Transcript Group 1

Classical Conditioning – Ch. 5
September 16, 2005
Class #11
Stimulus-Substitution Theory

Pavlov’s early idea that the tone was
the substitute for food
Preparatory-Response Theory

The purpose of CR is to prepare
organism for the UCS


The dog salivates to the tone so as to get
ready for the presentation of the food
The rat freezes in response to the light so it
is ready for the painful shock
Compensatory-Response Model of
Classical Conditioning

The compensatory after-reactions to a
UCS may come to elicit the CS

Conflict with Pavlov’s early theory

See next slide
Pavlov’s Early Classical
Conditioning Experiments
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UCS ------------------------------------------- UCR
(shock)
(HR increase)
NS -------------------------------------------- NO RESPONSE
(tone)
NS + UCS ----------------------------------- UCR
(tone) (shock)
(HR increase)
* This is repeated several times…
CS --------------------------------------------- CR
(tone)
(HR increase)
But with further pairings…


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UCS ------------------------------------------- UCR
(shock)
(HR increase)
NS -------------------------------------------- NO RESPONSE
(tone)
NS + UCS ----------------------------------- UCR
(tone) (shock)
(HR increase)
* This is repeated several times…
CS --------------------------------------------- CR
(tone)
(HR increase)
NS + UCS ----------------------------------- UCR
(tone) (shock)
(HR increase)
* This is repeated several more times…
CS --------------------------------------------- CR
(tone)
(HR decrease)
What other theory does this remind you of???
Classical Conditioning:
Drug Tolerance Example

Drug Tolerance



Drugs have less of an effect when taken
repeatedly (less of a high)
Drug users crave more of the drug despite its
lessening effects
It appears that certain drugs trigger our body
to call upon its defenses against the effects of
the drug
Drug Tolerance

Siegel et al. (1982)


Demonstrated that classical conditioning
principles might be in effect during druginjecting episodes…
Possible reason for overdoses???
Siegel’s theory…


UCS ---------------------------------------------- UCR
(drug)
(anti-drug defenses)
NS ----------------------------------------------- NO RESPONSE
(injection ritual)
(no defenses)
NS + UCS -------------------------------------- UCR
(injection ritual) + (drug)
(anti-drug defenses)
* Repeated several times
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
CS ----------------------------------------------- CR
(injection ritual)
(anti-drug defenses)
Siegel’s theory…

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Familiar setting----------------------- anti-drug defenses
(usual time, place, etc)
(body reacts)
New setting ---------------------------- no defenses
(place, time are different)
(body doesn't react)
The same dosage now becomes an
overdose – they get too high as their
bodies have been fooled by the new
procedure
Siegel’s Model
Initial Exposure
Sight of
needle, taste
of beer, etc.
Neutral Stimuli
Later Effects
Sight of drugassociated
stimuli
CS
Effects of
drug on
neurons
Compensatory
reaction
opposing drug
effects
UCS
UCR
Compensatory
reactions. Resemble
withdrawal effects in
the absence of the
drug.
CR
Siegel, Hinson, Krank, & McCully (1982)

In this experiment laboratory rats
were preconditioned to a tolerance of
large doses of heroin…

Procedure:
Lab rats given daily intravenous injections for 30
days
 Placebo or heroin given either in “animal colony” or
alone in “white noise” room on alternate days
 Counterbalance of treatment:
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For some rats: heroin in WN; placebo in AC
For others: heroin in AC; placebo in WN
Control group received only placebo in different rooms
on alternate days
So this then gives us 3 main
Groups:
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Group 1:
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Group 2:
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Received placebo in the Colony room (their normal living
quarters) and heroin in the Noisy room the next day
Group 3:

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Received heroin in the Colony room (their normal living
quarters) and placebo in the Noisy room the next day
Received placebo in the Colony room (their normal living
quarters) and placebo in the Noisy room the next day
All rats were then injected with a large dose of
heroin (15 mg/kg)
But does it depend on the room???

But the room in which this potentially lethal dose of heroin was
administered was varied between subgroups of rats…
 Group 1A were injected with heroin in the Colony room where they had received all their previous injections of heroin
 Group 1B were injected with heroin in the Noisy room - where
they had never received any previous injections of heroin
 Group 2A were injected with heroin in the Noisy room - where
they had received all their previous injections of heroin
 Group 2B were injected with heroin in the Colony room where they had never received any previous injections of
heroin
 Group 3A were injected with heroin in the Colony room - they
had no previous injections of heroin
 Group 3B were injected with heroin in the Noisy room - they
had no previous injections of heroin
Results: Death Rate
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Group 3 showed
substantial mortality
(96%)
A group with prior
exposure in the same
cage showed tolerance
(only 32% died)
A group with the same
history of exposure, but
tested in an environment
not previously associated
with heroin showed
higher mortality (64%)
Results: Death Rate

Results:

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50% increase in death rate in new room
Rats show "room-specific" tolerance
McCusker and Brown (1990)

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In a study analyzing alcohol's effects on the
performance of an eye-hand coordination task,
a group of men classified as social drinkers
received alcohol either in an office or in a room
resembling a bar
Most subjects performed the task better (i.e.,
were more tolerant) when drinking in the
barlike environment

Results suggest:
 This suggests that for many people, a bar contains
cues that are associated with alcohol consumption
and promote environment-dependent tolerance
 Environment-dependent tolerance develops even in
"social" drinkers in response to alcohol-associated
cues
Conditioned Taste Aversion

Doesn't fit exactly within all the rules of
classical conditioning…
 Occurs reliably after only a single trial
(one pairing)
 Timing doesn't seem to be much of a
factor – strong learning is taking place
despite delays of minutes or hours or
more
Garcia and Koelling (1966)

Rats drink flavored water from tubes that flashed
light and made noise when the tubes were
licked…

Group 1:
 Rats
were given electric shocks to their
feet two seconds after beginning to drink

Group 2:
 Rats
were exposed to X rays (which made
them sick) while they drank

Later, both groups were tested with a tube of flavored water
producing lights and noise and a tube of unflavored water
that was not producing lights and noise… so rats are
basically given a choice between these two tubes to drink
from
Garcia and Koelling (1966)

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Group 1 (rats that had been shocked) avoided the
tube producing the lights and noise while Group 2
(rats that had been made sick) avoided only the
flavored water
Conclusion:
 Evidently, rats (and other species) have a built-in
predisposition to associate illness mostly with what they
have eaten or drunk (Group 2 rats) and to associate skin
pain mostly with what they have seen or heard (Group 1
rats)
 This is another example of preparedness – organisms
are "biologically prepared" or "genetically tuned" to
develop certain conditioned associations

Note: In literature, this is sometimes referred to as
biopreparedness
Valentine (1930): Extends “Little Albert”
experiments
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Another example of preparedness…
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This researcher actually blows loud whistle
whenever his infant touched certain objects
Interesting (although ethically-troublesome)
results:
When she touched a pair of glasses there was
no response
 When she touched a caterpillar she began to cry
 Other participants also showed similar reactions
to dogs, etc.
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Websites you can check for additional
information:

Information contained on slides #12-16
taken from following website:


http://salmon.psy.plym.ac.uk/year3/DrugAbuse/d
rugtolerance.htm
Slide #11 prepared by Keith Clements and
taken from his website:

http://ibs.derby.ac.uk/~keith/b&b/tolerance.ppt