Transcript Learning PPT

Learning Theories
Goal  How do we learn behaviors through
classical conditioning?
Learning is…
• Relatively permanent
• Change in behavior
• Due to experience
Behaviorism  Psychology
should focus on observable
behavior
Associative Learning
Classical Conditioning:
associate two stimuli
together to anticipate events
Operant Conditioning:
associate a behavior with a
good or bad result
Ivan Pavlov’s Experiment
• Founded classical conditioning
• Measured salivation of dogs to food
– Dogs began to salivate to the sight
of the researchers, not just the
food…
Pavlov’s Experiment
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UR
UC
CR
CS
Classical Conditioning
• Acquisition = pairing
of CS and US, learning
of the association
• Extinction = CS no
longer paired with UCS,
CR stops
• Extinction
Classical Conditioning
Strength
of CR
Acquisition
(CS+UCS)
Spontaneous
Recovery = sudden
Spontaneous
recovery
of
reappearance
of CR
CR
after extinction
Extinction
(CS alone)
Extinction
(CS alone)
Pause
John B. Watson & “Little Albert”
http://www.youtube.com/watch?v=KxKfpKQzow8&feature=related
• Generalization
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• Discrimination
Taste Aversion
UC
UR
CS
CR
Factors Influencing Classical Conditioning
Conditioning is stronger if…
• CS consistently predicts UCS
• CS/UCS are paired frequently
(more trials)
• UCS is intense (causes strong
response)
• CS is presented immediately
before UCS
• We better learn associations when…
– It is useful for survival
• Biological predispositions, adaptive
– It does not involve cognitive processing
• i.e. alcohol & nauseating drug
CS
UCS
Learned Response
Loud Noise
Shock
Fear
Loud Noise
Radiation (nausea)
Nothing
Sweet Water
Shock
Nothing
Sweet Water
Radiation (nausea)
Avoid Water
Garcia & Koelling’s study on biological
predispositions to classical conditioning
Biopsychosocial Influences on Learning
Biological
• Genetic predispositions
• Unconditioned responses
• Adaptive responses
Psychological
• Previous experiences
• Predictability of associations
• Generalization
• Discrimination
LEARNING
Social-Cultural
• Culturally learned preferences
• Motivation, affected by
presence of others
Learning Theories
Goal  How do we acquire behaviors
through operant conditioning?
Edward Thorndike’s Law of Effect
• Cats placed in “puzzle
boxes”
• Use trial-and-error to
“escape”
• Continue behaviors w/good
result
• Discontinue behaviors
w/bad result
B.F. Skinner
“Skinner Boxes”
Operant Conditioning
• Reinforcement
– Make a behavior more likely to be performed again
• Punishment
– Make a behavior less likely to be performed again
Reinforcement
Positive Reinforcement
• Increases response by
presenting positive
stimulus
Negative Reinforcement
• Increases response by
removing negative
stimulus
Punishment
Positive Punishment
Negative Punishment
• Decrease behavior by
presenting bad stimulus
• Decrease behavior by
removing good stimulus
(omission training)
Punishment is not as effective as
Reinforcement because it…
• Suppresses behavior
(not forgotten)
• Teaches discrimination
• Teaches fear
• May increase
aggressiveness
Reinforcers
Primary Reinforcer
• Unlearned
Conditioned (Secondary)
Reinforcer
• Learned through association
Immediate v. Delayed Reinforcers
Continuous v. Partial (Intermittent) Reinforcement
Shaping
• Reinforce each step (successive
approximation) toward desired behavior
Schedules of Partial Reinforcement
• Fixed-ratio – reinforcement after a set or
fixed number of behaviors occur
• Variable-ratio – reinforcement after different
numbers of behaviors
# Behaviors
Fixed-ratio
Variable-ratio
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Schedules of Partial Reinforcement
• Fixed-interval – reinforcement after a set or
fixed amount of time
• Variable-interval – reinforcement after
different amounts of time
Time (hrs.)
Fixedinterval
Variableinterval
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Extending Operant Conditioning
Cognitive Influences
• Cognitive map – mental representation of
environment
• Latent Learning – learning not known until there
is motivation to demonstrate it
Biology & Operant Conditioning
• Biological constraints predispose organisms to
learn associations that are naturally adaptive
– Pigeons naturally peck
• Easy to teach pigeons to peck to
receive food
– Pigeons naturally flap wings
• Teach pigeons to flap wings to
avoid shock
– However, difficult to teach
pigeon to flap wings to get
food, or peck to avoid shock
Applications of Operant Conditioning
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School – token economy
Sports
Work – schedules of reinforcement
Home
Self-improvement - Biofeedback
Operant vs Classical Conditioning
Observational Learning
• “social learning”
• We observe & imitate others’ behavior
• Modeling: demonstrating behavior to be
learned
Mirror Neurons
• Frontal lobe
• Fire when performing
certain actions OR when
seeing someone else
perform those actions
• Role in emotions,
empathy (theory of mind)
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http://video.pbs.org/video/1615173073/
Bandura’s “Bobo Doll” Study
• http://www.psychologicalscience.org/index.php/publica
tions/observer/obsonline/bandura-and-bobo.html
Vicarious Conditioning
• Part observational learning
• We learn by observing others’ reactions to
stimulus or others’ outcomes
– Learn to be afraid of shots at the doctor after
watching your sister cry after getting a shot
– Seeing a friend get a sticker for an A on his
homework (you learn to do your homework)
Prosocial Effects
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Role models
Model reading, helpful behaviors, nonviolence
Consistency is key – BUT….
“Do as I say, not as I do” = children imitate the
hypocrisy!
Antisocial Effects
• Aggression  violence-viewing effect?
• Desensitization to violence
• Promiscuity? Drug use?