Download Lecture Outline Learning

PSYC 100
Learning
3/11/2005
Lecture Outline
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Learning
Classical Conditioning
Operant Conditioning
Cognitive-social theory
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Learning
Q Learning refers to an enduring change in the
way an organism responds based on its
experience
ß Distinct from
• Drug effects (caffeine-induced jitters are not learning)
• Fatigue or illness
Q Three assumptions of learning theories
ß Responses are learned rather than innate
ß Learning is adaptive
ß Our experiments can uncover the laws of learning
• These laws will apply to animals and to humans
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Classical Conditioning
Q The Russian physiologist Pavlov noted that
reflexive salivation in dogs could be elicited by
stimuli associated with feeding
ß Reflex: Response that is reliably elicited by a stimulus
• Food elicits salivation
• Air puff elicits eye blink
ß Reflexive stimulus and response are unconditioned
ß Neutral stimulus is referred to as the conditioned
stimulus (CS)
ß CS is paired with the UCS over many trials
ß Eventually comes to elicit a conditioned response (CR:
resembles the UCR)
Pavlov’s Experiment
Conditioned Taste Aversion
Q If a flavor is followed by an illness
experience, animals will avoid the flavor in
the future
CS
Taste
+
CS ----->
Flavor
UCS ----------> UCR
Toxic event
Nausea
CR
Nausea
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Are These Examples of Classical
Conditioning?
Q A man listening to the radio feels a rush when
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he hears a song that was popular when he was
using cocaine...
A cat runs into the kitchen when the can opener
is turning...
A war veteran dives to the street upon hearing a
car backfire...
The smell of a steak produces salivation...
A student feels nauseated when entering a
classroom in which they earlier took a difficult
exam
Stimulus
Generalization/Discrimination
Q Generalization: If a response is conditioned to
one stimulus, the organism may also respond to
a similar stimulus, but not to a dissimilar
stimulus (discrimination)
ß Hovland study:
CS
Tone
+
UCS ----------> UCR
Shock
Pain
CS alone produced changes in GSR (associated with
anxiety)
Acquisition and Extinction
Q Acquisition of classical
conditioning:
ß Repeated pairings of CS and
UCS
Q Extinction: Refers to the
weakening of conditioning
evident when the CS is
presented repeatedly
without the UCS
ß Spontaneous recovery:
Refers to the reemergence
of a previously extinguished
CR
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Classical Conditioning Issues
Q Temporal order of
presentation of CS
and UCS is
important
ß Best conditioning:
CS precedes UCS
(forward)
ß Worst conditioning:
UCS precedes CS
(backward)
Classical Conditioning Issues
Q Interstimulus interval (ISI) between CS
and UCS is important for conditioning
• ISI’s longer than 2 sec produce poor conditioning
Q Prior conditioning history is important
ß Latent Inhibition: Repeated exposure to a
neutral stimulus alone (no UCS) makes it
more difficult to use the stimulus as a CS in
the future
• Familiar ice cream taste is less likely to produce a
CTA than a novel flavor
Q Infant Albert
Q Second-order conditioning
Q Preparedness
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Operant Conditioning
Q Law of Effect: Behavior is controlled by its
consequences
ß Thorndike experiment: Hungry cat learned to pull
a string in order to leave a box and eat food from a
bowl placed just outside the box
Q Operant conditioning and instrumental
conditioning:
ß Responses operate on the environment and are
instrumental in receiving reward
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Are These Examples of Operant
Conditioning?
Q Woman inserts coins into a coke machine,
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presses the third button and receives five cans of
soda. For the next week, she presses the third
button on every coke machine she encounters...
Drug addict injects heroin into a vein…
Rat presses a lever to obtain food…
Woman pays $42.00 for groceries…
Man turns off television that was blaring an MTV
video…
Student comes to class every day in order to take
notes…
Positive Reinforcement
Q Reinforcer: An environmental stimulus
that occurs after the response and
increases the likelihood that the response
will occur in the future
ß Positive reinforcement: Process by which
presentation of a stimulus after a response
makes the response more likely to occur in
the future
ß Negative reinforcement: Termination of an
aversive event makes a behavior more likely
to occur in the future
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Issues in Negative Reinforcement
Q Negative reinforcement involves a
situation in which a response that
terminates an aversive stimulus will
strengthen that response
ß Taking an aspirin will reduce the headache
and strengthen the behavior of aspirin-taking
(sometimes referred to as escape-learning)
ß Avoidance learning: A response prevents a
potentially aversive event from occurring
• Child cleans his room to avoid parental nagging
Punishment
Q Punishment decreases the likelihood that a
response will occur
Q Examples of punishing situations
ß Presentation of an aversive stimulus (Positive)
• Parent spanks a child for taking candy...
• Owner swats a dog who has chewed her slippers...
ß Removal of a reward (Negative)
• Teenager who stays out past curfew is not allowed to drive
the family car for 2 weeks...
• Husband who forgets anniversary sleeps on couch for a
week...
Difficulties in Punishment
Q Learner may not understand which operant
behavior is being punished
Q Learner may come to fear the teacher, rather
than learn an association between the action
and punishment (then avoids the teacher)
Q Punishment may not undo existing rewards
for a behavior
Q Using punishment when the teacher is angry
Q Punitive aggression may lead to future
aggression
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Schedules of Reinforcement
Q Continuous reinforcement: Reinforcer is
obtained for every response
ß Intermittent schedules: Reinforcer is not
obtained for every response
• Ratio Schedules
– Fixed Ratio: Every Nth response
– Variable Ratio: The average is every Nth response
• Interval Schedules:
– Fixed Interval: After the elapse of N minutes
• Variable Interval: On average, after N minutes
Operant Conditioning (cont.)
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Shaping
Superstitious behavior
Discriminative stimulus
Primary vs. secondary reinforcement
Skinner: Walden II, Beyond Freedom
and Dignity
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Expectancies and Conditioning
Q Cognitive-social theory argues that we form
expectancies about the consequences of our
behaviors
ß These expectancies determine what is rewarding
Q Locus of control: Refers to general expectancy
as to whether fate does or not determine
outcomes in life
ß Internal locus: Believe that their actions determine
their fate
ß External locus: Believe that their lives are governed
by forces outside their control
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Locus of Control Scale
Q Higher-order cond.
Q Explanatory style
explain neg events
pessimistic (depressive)
internal, stable, global
Positive illusions—illusory glow
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Observational Learning
Q Modeling, vicarious conditioning
Q Banduara
Q Characteristics of models that promote
learning:
power, similarity, nurturance
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