Transcript Classical Conditioning: Underlying Processes and Practical Applications Chapter 5 Dr. Steven I. Dworkin

Classical Conditioning: Underlying
Processes and Practical Applications
Chapter 5
Dr. Steven I. Dworkin
Underlying Processes
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S-S versus S-R learning
Stimulus Substitution versus Preparatory-Response Theory
Compensatory-Response Model
Rescorla-Wagner Theory
Dr. Steven I. Dworkin
S-S versus S-R Learning
• S-R
– Neutral stimulus becomes associated with
unconditioned response.
• S-S
– Neutral stimulus becomes directly associated with the
unconditioned stimulus.
Dr. Steven I. Dworkin
Stimulus-Substitution versus
Preparatory Response Theory
• Stimulus-Substitution
– CS acts as substitute for US
• Preparatory-Response Theory
– The CR prepares the organism for presentation of US
• Compensatory-Response Theory
– The CR counteracts the effects of the UR
Dr. Steven I. Dworkin
Rescorla-Wagner Model of Conditioning
• For every presentation of CS
– Excitatory conditioning
– Inhibitory conditioning
– No conditioning
Dr. Steven I. Dworkin
Rescorla-Wagner Model of Conditioning
• Behavioral theory of conditioning does not make
inferences about expectations or other underlying cognitive
functions
• CS acquires a limited amount of associative strength on
each trial.
– Associative strength – magnitude of elicited CR
– Maximum associative strength – Asymptote of
maximum CR <=UR
Dr. Steven I. Dworkin
Rescorla-Wagner Model of Conditioning
• CS gains certain amount of associative strength on any one
trial.
• Change is associative strength – difference between
present strength of CS and maximum possible value.
• This difference diminishes with each pairing as associative
strength is increased.
• The sum of the associative strength of all CSs <=UR
Dr. Steven I. Dworkin
Acquisition
VMAX
Associative Strength
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Si=0.25
VMAX=10.00
VSUM= 0.00
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Trials
Dr. Steven I. Dworkin
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Conditioning Effects and the RescorlaWagner Equation
rVi = Si(VMAX–Vi-VSUM)
 rVi – amount of change in associative strength for any CS on any
one trial.
– Si – constant varies between 0.00 and 1.00 measure of salience of
CS and sensory capacity of organism. Estimated after
conditioning. How quickly associative strength raises to maximum.
– VMAX – maximum associative strength – magnitude of UR
– Vi – associative strength already accrued to CS1
– VSUM – associative strength already accrued to CS2…CSn
Dr. Steven I. Dworkin
Rescorla-Wagner Equation
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Trial
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T Assoc Strength
.0000
2.5000
4.3750
5.7800
6.8550
7.6400
8.2300
8.6700
9.0000
9.2500
9.4400
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rVi = Si(VMAX–Vi-VSUM)
Si=0.25
Vmax=10
Vsum=0
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i=1rVi =.25(10)=2.5
i=2rVi =.25(10-2.5)=1.88
i=3rVi =.25(10-4.375)=1.4
i=4rVi =.25(10-5.78)=1.05
i=5rVi =.25(10-6.85)=.78
Dr. Steven I. Dworkin
Acquisition
VMAX
Associative Strength
10
8
Si=0.25
VMAX=10.00
VSUM= 0.00
6
4
2
0
0
2
4
6
Trials
Dr. Steven I. Dworkin
8
10
Practical Applications
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Understanding Phobias
Treating Phobias
Aversion Therapy
Medical Applications
Dr. Steven I. Dworkin
Understanding Phobias
• Overgeneralizations
• Watson and Rayner
• Additional Factors
– Observational learning
– Temperament
– Preparedness
– History of control
– Incubation –strengthening by brief exposure to CS
– US revaluation
– Selective sensitization
Dr. Steven I. Dworkin
Treating Phobias
• Systematic desensitization
– Counter conditioning
• Reciprocal inhibition
– Training in relaxation
– Creation of hierarchy
– Pairing of items in hierarchy with relaxation
Dr. Steven I. Dworkin
Treating Phobias
• Flooding – prolong exposure to feared stimulus
• Aversion Therapy
Dr. Steven I. Dworkin
Medical Applications
• Neuropsychoimmunology
• Drug Relapse Prevention
Dr. Steven I. Dworkin
Biological Preparedness
• Equipotentiality premise – all environmental stimuli that
can be detected by an organism can serve as conditioned
stimulus.
• A given stimulus will be equally good in all contexts
Dr. Steven I. Dworkin
Garcia and Koelling 1966
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CS1 - bright noisy water
CS2 – taste
US1- illness
US2- shock
Dr. Steven I. Dworkin