Psych 301 Exam

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Lecture 5 Chapter 4
Psych 301 Exam
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Learning Spanish in High School Did you use
flashcards? learning the La Calavera means
skull Let's say it took 10 trials to learn this
association When did the bulk of the learning
actually take place? In the first or last
trials? In the middle?
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Most of the associative learning occurs during
the first few trials During the last trials,
very little is added to the strength of the
association Rescorla/Wagner Model attempted
to explain the growth of association
mathematically with the equation
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Rescorla-Wagner Model
What is a model?..should be able to Explain
behavior also Predict it!
conditioning
Extinction
blocking
Simple mathematical account of how associative
strength conditioning builds up over the course
of a learning experiment ? learning curve
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During Conditioning CS/UCS
Learning Curves
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Rescorla-Wagner Model
Mathematical Equation
Vn c (Vmax Vn)
Delta (change)
V Strength of Association n trial c
constant (speed of conditioning - 0-1) Vmax
asymptote (no more trials- max strength of
association) Vn the strength of association at
the beginning of the trial
Predicts the precise associative strength in each
trial
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V Strength of Association n trial c
constant (speed of conditioning 0-1) Vmax
asymptote (no more trials- max learning) Vn the
strength of association at the beginning
of the trial
Amount of conditioning for 1st trial
Vn c(Vmax Vn)
Add
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V Strength of Association n trial C
constant (maximal performance) Vmax asymptote
(best learning if a CS with UCS is paired) Vn
the strength of association at the beginning
the trial
Can also account for extinction
Vn c(Vmax Vn)
no more pairing of UCS with CS
5 ?? V5 0.30 (0-0.76) -0.21
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First Conditioning Trial

• Trial c (Vmax - Vn) ?Vn
• 1 .5 (100 - 0) 50

Vn
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Second Conditioning Trial
Trial c (Vmax - Vn) ?Vn 2
.5 (100 - 50) 25
Vn
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Third Conditioning Trial
Trial c (Vmax - Vn) ?Vn 3
.5 (100 - 75) 12.5
Vn
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4th Conditioning Trial
Trial c (Vmax - Vn) ?Vn 4
.5 (100 87.5) 6.25
Vn
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5th Conditioning Trial
Trial c (Vmax - Vn) ?Vn 5
.5 (100 - 93.75) 3.125
Vn
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6th Conditioning Trial
Trial c (Vmax - Vn) ?Vn 6
.5 (100 - 96.88) 1.56
Vn
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1st Extinction Trial
Trial c (Vmax - Vn) ?Vn 1
.5 (0 - 99.61) -49.8
Vn
Vn
99.61 49.8 49.8
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2nd Extinction Trial
Trial c (Vmax - Vn) ?Vn 2
.5 (0 - 49.8) -24.9
Vn
Vn
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Importance of Model

• Only mathematical model of behavior
• Best Theory of Classical Conditioning
• Early trials more learning occurs

Kamin (1969)The amount of conditioning on any
trial is determined not only by the UCS (shock)
but also the expectation that the CS will
occurno surprise less learning (Kamin)expect a
shockno learning
PS this model only works when the CS precedes
the UCS It does not work so well for the backward
sequencing of stimuli
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Classical Conditioning
UCS
S ------ S
CS
UCR
Association between CS UCS
Why not this instead?
UCS
CS
UCR
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food
Test the hypothesis that the association is
between CS UCS vs CS UCR
UCS
tone
CS
UCR
Try and affect association between CS UCS then
measure conditioning Post Conditioning
Devaluation alter value of UCS after conditioning
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food
Test the hypothesis that the association is
between CS UCS vs CS UCR
UCS
noise
CS
UCR
Holland Straub (1979) 1. Noise Food
?activity (CS) (UCS) (UCR) Noise ?
activity 2. Post Cond. Devaluation Food
Rotation 3. Noise ? ??.
Activity
PCD No Activity
Significant decrease in movement!
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Pavlov CS becomes the UCS ? Stimulus
Substitution Substitution Theory
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Jenkins Moore (1973)

• Pigeons autoshaping
• (Key LT food)
• food open beak/closed eyes
• H20 closed beak/eyes open
• Key Light Food
• Key Light Water
• Just Key Light (water)
• drink key light
• Just Key Light (Food)
• eat the Key Light

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Classical Conditioning
S ------ S
types of associative learning
Association between CS UCS
Operant Conditioning (instrumental learning)
S ------ R
Direct link between CS Response
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Operant Conditioning vs Classical Conditioning
In Classical Conditioning, the dogs response has
no consequences it produces no change in the
environment.
The dog gets the food after the bell is rung
whether or not he salivates to the bell. His
behavior response doesnt matter.
In Operant Conditioning, the dog has to pull the
latch to get the food. His behavior does matter.
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Operant Conditioning
The nature of behavior is determined by
its consequences whether positive or negative
Learning occurs through reinforcements
S--------R
So, in OC the reinforcer is contingent of the
response


So, in CC the reinforcer is paired with a stimulus
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Classical Conditioning A theory that attempts
to explain how organisms develop involuntary
responses to particular stimuli in the
environment B.F.Skinner (respondent behavior?
elicited by a known stimulus?UCS)
Operant Conditioning A theory that explains how
people develop voluntary behavior B.F.Skinner
(operant behavior?not elicited by a stimulus)
 
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VH1 Behind the Science

• born Willamsburg, MA
• mental telepathy in children
• studied at Harvard (James)
• hatched chicks in bedroom
• then James basement
• - Ph. D. Colombia University
• Animal Intelligence - Cats
• - Puzzle Box
• The Law of Effect
• First experimental study
• of rewards
• 1912 Prez of APA
• Do animals posses intelligence?

Edward Lee Thorndike (1874-1949)
507 pubs Applied animal to human
education Intelligence tests
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Romanes Animal learn just like we
do. Naturalistic Observation - Anecdotal
Evidence Thorndike did not buy this!..just
coincidence
Anthropomorphizing
How long would it take an animal to discover
how to get out of a box? Would this time
decrease with exposure to task?
Large box (crate) Place hungry cat in Placed
food just outside box Cat could see out Could
get out by pulling string attached to latch
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Some of Thorndikes actual cat puzzle boxes
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• - Scramble
• Claw bite
• Stumble on string
• Latency shorter
• 2nd trial
• again scramble

Puzzle Box
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• Thorndikes Conclusions
• Behavior is highly variable
• 2. Course of learning is erratic
• 3. Gradual improvement over trials
• 4. No suggestions of sudden insight
• 5. No suggestion of any mental process
• 6. Not a rational understanding but an
  association
• with the escape with the food reward

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Thorndike
theory of connectionism Through experience
neural bonds (connections) are formed between
stimuli responses Intellect facilitated neural
bonds higher intellect forms more bonds lower
intellect forms less bonds
Genetic
Content of intellect (f) experience
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Law of Effect (1911)
The presentation of a reward strengthens the
connection between the response that precedes it
and the stimuli presented at the time
Behavior that produces satisfying
consequences will be repeated, and behavior that
produces dissatisfying consequences will not be
repeated
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VH1 Behind the Science
Burrhus Fredric Skinner (1904-1990)

• - BA in English
• Wanted to be a writer
• Masters In Psych 1930
• Ph.D 1931 Harvard
• Dept. Chair, Indiana 1945
• Harvard, 1948
• -Father of Operant Conditioning
• Radical Behaviorism

Skinner strongly championed Thorndikes Law of
Effect Invented a number of devices for studying
OC (operating on the environment) Skinner Box,
Teaching Machine
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Radical Behavorism Not a science but a
philosophy Did not rule out mentation, introspec
tion, self-knowledge things that take place in
the private world of the skin
are observablebut cannot infer causes of behavior
The organism becomes a person i.e., a unique
individual as it acquires a repertoire of
behavior under the contingencies of reinforcement
to which it is exposed in its lifetime. The
behavior it exhibits at any moment is under the
control of a current setting. It is able to
acquire such a repertoire because of processes of
conditioning, to which it is susceptible because
of its genetic endowment. (Skinner, 1974)