Transcript Chapter 06: Learning PowerPoint

Chapter 6:
Learning
Slides prepared by
Randall E. Osborne, Texas State University-San Marcos,
adapted by Dr Mark Forshaw, Staffordshire University, UK
1
Defining Learning:
Experience That Causes a
Permanent Change
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Defining Learning
• Learning – Experience that causes a
permanent change
• Habituation
– gradual reduction in responding
3
Learning and Behaviourism
• Behaviourism: 1930s – 1950s
• Observable, quantifiable behaviour
• Mental activity is irrelevant and
unknowable
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Classical Conditioning:
One Thing Leads to
Another
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Classical Conditioning
– Unconditioned stimulus (US)
– Unconditioned response (UR)
– Conditioned stimulus (CS)
– Conditioned response (CR)
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Classical Conditioning
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Classical Conditioning
• Basic principles of classical
conditioning
–
–
–
–
–
Acquisition
Extinction
Spontaneous recovery
Generalization
Discrimination
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Classical Conditioning: Acquisition
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Classical Conditioning:
Generalization
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Conditioned Emotional Responses
“Even complex behaviors are the result of
conditioning.” John Watson
• 9-month-old “Little Albert”
• Stimuli—white rat; dog; rabbit; burning
newspaper:
– Showed curiosity
– Then shown stimulus (rat) and loud noise when he
reached to touch it—result was fear
– Soon sight of rat caused fear
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Conditioned Emotional Responses
• Watson’s goals:
– Complex reactions can be conditioned using Pavlovian
techniques
– Emotional responses (such as fear) are learned and not
result of unconscious processes
“Give me a dozen healthy infants, well-formed, and my own
specified world to bring them up in and I’ll guarantee to take any
one at random and train him to become any type of specialist I
might select – doctor, lawyer, artist, merchant-chief and, yes,
even beggar-man and thief, regardless of his talents,
penchants, tendencies, abilities, vocations, and race of his
ancestors.”
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A Deeper Understanding of
Classical Conditioning
• Neural elements
– Amygdala—central nucleus
• Cognitive elements
– expectation
• Evolutionary elements
– survival (such as food aversions)
– adaptiveness
– biological preparedness
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Seligman and the Sauce Béarnaise
• Seligman’s favourite sauce
• He became very ill after eating steak with
sauce Béarnaise
• No direct link between the sauce and the
illness, but it put him off the sauce entirely
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Operant Conditioning:
Reinforcements from
the Environment
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Operant Conditioning
• E. L. Thorndike
(1874-1949)
• Instrumental
behaviours
• Puzzle box
• Law of effect
• Watson originally
rejects need for
reward
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Operant Conditioning
•
•
•
•
B. F. Skinner
Operant conditioning
Operant chamber
Reinforcer
– Positive
– Negative
• Punishment
– Positive
– Negative
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Operant Conditioning
• Primary reinforcement
• Secondary reinforcement
• Primary punishment
• Secondary punishment
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Operant Conditioning
• Which reinforcers are more effective?
• Premack principle
– “no TV until the homework is done”
• Relatively reinforcing
– Water to reinforce a thirsty rat for exercising
– Non-thirsty rat drinking in order to exercise
• Overjustification effect
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Basic Principles of Operant
Conditioning
• Discrimination
• Generalisation
• Importance of context
• Extinction
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Operant Conditioning
• Schedules of
reinforcement
– fixed-interval
(set time)
– variableinterval
(average time)
– fixed ratio (set
number)
– variable ratio
(average
number)
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Operant Conditioning
• Ratio schedules
– high rates of responding because number of
rewards received is directly related to the
number of responses made
• Intermittent-reinforcement effect
– resist extinction
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Operant Conditioning
• Superstitious behaviour
– Skinner’s superstitious pigeons
– reinforcement of accidental behaviour
– ‘stench causes goals’ hypothesis formed
when footballers score on days they didn’t
shower
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Operant Conditioning—Neural
Elements
• Pleasure centres
– nucleus
accumbens
– medial forebrain
– hypothalamus
– involve dopamine
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Operant Conditioning—Cognitive
Elements
• Edward Tolman
(1886-1959)
• Means-ends
relationships
• Latent learning
• Cognitive map
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Operant Conditioning—
Evolutionary Elements
• Rats trained to let in T-maze to get food
• Next day turned right (contrary to
conditioning)
• Why?
– rats are foragers
– adaptive foraging strategy is to NOT search for
food the same place twice
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Observational
Learning: Look at Me
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Observational Learning
• Learning without direct experience
– Observational learning
• Adult models guide child learning
• Learning by observation occurs in animals
– Monkeys learning to fear snakes by watching
other monkeys react to snakes
• Mirror neurons: fire when you perform an
action, but also fire when you see someone
else perform an action
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Implicit Learning:
Under the Wires
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Implicit Learning
• Implicit learning
• Ways to study
implicit learning
– artificial grammar
– can learn “rules”
even without being
taught rules
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Implicit Learning
• Characteristics of implicit learning
– smaller individual differences than explicit
– unrelated to IQ
– changes little across lifespan
– resistant to disorders that impair explicit
- strongly suggests that explicit and implicit learning
use different neural pathways
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