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Classical Conditioning
Strength of Conditioning
Lecture 4Chapter 3 - Principles & Applications
British Associationists
3 Laws of Association
1. Contiguity: which sequence works best?
2. Frequency: How long do we have to pair?
3. Intensity: stronger intensity?
CS/UCS Method in which to CC
1. Sequencing of CS/UCS – Types of Conditioning –Which works Best?
UCS
CS
CS
CS Trace
CS Delay
Simultaneous
Backward
TIME
Which Sequence works best?
UCS
CS
CS
CS TRACE*
CS DELAY**
Simultaneous
Backward
TIME
.5 SEC
???? Got Contiguity
Instances of Simultaneous Conditioning Working:
Sensory Preconditioning:
Learning results from a procedure where 2 NS are presented together then one is paired with a UCS
Sensory Preconditioning (DOGS – shock to paw):
Why does learning work here?
Compound stimulus - simultaneously
NS NSStep #1
Step #2
Step #3
Simultaneous Conditioning: NS NS Normal CS UCS paring… UCS is more powerful stimulus = attention diverted
away from CS (distracted) during simultaneous
Overshadowing: differential conditioningto one element of a compound stimulus
when stimuli are represented simultaneously (overshadowing of CS because of the
UCS)
…adaptation…selective conditioning…
CS-UCS Interval
Interstimulus Interval (ISI): interval between the onset of CS & the onset of UCS
Trace Conditioning
On general the shorter the ISI the better the conditioning
About 500 msecNo conditioning at
2 seconds
2. Frequency of Pairing
Conditioning is best: early trials (30) then asymptote
3. Intensity: strength of association affected by vividness or intensity
of stimuli
RatsNo fear .50
Tone (CS) pairedwith Shock (UCS)
Greater intensity (mA)Tone elicited greater suppression (of lever press=freezing=fear)
CER: measure of fear – freeze – Immobility = fear
(experimenter not present – objective measure)Procedure:
• condition rat to level press • FR1
• Then FR20• Once rat continually pressed bar introduce “fear factor”
• Responding on level press reduced animal freezes
The measurement of fear in rats…
Are you afraid???…feces…urine
Conditioned Emotional Response (Estes & Skinner, 1941)
Strength of Association (get better CC)
Contiguity: pairing of 2 events – trace
& delay
Frequency early trials
Intensity
CS/UCS
1966 – Robert Rescorla (age of 26!!!)Concept of Contingency
It might not be as simple as the pairing of A CS & UCS (contiguity) that leads to
conditioning (learning) BUT
a predictable, CONTINGENT, relationship between the two stimuli
An “If” “then” relationshipIf one event
a) occurs, another eventb) Will follow
If /then predictability - CS must be a good predictor of the UCS
Seminal Paper!!! Is it just associations? Pairings of events???E1 E2
Contiguity
1966 – Robert Rescorla
Contingency: a statistic derived from 2 probabilitiesphi coefficient (non parametric test)
The probability that the UCS will occur in the presence of CS
P (US CS)
The probability that the UCS will occur in the absence of CS
P (US no CS)
p (shock l tone) = 0.10P(shock l no tone) = 0.10
p (shock l tone) = 1.00P(shock l no tone) = 0
No predictivevalue = .10-.10=0
predictivevalue 1.00-0=1.00
Seminal Paper!!! Is it just associations…. Pairings of events???E1 E2
Contingency
UCS occur when CS
UCS occurs w/o CS
1966 – Robert Rescorla
Table 2.1Outline of One of the Rescorla (1967) Conditioning
Experiments.
Group Probability that US follows CS
Probability that USoccurs by itself
1 .80 .80
2 .80 .40
3 .40 .40
4 .40 .00
Results: Groups 2 and 4 show conditioning.
Groups 1 and 3 do not show conditioning.
Conclusion: The CS must predict something.
Strength of Conditioning
Frequency
Intensity
CS/UCS
Contingency: CS must be
a reliable predictor
Contiguity
“Any natural phenomenon chosen at will may be converted into a conditioned stimulus…any visual stimulus, any desired sound, any odor, and stimulation of any part of the skin” (Pavlov, 1928)
Can anything be turned into a CS?
“Equipotentiality Hypothesis”
Preparedness: The tendency to associate some CS-UCS combinations more readily
then others (selective association)
Garcia & Koellings (1966) Conditioned Taste-Aversion Learning
Development of a severe negative reaction to a food item due to pairing the food
with illness or other aversive stimulation
Garcia & Koellings (1966)2nd Seminal Paper
Garcia & Koellings (1966)
Rats have “Bait Shyness”: one trial learning…
One taste of poison & will not eat again
However will go back to the place where the poison was encountered
Did the rat learn only taste-aversion?
Selectively learn?…where’s contiguity?Only associated taste & odor not visual cues?
Water with Light & Noise(bright, noisy water)
Irradiation/Xray
Electric shock
Sweetened WaterIrradiation/Xray
Electric shock
CSUCS
Garcia & Koellings (1966)
Garcia & Koellings (1966)
X-ray-ill
Shock
CS only
CS only
Findings by Garcia & KoellingExtremely important!
Demonstrated for the first time that certain CS-US combos (taste-aversion) could not be
conditioned
Preparedness!
Animals are preprogrammed or predisposed to learn certain connections
Garcia & Koellings (1966) Conditioned Taste-Aversion Learning
Argued that those connection that make sense in an organism’s natural habitat
would under go conditioning more readily
animals learned taste aversion
When X ray paired with sweet water
bright lights & tones not usuallyassociated with illness from ingestingSomething..but TASTE IS!
Garcia & Koellings (1966) Conditioned Taste-Aversion Learning
Argued that those connections that make sense in an organism’s natural habitat
would under go conditioning more readily
animals learned taste aversion
When light & tonepaired with shock
sweetened water (taste) is usuallynot associated with noise &
painful stimulation...but shock IS!
..loud noises could potentially signal
Dangerous situations like lightning,
Tree crashing down…predator…
Garcia Effect
learning doesn’t occur in the same manner with any given stimuli paired
preparedness would vary depending on the species & the environment
“Not all stimuli are created equal”
No longer use arbitrarily chosen stimuli
Shift in “paradigm”:example or model
Shift in Paradigm
Paper first published in
Psychonomics Science?
Rejected!!!!
Disbelief in results Contiguity
DID NOT FOLLOWLaws of Association
Strength of Conditioning
UCS/CS
contingency preparedness
Contiguity
Frequency
Intensity
another finding against contiguity- Blocking
Occurs when initial conditioning to a CS1
impairs later conditioning to a another CS2 Kamin (1969)
Used noise & lightpaired with shock
CR= fearRats (CER)
Pretraining Conditioning
Blocking N shock NLshock
Control NLshock
Control grp:noise alone & light caused fearBlocking grp: only noise caused fear…conditioning with noise blocked light from being associated
Mary Cover Jones“mother of Behavioral Therapy”
• Johnston, PA•Vassar College•“took every class in Psych”•Graduated in 1919 •Attended weekend lecture… J.B. Watson• Little Peter – fear of rabbits
1987-1987
Mary Cover Jones (1924)Mary Cover Jones (1924)CounterCounter--condition condition I n counterI n counter--conditioning the stimulus is conditioning the stimulus is
paired with a new response which is paired with a new response which is incompatible with the old oneincompatible with the old one
Used to treat phobiaUsed to treat phobia“Peter & the Rabbit” “Peter & the Rabbit” –– 3 year3 yearSlowly, gradually introduced the rabbit Slowly, gradually introduced the rabbit
(CR(CR--f ear) with f eeding (happy f ear) with f eeding (happy –– new CR)new CR)A few days…no f ear!A f ew days…no f ear!First Behavior TherapistFirst Behavior Therapist
1st application of Using Counter Conditioning
“Systematic Desensitization”“Systematic Desensitization”
WolpeWolpe (1958)(1958)attempted to counterattempted to counter--condition people condition people
suff ering f rom phobiassuff ering f rom phobiasI n counterI n counter--conditioning the stimulus is conditioning the stimulus is
paired with a new response which is paired with a new response which is incompatible with the old one..relaxationincompatible with the old one..relaxation
WolpeWolpe basically utilizes an anxiety basically utilizes an anxiety hierarchy to gradually but systematically hierarchy to gradually but systematically desensitize the patient over several desensitize the patient over several therapy sessionstherapy sessions
Systematic Desensitization of a Systematic Desensitization of a Spider PhobiaSpider Phobia
Show a picture of a spider to the patientShow a picture of a spider to the patient HR goes up HR goes up –– but talk to them but talk to them –– get them to relax get them to relax ––
eventually they are okayeventually they are okay Toy spider that looks fakeToy spider that looks fake
HR goes up HR goes up –– but talk to them but talk to them –– get them to relax get them to relax ––eventually they are okayeventually they are okay
Toy spider that looks realToy spider that looks real HR goes up HR goes up –– but talk to them but talk to them –– get them to relax get them to relax ––
eventually they are okayeventually they are okay A real dead spiderA real dead spider
HR goes up HR goes up –– but talk to them but talk to them –– get them to relax get them to relax ––eventually they are okayeventually they are okay
A live spiderA live spider HR goes up HR goes up –– but talk to them but talk to them –– get them to relax get them to relax ––
eventually they are okayeventually they are okay
Criticism of Systematic Criticism of Systematic DesensitizationDesensitization
Wolpe’sWolpe’s critics say there is no attempt to achieve critics say there is no attempt to achieve insight into the underlying cause of the fearinsight into the underlying cause of the fear
WolpeWolpe says “so what”says “so what” He’s not really concerned about what caused it as He’s not really concerned about what caused it as
long as its alleviatedlong as its alleviated
Only concern is that the maladaptive behavior is Only concern is that the maladaptive behavior is cured and that patients feel better about themselves cured and that patients feel better about themselves and begin acting in ways that will bring them greater and begin acting in ways that will bring them greater life satisfactionlife satisfaction
Behavioral Therapy vs Psychotherapy
environment mind
psychotherapy
behavior
behavioral therapy
Behavioral Therapy vs Psychotherapy
environment mind
Change environment
behavior
behavioral therapy
Behavioral Therapy vs Psychotherapy
environment mind behavior
Psychotherapist
What works best?
Ex: Enuresis
Psychotherapy:-Underlying Psychological issue why
child wets the bedlong term therapy
$$$$$$$$
Behavioral Therapy:Train child to associate bladder function
with awakening…Minimal cost for pad
Few trials
