Expectancies are beliefs about our ability to perform an action and to get the desired reward. Expectancies affect learning.
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Latent Learning
Such cognitive maps are based on latent learning, which becomes apparent when an incentive is given (Tolman & Honzik, 1930).
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Cognition and Operant Conditioning
Overjustification Effect the effect of promising a reward for
doing what one already likes to do the person may now see the reward,
rather than intrinsic interest, as the motivation for performing the task
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Motivation
Intrinsic Motivation: The desire to perform a behavior for its own sake.
Extrinsic Motivation: The desire to perform a behavior due to promised rewards or threats of punishments.
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Biological Predisposition
Biological constraints predispose organisms to learn associations that are naturally adaptive.Breland and Breland (1961) showed that
animals drift towards their biologically
predisposed instinctive behaviors.
Marian Breland Bailey
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Skinner’s Legacy
Skinner argued that behaviors were shaped by external influences instead of inner thoughts and
feelings. Critics argued that Skinner dehumanized people by neglecting their free will.
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Skinner’s ImportanceEducation: programmed instruction
Work
Parenting Personal goals
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Applications of Operant Conditioning
Skinner introduced the concept of teaching machines that shape learning in small steps and
provide reinforcements for correct rewards.
In School
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Applications of Operant Conditioning
Reinforcement principles can
enhance athletic performance.
In Sports
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Applications of Operant Conditioning
Reinforcers affect productivity. Many companies now allow employees to share profits and
participate in company ownership.
At work
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Applications of Operant Conditioning
In children, reinforcing good behavior increases the occurrence of these behaviors. Ignoring
unwanted behavior decreases their occurrence.
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Operant vs. Classical Conditioning
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Observational Learning
Observational Learning (Albert Bandura) learning by observing and imitating others
Modeling process of observing and imitating a
specific behavior Prosocial Behavior
positive, constructive, helpful behavior opposite of antisocial behavior
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Bandura's Experiments
Bandura's Bobo doll study (1961) indicated
that individuals (children) learn through
imitating others who receive rewards and
punishments.
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Albert Bandura: Hypothesis
• Believed we learn through observation and imitation• Hypothesized that children would imitate aggressive
behavior they observed
=
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Bandura’s Methodology
• Children watched films of adults beating Bobo dolls• Three groups: aggression-rewarded, aggression-
punished, no consequences• Children went into rooms with toys that they were told
not to play with
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Bandura’s Results
• Children in the aggression-punished group expressed the fewest aggressive behaviors toward the Bobo dolls
• Children in the other two groups expressed an equal number of aggressive behaviors and were more aggressive than children in the aggression-punished group
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Bandura’s Experiment
• Children promised rewards for imitating the adult in the film
• Now, all three groups were equally aggressive
• Children had learned the aggressive behavior from the film, but those who saw the adults being punished were less likely to act aggressively
Viewing aggressive behavior
Rewards for imitation Aggressive behavior
+=
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Bandura’s Social Learning Theory
• Relates to effects of violence and other images on TV and in the movies
• Children imitate good and neutral behaviors as well as bad ones
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This series of photographs shows children observing and modeling aggressive behavior.
Albert Bandura’s Bobo Doll Experiment
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Positive Observational Learning
Fortunately, prosocial (positive, helpful) models may have prosocial effects.
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Applications of Observational Learning
Unfortunately, Bandura’s studies
show that antisocial models (family,
neighborhood or TV) may have antisocial
effects.
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Learning by Observation
Higher animals, especially humans,
learn through observing and imitating others.
The monkey on the right imitates the monkey on the left in touching the
pictures in a certain order to obtain a
reward.
© H
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©H
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Mirror Neurons
Neuroscientists discovered mirror neurons in the brains of animals and humans that are active
during observational learning.
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Imitation Onset
Learning by observation begins early in life. This
14-month-old child imitates the adult on TV
in pulling a toy apart.
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Television and Observational Learning
Gentile et al., (2004) shows that children in
elementary school who are exposed to violent television, videos, and video games express increased aggression.
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Modeling Violence
Research shows that viewing media violence leads to an increased expression of aggression.
Children modeling after pro wrestlers
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Do what I say, not what I do—
This will teach you to hit your brother—
Why do you do that, you know you get in trouble for it—
Famous last words???
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