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Gazzaniga • Heatherton • Halpern
Psychological Science
FIFTH EDITION
Chapter 6
Learning
©2015 W. W. Norton & Company, Inc.
6.1 How Do We Learn?
Learning Objectives
• Define learning,
• Identify three types of learning processes.
• Describe the nonassociative learning
processes: habituation and sensitization.
Explain the significance of each.
Learning Results from Experience
• Learning: a relatively enduring change in
behavior, resulting from experience
– Associations develop through conditioning, a
process in which environmental stimuli and
behavioral responses become connected
Learning Results from Experience
• Learning theory arose in the early twentieth century
in response to Freudian and introspective
approaches.
– John B. Watson argued that only observable behavior was
a valid indicator of psychological activity, and that the
infant mind was a tabula rasa, or blank slate.
– He stated that the environment and its effects were the
sole determinants of learning.
• Behaviorism was the dominant paradigm into the
1960s, and it had a huge influence on every area of
psychology.
There Are Three Types of Learning
• Nonassociative learning: responding after
repeated exposure to a single stimulus, or
event
• Associative Learning: linking two stimuli, or
events, that occur together
• Observational: acquiring or changing a
behavior after exposure to another individual
performing that behavior
Habituation and Sensitization Are
Simple Models of Learning
• Habituation: a decrease in behavioral
response after repeated exposure to a
stimulus
– Especially if the stimulus is neither harmful nor
rewarding
• Dishabituation: an increase in a response
because of a change in something familiar
Habituation and Sensitization Are
Simple Models of Learning
• Sensitization: an increase in behavioral
response after exposure to a stimulus
– Stimuli that most often lead to sensitization are
those that are threatening or painful.
6.2 How Do We Learn Predictive
Associations?
Learning Objectives
• Define classical conditioning.
• Differentiate between US, UR, CS, and CR.
• Describe acquisition, extinction, spontaneous
recovery, generalization, discrimination, secondorder conditioning, and blocking.
• Describe the Rescorla-Wagner model of classical
conditioning, including the role of prediction error
and dopamine in the strength of associations.
• Describe the role of conditioning in the development
and treatment of phobias and addictions.
6.2 How Do We Learn Predictive
Associations?
• We learn predictive associations through
conditioning, the process that connects
environmental stimuli to behavior.
– Psychologists study two types of associative
learning.
• Classical conditioning
• Operant conditioning
Behavioral Responses Are Conditioned
• Watson was influenced by Ivan Pavlov’s
research on the salivary reflex, an automatic
response when food stimulus is presented to a
hungry animal.
– Pavlov won a Nobel Prize in 1904 for his research
on the digestive system.
• Pavlov noticed the dogs salivated as soon as
they saw the bowls that usually contained
food, suggesting a learned response.
Behavioral Responses Are Conditioned
• Twitmyer made a similar observation of the
knee-jerk reflex in humans: when paired with
a bell, subjects can be conditioned to
demonstrate the knee-jerk response without
other triggers.
Pavlov’s Experiments
• Classical (Pavlovian) conditioning: a neutral object
comes to elicit a response when it is associated with
a stimulus that already produces that response.
• A typical Pavlovian experiment involves
– Conditioning trials: neutral stimulus and unconditioned
stimulus are paired to produce a reflex (e.g., salivation).
• Neutral stimulus: anything the animal can see or hear as long as it
is not associated with the reflex being tested (e.g., a ringing bell).
• Unconditioned stimulus (US): a stimulus that elicits a response,
such as a reflex, without any prior learning (e.g., food)
Pavlov’s Experiments
– Critical trials: neutral stimulus alone is tested, and
effect on the reflex is measured
Terminology of Pavlov’s Experiments
• Unconditioned response (UR): a response
that does not have to be learned, such as a
reflex
• Unconditioned stimulus (US): a stimulus that
elicits a response, such as a reflex, without any
prior learning
Terminology of Pavlov’s Experiments
• Conditioned stimulus (CS): a stimulus that
elicits a response only after learning has taken
place
• Conditioned response (CR): a response to a
conditioned stimulus; a response that has
been learned
Acquisition, Second-Order
Conditioning, Extinction, and
Spontaneous Recovery
• Pavlov was influenced by Darwin and believed
that conditioning is the basis of adaptive
behaviors.
• Acquisition: the gradual formation of an
association between the conditioned and
unconditioned stimuli
– The critical element in the acquisition of a learned
association is time, or contiguity.
Acquisition, Second-Order
Conditioning, Extinction, and
Spontaneous Recovery
• The CR is stronger when there is a very brief
delay between the CS and the US.
– Scary music begins to play right before a
frightening scene in a movie—not during or after.
Acquisition, Second-Order
Conditioning, Extinction, and
Spontaneous Recovery
• Animals must learn when associations are no
longer adaptive.
– Extinction: a process in which the conditioned
response is weakened when the conditioned
stimulus is repeated without the unconditioned
stimulus
Acquisition, Second-Order
Conditioning, Extinction, and
Spontaneous Recovery
• Spontaneous recovery: a process in which a
previously extinguished conditioned response
reemerges after the presentation of the
conditioned stimulus
– The recovery will fade unless the CS is again paired
with the US.
Acquisition, Second-Order
Conditioning, Extinction, and
Spontaneous Recovery
• Extinction inhibits the associative bond, but
does not eliminate it.
• Second-order conditioning: a CS becomes
associated with other stimuli associated with
the US. This phenomenon helps account for
the complexity of learned associations.
Generalization and Discrimination
• Stimulus generalization: learning that occurs
when stimuli that are similar, but not identical,
to the conditioned stimulus produce the
conditioned response
• Stimulus discrimination: a differentiation
between two similar stimuli when only one of
them is consistently associated with the
unconditioned stimulus
Classical Conditioning
Involves More Than Events
Occurring at the Same Time
• Pavlov’s original explanation for classical
conditioning was that any two events
presented in contiguity would produce a
learned association.
– Pavlov and his followers believed that the
association’s strength was determined by factors
such as the intensity of the conditioned and
unconditioned stimuli.
Classical Conditioning
Involves More Than Events
Occurring at the Same Time
• However, in the mid-1960s, a number of
challenges to Pavlov’s theory suggested that
some conditioned stimuli were more likely
than others to produce learning.
– Contiguity was not sufficient to create CS-US
associations.
Evolutionary Significance
• Psychologist Garcia and colleagues showed
that certain pairings of stimuli are more likely
to become associated than others.
• Conditioned taste aversion: the association
between eating a food and getting sick
– Response occurs even if the illness was caused by
a virus or some other condition
– Especially likely to occur if the food was not part
of the person’s usual diet. A food aversion can be
formed in one trial.
Evolutionary Significance
– Animals that associate a certain flavor with illness,
and therefore avoid that flavor, are more likely to
survive and pass along their genes.
– Learned adaptive responses may reflect the
survival value that different auditory and visual
stimuli have based on potential dangers
associated with the stimuli.
Evolutionary Significance
• Biological preparedness: Psychologist
Seligman argued that animals are genetically
programmed to fear specific objects.
– People are predisposed to wariness of outgroup
members.
Learning Involves Expectancies
and Prediction
• Classical conditioning is a way that animals
come to predict the occurrence of events that
prompted psychologists to try to understand
the mental processes that underlie
conditioning.
– Robert Rescorla argued that for learning to take
place, the conditioned stimulus must accurately
predict the unconditioned stimulus.
Learning Involves Expectancies
and Prediction
• Rescorla-Wagner model: a cognitive model of
classical conditioning; it holds that the
strength of the CS-US association is
determined by the extent to which the
unconditioned stimulus is unexpected.
Learning Involves Expectancies
and Prediction
• Other aspects of classical conditioning
consistent with the Rescorla-Wagner model
– Prediction error: the difference between the
expected and actual outcomes
• A positive prediction error strengthens the association
between the CS and the US.
• A negative prediction error weakens the CS-US
relationship.
Learning Involves Expectancies
and Prediction
– Blocking effect: once a conditioned stimulus is
learned, it can prevent the acquisition of a new
conditioned stimulus.
• Blocking is similar to second-order conditioning, but it
involves a different process.
Dopamine and Predication Error
• Dopamine and Predication Error
– What biological mechanisms are in effect during such
learning?
– Researcher examined how dopamine neurons respond
during conditioning
– Prediction error signals alert us to important events in the
environment.
– Recent support for the error prediction model using
optogenetics
• By using optogenetics to activate dopamine neurons, researchers
actually overcame the blocking effect.
Phobias and Addictions Have
Learned Components
• Classical conditioning helps explain many
behavioral phenomena.
– Among the examples are phobias and addictions.
Phobias and Their Treatment
• Phobia: an acquired fear out of proportion to
the real threat of an object or of a situation
– Fear conditioning: the process of classically
conditioning animals to fear neutral objects
– The responses include specific physiological and
behavioral reactions.
– Freezing: may be a hardwired response to fear
that helps animals deal with predators
Phobias and Their Treatment
• In 1919, J. B. Watson became one of the first
researchers to demonstrate the role of classical
conditioning in the development of phobias by
devising the “Little Albert” experiment.
– At the time, the prominent theory of phobias was based
on Freudian ideas about unconscious repressed sexual
desires.
– Watson proposed that phobias could be explained by
simple learning principles, such as classical conditioning.
Phobias and Their Treatment
• The “Little Albert” Research Method
– Little Albert (11 months old) was presented with
neutral objects (a white rat, rabbit, dog, and
costume masks) that provoked a neutral response.
– During conditioning trials, when Albert reached
for the white rat (CS), a loud clanging sound (US)
scared him (UR).
Phobias and Their Treatment
– Results: eventually, the pairing of the rat (CS) and
the clanging sound (US) led to the rat’s producing
fear (CR) on its own. The fear response
generalized to other stimuli presented with the rat
initially, such as the costume masks.
– Conclusion: classical conditioning can cause
people to fear neutral objects.
Phobias and Their Treatment
• Watson planned to conduct extinction trials to
remove the learned phobias but Albert’s mother
removed the child from the study.
– Is this type of research ethical?
• Watson’s colleague, Mary Cover Jones, used classic
conditioning techniques to develop effective
behavioral therapies to treat phobias in 3-year-old
Peter.
– Counterconditioning: exposing a patient to small doses of
the feared stimulus while he or she engages in an
enjoyable task
Drug Addiction
• Classical conditioning also plays an important role in
drug addiction.
– Environmental cues associated with drug use can induce
conditioned cravings.
– Unsatisfied cravings may result in withdrawal, an
unpleasant state of tension and anxiety, coupled with
changes in heart rate and blood pressure.
– The sight of drug cues leads to activation of the prefrontal
cortex and various regions of the limbic system and
produces an expectation that the drug high will follow.
Drug Addiction
• Psychologist Siegel believed exposing addicts
to drug cues was an important part of treating
addiction.
– Exposure helps extinguish responses to the cues
and prevents them from triggering cravings.
Drug Addiction
• Siegel and his colleagues conducted research
into the relationship between drug tolerance
and situation.
– The body has learned to expect the drug in that
location and compensates by altering
neurochemistry or physiology to metabolize it.
– Conversely, if addicts take their usual large doses
in novel settings, they are more likely to overdose
because their bodies will not respond sufficiently
to compensate.
6.3 How Does Operant Conditioning
Change Behavior?
Learning Objectives
• Define operant conditioning.
• Distinguish between positive reinforcement,
negative reinforcement, positive punishment,
and negative punishment.
• Distinguish between schedules of
reinforcement.
• Identify biological and cognitive factors that
influence operant conditioning.
6.3 How Does Operant Conditioning
Change Behavior?
• Operant Conditioning (Instrumental
Conditioning): a learning process in which the
consequences of an action determine the
likelihood that it will be performed in the
future
– B. F. Skinner chose the term operant to express
the idea that animals operate on their
environments to produce effects.
6.3 How Does Operant Conditioning
Change Behavior?
• Edward Thorndike performed the first
reported carefully controlled experiments in
comparative animal psychology using a puzzle
box.
– Law of Effect: any behavior that leads to a
“satisfying state of affairs” is likely to occur again,
and any behavior that leads to an “annoying state
of affairs” is less likely to occur again.
Reinforcement Increases Behavior
• Thirty years after Thorndike, Skinner
developed a more formal learning theory
based on the law of effect.
– He objected to the subjective aspects of
Thorndike’s law of effect: states of “satisfaction”
are not observable empirically.
Reinforcement Increases Behavior
• Skinner believed that behavior occurs because
it has been reinforced.
– Reinforcer: a stimulus that follows a response and
increases the likelihood that the response will be
repeated.
The Skinner Box
• An operant chamber that allowed repeated
conditioning trials without requiring
interaction from the experimenter
– Contained one lever connected to a food supply
and another connected to a water supply
Shaping
• Sometimes animals take a long time to
perform the precise desired action. What can
be done to make them act more quickly?
– Shaping: an operant-conditioning technique that
consists of reinforcing behaviors that are
increasingly similar to the desired behavior
– Successive approximations: any behavior that
even slightly resembles the desired behavior
Reinforcers Can Be Conditioned
• Primary reinforcers: satisfy biological needs
such as food or water
• Secondary reinforcers: events or objects
established through classical conditioning that
serve as reinforcers but do not satisfy
biological needs (e.g., money or compliments)
What to Believe? Using Psychological
Reasoning
• Seeing Relationships That Do Not Exist: How Do
Superstitions Start?
– The list of people’s superstitions is virtually endless.
– Culture influences specific superstitions.
• In North America and Europe, the number 13
• In China, Japan, Korea, and Hawaii, the number 4
– Many sports stars, including Michael Jordan and Wade
Boggs, engage in superstitious behaviors.
What to Believe? Using Psychological
Reasoning
• The Scientific Study of Superstition
– B.F. Skinner started the scientific study of
superstitious behavior in 1948, using pigeons as
subjects.
– The pigeons developed a number of superstitious
behaviors that they normally would not perform.
– Because these pigeons were performing particular
actions when the reinforcers were given, their
actions were accidentally reinforced. This type of
learning is called autoshaping.
What to Believe? Using Psychological
Reasoning
• Associating Events that Occur Together in
Time
– Both animals and humans have a tendency to
associate events that occur together in time. This
tendency is incredibly strong because the brain is
compelled to figure things out.
– Pigeons develop behaviors that look like
superstitions and people look for reasons to
explain outcomes; the observed association serves
that purpose.
What to Believe? Using Psychological
Reasoning
• Associating Events That Occur Together in
Time
– Critical thinking requires us to understand
psychological reasoning and be aware of the
tendency to associate events with other events
that occur at the same time.
Reinforcer Potency
• Premack theorized about how a reinforcer’s
value could be determined.
– The key is the amount of time an organism, when
free to do anything, engages in a specific behavior
associated with the reinforcer.
• Premack principle: using a more valued
activity can reinforce the performance of a
less valued activity.
Positive and Negative Reinforcement
• Reinforcement—positive or negative—
increases the likelihood of a behavior.
– Positive reinforcement: the administration of a
stimulus to increase the probability of a behavior’s
being repeated
– Negative reinforcement: the removal of a
stimulus to increase the probability of a behavior’s
being repeated
Operant Conditioning Is Influenced by
Schedules of Reinforcement
• How often should reinforcers be given?
– Continuous reinforcement: a type of learning in
which behavior is reinforced each time it occurs
– Partial reinforcement: a type of learning in which
behavior is reinforced intermittently
– Partial reinforcement’s effect on conditioning
depends on the reinforcement schedule.
Operant Conditioning Is Influenced by
Schedules of Reinforcement
• Partial reinforcement can be administered according
to either the number of behavioral responses or the
passage of time.
– Ratio schedule: Reinforcement is based on the number of
times the behavior occurs.
– Interval schedule: Reinforcement is provided after a
specific unit of time.
• Ratio reinforcement generally leads to greater
responding than does interval reinforcement.
Operant Conditioning Is Influenced by
Schedules of Reinforcement
• Partial reinforcement can also be given on a
fixed schedule or a variable schedule.
– Fixed schedule: Reinforcement is provided after a
specific number of occurrences or after a specific
amount of time.
– Variable schedule: Reinforcement is provided at
different rates or at different times.
Schedules of Reinforcement
• Fixed Interval schedule (FI): occurs when
reinforcement is provided after a certain
amount of time has passed
• Variable Interval schedule (VI): occurs when
reinforcement is provided after the passage of
time, but the time is not regular
Schedules of Reinforcement
• Fixed Ratio schedule (FR): occurs when
reinforcement is provided after a certain
number of responses have been made
• Variable Ratio schedule (VR): occurs when
reinforcement is provided after an
unpredictable number of responses
Schedules of Reinforcement
• Continuous reinforcement is highly effective
for teaching a behavior. If the reinforcement is
stopped, however, the behavior extinguishes
quickly.
– Partial-reinforcement extinction effect: the
greater persistence of behavior under partial
reinforcement than under continuous
reinforcement
• This explains why gambling is so addictive.
Positive and Negative Punishment
• Punishment reduces the probability that a
behavior will recur
– Positive punishment: the administration of a
stimulus to decrease the probability of a
behavior’s recurring
– Negative punishment: the removal of a stimulus
to decrease the probability of a behavior’s
recurring
Effectiveness of Parental Punishment
• For punishment to be effective, it must be
reasonable, unpleasant, and applied
immediately so that the relationship between
the unwanted behavior and the punishment is
clear.
– Punishment often fails to offset the reinforcing
aspects of the undesired behavior.
Effectiveness of Parental Punishment
• Research indicates that physical punishment is
often ineffective, compared with grounding
and time-outs.
– Many psychologists believe that positive
reinforcement is the most effective way of
increasing desired behaviors while encouraging
positive parent/child bonding.
Behavior Modification
• Behavior modification: the use of operantconditioning techniques to eliminate
unwanted behaviors and replace them with
desirable ones
– Token economies operate on the principle of
secondary reinforcement. Tokens are earned for
completing tasks and lost for bad behavior. Tokens
can later be traded for objects or privileges.
Biology and Cognition Influence
Operant Conditioning
• Behaviorists such as Skinner believed that all
behavior could be explained by
straightforward conditioning principles.
– However, a great deal about behavior remains
unexplained.
– Biology constrains learning, and reinforcement
does not always have to be present for learning to
take place.
Biological Constraints
• Animals have a hard time learning behaviors
that run counter to their evolutionary
adaptation.
– Breland and Breland used operant-conditioning
techniques to train animals but ran into difficulty
when the tasks were incompatible with innate
adaptive behaviors.
Biological Constraints
• Conditioning is most effective when the
association between the response and the
reinforcement is similar to the animal’s built-in
predispositions.
– Bolles argued that animals have built-in defense
reactions to threatening stimuli.
Acquisition/Performance Distinction
• Tolman’s studies involved rats running through
mazes.
– Cognitive map: a visual/spatial mental
representation of an environment
• The presence of reinforcement does not
adequately explain insight learning, but it
helps determine whether the behavior will be
subsequently repeated.
Acquisition/Performance Distinction
• Tolman argued that learning can take place
without reinforcement.
– Latent learning: takes place in the absence of
reinforcement
– Insight learning: A solution suddenly emerges
after a period either of inaction or of
contemplation.
Dopamine Activity
Underlies Reinforcement
• People often use the term reward as a
synonym for positive reinforcement.
– Skinner and other traditional behaviorists defined
reinforcement strictly in terms of whether it
increased behavior.
• The neurotransmitter dopamine is involved in
addictive behavior and plays an important role
in reinforcement.
Dopamine Activity
Underlies Reinforcement
• When hungry rats are given food, they
experience an increased dopamine release in
the nucleus accumbens, a structure that is
part of the limbic system: The greater the
hunger, the greater the dopamine release.
– More dopamine is released under deprived
conditions than under nondeprived conditions.
Dopamine Activity
Underlies Reinforcement
• In operant conditioning, dopamine release
sets the value of a reinforcer, and blocking
dopamine decreases reinforcement.
– Dopamine blockers are can also help people with
Tourette’s syndrome regulate their involuntary
body movements.
Dopamine Activity
Underlies Reinforcement
• Robinson and Berridge introduced an
important distinction between the wanting
and liking aspects of reward.
– A smoker may want a cigarette but not especially
enjoy it.
• Dopamine appears to be especially important
in wanting a reward.
6.4 How Does Watching Others
Affect Learning?
Learning Objectives
• Define observational learning.
• Generate examples of observational learning,
modeling, and vicarious learning.
• Discuss contemporary evidence regarding the
role of mirror neurons in learning.
Learning Can Occur
Through Observation and Imitation
• Observational learning: the acquisition or
modification of a behavior after exposure to
another individual performing that behavior
(aka Social Learning)
– Observational learning is a powerful adaptive tool
for humans and other animals.
Bandura’s Observational Studies
• Bandura’s studies suggest that exposing
children to violence may encourage them to
act aggressively.
Modeling (Demonstration and
Imitation)
• Modeling: the imitation of observed behavior
– Modeling is effective only if the observer is
physically capable of imitating the behavior.
– Imitation is much less common in nonhuman
animals than in humans.
– Adolescents who associate smoking with
admirable figures are more likely to begin
smoking.
Vicarious Learning (Reinforcement and
Conditioning)
• Vicarious learning: learning the consequences
of an action by watching others being
rewarded or punished for performing the
same action
– A key distinction in learning is between the
acquisition of a behavior and its performance.
– Learning a behavior does not necessarily lead to
performing that behavior.
Watching Violence in Media May
Encourage Aggression
• The extent to which media violence impacts
aggressive behavior in children is debatable.
– Some studies demonstrate desensitization to
violence after exposure to violent video games.
– However, it is difficult to draw the line between
“playful” and “aggressive” behaviors in children.
• Most research in the area of TV and
aggression shows a relationship between
exposure to violence on TV and aggressive
behavior.
Fear Can Be Learned Through
Observation
• Mineka noticed that lab-reared monkeys were
not afraid of snakes the way monkeys in the
wild are.
– Her research demonstrated that animals’ fears can
be learned through observation.
• Social forces also play a role in fear-learning in
humans.
Mirror Neurons Are Activated by
Watching Others
• Mirror neurons: neurons in the brain that are
activated when one observes another
individual engage in an action and performs a
similar action
– May serve as the basis of imitation learning, but
the firing of mirror neurons does not always lead
to imitative behavior
– Possibly the neural basis for empathy and a
possible role in humans’ ability to communicate
through language