Transcript Garcia & Koellings (1966)

Lecture 4
Chapter 3 - Principles & Applications
Classical Conditioning
Strength of Conditioning
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?
TIME
UCS
CS
CS
Trace
Delay
CS
Simultaneous
CS
Backward
Which Sequence works best?
TIME
UCS
CS
.5 SEC
DELAY**
CS
CS
CS
TRACE*
???? Got Contiguity
Simultaneous
Backward
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):
Compound stimulus - simultaneously
Step #1
NS
Step #2
Step #3
Why does learning work here?
NS
Simultaneous Conditioning: NS NS
Normal CS UCS paring… UCS is more
powerful stimulus = attention diverted away
from CS (distracted) during simultaneous
Overshadowing: differential conditioning
to 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
About 500 msec
No conditioning at
2 seconds
On general the shorter the ISI the better the conditioning
2. Frequency of Pairing
Conditioning is best: early trials (30) then asymptote
3. Intensity: strength of association
affected by vividness or intensity
of stimuli
Rats
No fear .50
Tone (CS) paired
with Shock (UCS)
Greater intensity (mA)
Tone elicited greater
suppression (of lever
press=freezing=fear)
The measurement of fear in rats…
Are you afraid???
…feces
…urine
Conditioned Emotional Response (Estes & Skinner, 1941)
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
Strength of Association
(get better CC)
Contiguity: pairing
of 2 events – trace
& delay
CS/UCS
Frequency
early trials
Intensity
Robert Rescorla
1940 —
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” relationship
If one event
a) occurs, another event
b) Will follow
If /then predictability - CS must be a good predictor
of the UCS
1966 – Robert Rescorla
Seminal Paper!!!
Is it just
associations?
Pairings of
events???
E1
E2
Contiguity
Contingency: a statistic derived from 2 probabilities
phi 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) = 0.10
P(shock l no tone) = 0.10
p (shock l tone) = 1.00
P(shock l no tone) = 0
No predictive
value = .10-.10=0
predictive
value 1.00-0=1.00
1966 – Robert Rescorla
Seminal Paper!!!
Is it just
associations….
Pairings of
events???
E1
E2
Contingency
UCS occur when
CS
UCS occurs w/o
CS
Table 2.1
Outline of One of the Rescorla (1967) Conditioning Experiments.
Group
Probability that US
follows CS
Probability that US
occurs 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
Contiguity
CS/UCS
Frequency
Intensity
Contingency: CS must be
a reliable predictor
Can anything be turned into a CS?
“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)
“Equipotentiality Hypothesis”
Garcia & Koellings (1966)
2nd Seminal Paper
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)
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?
CS
Water with Light & Noise
(bright, noisy water)
Sweetened Water
UCS
Irradiation/Xray
Electric shock
Irradiation/Xray
Electric shock
Garcia & Koellings (1966)
Garcia &
Koellings
(1966)
CS
only
X-ray-ill
CS
only
Shock
Findings by Garcia & Koelling
Extremely 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 usually
associated with illness from ingesting
Something..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 & tone
paired with shock
sweetened water (taste) is usually
not associated with noise & painful
stimulation...but shock IS!
..loud noises could potentially signal
Dangerous situations like lightning,
Tree crashing down…predator…
Shift in Paradigm
Paper first published in
Psychonomics Science?
Rejected!!!!
Disbelief in results
DID NOT FOLLOW
Laws of Association
Contiguity
Strength of Conditioning
Contiguity
UCS/CS
Frequency
Intensity
contingency
preparedness
another finding against contiguity- Blocking
Occurs when initial conditioning to a CS1
impairs later conditioning to a another CS2
Kamin (1969)
Used noise & light
paired with shock
CR= fear
Rats (CER)
Pretraining
Blocking
Control
N shock
Conditioning
NLshock
NLshock
Control grp:noise alone & light caused fear
Blocking 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
1st application of Using Counter Conditioning
Behavioral Therapy vs Psychotherapy
behavioral therapy
environment
mind
psychotherapy
behavior
Behavioral Therapy vs Psychotherapy
behavioral therapy
environment
Change environment
mind
behavior
Behavioral Therapy vs Psychotherapy
environment
mind
Psychotherapist
behavior
What works best?
Ex: Enuresis
Psychotherapy:
-Underlying Psychological issue why
child wets the bed
long term therapy
 $$$$$$$$
Behavioral Therapy:
Train child to associate bladder function
with awakening…
Minimal cost for pad
Few trials