Transcript 3 - smw15.org

PSY 445: Learning & Memory
Chapter 3:
Classical Conditioning
Pavlovian Conditioning

Pavlov was a research
physiologist, not a
psychologist
 At age 33, earns MD
 Spends next 20 years
studying the digestive system
 Russia’s first Nobel Prize
winner in 1904

Novel work done over the
final 30 years of his life that
earns him his place in
scientific history
Ivan Pavlov
(1849-1936)
Definition of Classical Conditioning



In classical conditioning, the organism learns a
connection between two stimuli
 In other words, the organism learns that one stimulus
predicts another stimulus
A form of associative learning
 Learning in which connections are formed between
internal representations of events (e.g., stimuli and
responses) during learning.
Procedure
 Classical conditioning is the presentation of two or
more events in an experimentally determined
temporal relationship
 Any change in responding to one of the events is
seen as evidence of a learned association
Definition of Classical Conditioning

Unconditioned stimulus (US)
 In classical conditioning, this is the stimulus that
elicits the unconditioned response (UR) without
conditioning

Conditioned stimulus (CS)
 In classical conditioning, this is the stimulus which
comes to elicit a new response by virtue of pairings
with the unconditioned stimulus

Unconditioned response (UR)
 In classical conditioning, the automatic (involuntary),
unlearned reaction to a stimulus

Conditioned response (CR)
 A learned response elicited as a result of pairings
between that NS and an UCS
Pavlov’s Paradigm
Pavlov’s Participants 
Methods of Studying Classical Conditioning
Eyeblink Conditioning
Skin Conductance Response
Conditioned Taste Aversion
Evaluative Conditioning
Eyeblink Conditioning
The procedure is relatively simple and usually consists of pairing an
auditory or visual stimulus (CS) with an eyeblink-eliciting US
 For example, light might be paired with a mild puff of air to the cornea or
a mild shock
After many CS-US pairings, an association is formed such that a
learned blink, CR, occurs and precedes US onset
 The magnitude of learning is generally gauged by the percentage of all
paired CS-US trials that result in a CR
In this video clip, experimenter
paired puff of air with pencil tap 
Skin Conductance Response (SCR)
Electrodes put on the arm or palm
 A loud unexpected noise or mild shock (US)
will usually cause this response (OR)
 Soft tone or light may be presented before the
US
 Several pairings
 Just the tone or light (CS) will produce the SCR
(CR)

Electrodes will be put on participants prior
to presentation of CS-US pairings 
Conditioned Taste Aversion
Typical Procedure
 Rats are given novel taste (saccharin-flavored
water) is followed by an illness-producing drug
 Gastrointestinal distress
 Flavored water is again presented
Typical Results
 Decrease or complete avoidance of the flavored
water (CS)
Evaluative Conditioning
A change in liking, which occurs due to an
association with a positive or negative stimulus
 Neutral stimulus is paired with something
one likes or dislikes
 Is not reflex-evoking
After these movies came out in 1980s,
the hockey mask was never the same 
Evaluative Conditioning
Typical Procedure
 An affective neutral stimulus is presented along with
another stimulus that already evokes some type of
affective evaluation
 For example, a word (NS) is paired with an bad
odor (US)
Typical Results
 Emotional tone of the neutral stimulus will change to
correspond to the US
 The word (CS) will come to evoke a negative
feeling (CR) from the person who has gone through
this type of conditioning
Evaluative Conditioning
Hammerl, Bloch, & Silverthorne (1997)
Procedure
 Scenic pictures were pre-rated
 Pictures that were originally rated as neutral (NS) were
then paired (five trials) with either pictures that were rated
low or rated high (US)
Results
 When paired with the high-ranked pictures, the neutral
pictures received more positive ratings then before; when
paired with the low-ranking pictures they received less
positive ratings then before
 Thus, the originally neutral pictures become the CS and
the resultant ratings of these pictures become the CR
Evaluative Conditioning

Limitations
 Doesn’t fit classical conditioning pardigm completely
 Reliance just on verbal reports is questionable
 Some believe the changed preferences are based
on conscious knowledge; not automatic responses
What stimuli can serve as CSs?
Exteroceptive Stimuli
 Stimuli involving events outside the body that stimulate the sensory
receptors
 Examples of exteroceptive stimuli include sounds, sights, smells,
touch sensations, tastes, and the like
Interoceptive Stimuli
 Stimuli inside the body that reflect some change in an internal state
 Examples of interoceptive stimuli include body sensations such as a
full bladder or empty stomach
Razran (1961)
 Conducted a proprioceptive conditioning experiment in which
exteroceptive stimuli (dials) were paired with interoceptive stimuli
(bladder distension)
 Exteroceptive stimuli became CS leading to CR
What stimuli can serve as CSs?

Contextual Stimuli
 The place or environment where training occurs are
readily conditioned
○ Fear of dentist’s office

Temporal Stimuli
 The passage of time since the last US serves as the
CS for the next US
○ Marquis (1941) delayed feeding of infants from
usual 3-hour interval

Circadian Stimuli
 Conditioning of time of day can lead to different CRs
What stimuli can serve as USs?

Stimuli that have either biological significance or
acquired significance work effectively as a US
Basic Phenomena of Conditioning
Acquisition
 Extinction

 Spontaneous Recovery
Generalization
 Discrimination

Basic Phenomena of Conditioning
Acquisition
 When the organism first learns the connection
between the CS and the US, it is said to be in
the stage of acquisition

The initial gain in response strength is large on each
trial, and then it levels out at the end of the acquisition
period. See graph 
Basic Phenomena of Conditioning
Acquisition
 Control Procedures – its important to employ these
conditions to protect against confounding variables
Unpaired Control
 Experimental group gets paired CS-US; control gets CS and
US separately
Truly Random Control
 CS and US are each separately programmed to occur
randomly in time during the experimental sessions along
with the usual pairing of CS-US
Basic Phenomena of Conditioning
 Extinction
 The decline or disappearance of the CR in the
absence of the US
 Presentation of CS alone
Basic Phenomena of Conditioning:
Extinction
US ---------------------------------------------- UR
NS ----------------------------------------------- NO RESPONSE
NS + US -------------------------------------- UR
* This is repeated several times
CS ------------------------------------------------ CR

Extinction process is initiated:
CS -----------------------------------------------
CS -----------------------------------------------
CS -----------------------------------------------
CS -----------------------------------------------

CR
CR (less response than before)
CR (less response than before)
CR (less response than before)
Eventually we get………..
NS --------------------------------------------- NO RESPONSE
(bell)
(no salivation)
Basic Phenomena of Conditioning
Spontaneous Recovery



An extinguished CR will temporarily reappear if after a
time delay the CS is presented again even without the
UCS
This is a reappearance of a CR after extinction despite
no further CS-UCS pairings
Apparently, extinction does not eliminate the CS-US
association; just suppresses it
Trial 11 represents a
two-week rest period 
Spontaneous Recovery
What happens next?
Extinction continues
CS-US pairing
Basic Phenomena of Conditioning
Generalization

After a CR is acquired, stimuli that are similar but not
identical to the CS also will elicit the response
 The greater the similarity between a new stimulus
and the CS the stronger the CR will be
Conditioned to tone of F 
Basic Phenomena of Conditioning
Discrimination

Organisms can be conditioned to learn to
differentiate among similar stimuli
 Even a similar tone will not produce a response in
certain situations
○ For instance, if two tones are continuously
presented but only Tone 1 is paired with the US
then CR will only appear when Tone 1 is presented
The Role of Contiguity
This is the belief that the critical factor in
determining whether or not classical
conditioning would occur was timing
 The most important thing to control in a
classical conditioning experiment was that the
CS and the US should be close together in
time
Does the sequence matter?

Forward Pairing
 CS-US
 Strong conditioning

Simultaneous Pairing
 CS/US
 No conditioning

Backward Pairing
 US-CS
 Weak conditioning
Other factors effecting conditioning

Prior Exposure
 Latent inhibition reduces conditioning effect

Compound CSs
 Usually weaker conditioning to two CSs
conditioned together than when done one at a
time

Surprise
 The Blocking Effect
See next slide 
The Blocking Effect
Kamin (1969)

Experiment 1:
Phase 1
Phase 2
Phase 3
Tone ---- Shock
Tone/Light ----Shock
AM: Tone---?
* This is repeated several times
PM: Light---?
Rescorla-Wagner Model
This model explains the Blocking Effect
Other factors effecting conditioning
CS-US Relevance

Belongingness – the idea that certain CSs
and USs seem to belong together
Belongingness
Procedure
 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 unflavored water producing lights and noise
 A tube of flavored water that was not producing lights and noise
○ Rats are basically given a choice between these two tubes to
drink from
Garcia & Koelling (1966)
Belongingness
Garcia & Koelling (1966)
Results
 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
Interpretation
 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 an example of preparedness
Conditioned Inhibition
A CS becomes associated with the
absence of the US
 For example, knowing when food is
NOT available
Second-Order Conditioning
A new NS can become a new CS
Sensory Preconditioning

Two CSs are paired in first phase with no US
 For example, tone and light

One of the CSs is paired with food in the
second phase
 For example, tone and food

In third phase, the other CS (the one never
paired with the US) is tested
 For example, light

CR is witnessed
Difference between higher order
and sensory preconditioning
The difference is when
the two CSs are paired
 In higher-order
conditioning, the CS2CS1 pairing happens
AFTER the US has been
paired with the CS1
 In sensory
preconditioning, the CS2CS1pairing happens
BEFORE the US has
been paired with the CS1
Preparatory Response
A theory of learning that a different form of
conditioning, instrumental conditioning,
controls the acquisition and performance of
conditioned responses

CR are rewarded (a reinforcement theory)
Learning in the Brain
Cerebellum appears to have the key function
related to the conditioning process
Considered the final destination for association to
take place
 Lesions in this area of the brain prevent tone-toeyeblink conditioning

The Role of Awareness in Conditioning

Early Pavlovian ideas would say awareness
was not necessary for conditioning
 Automatic processes

Conflicting studies
 Some reports of CS-US contingency suggest that
awareness can be a factor
 Secondary tasks are often employed

Sometimes participants in these experiments
report they are aware of CS-US connections
 But this does not correlate with the conditioning that is
actually taking place
Extensions of Conditioning
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

Extensions of Conditioning
Siegel, Hinson, Krank, & McCully (1982)
Demonstrated that classical conditioning
principles might be in effect during druginjecting episodes
 Possible reason for overdoses?

Extensions of Conditioning
Siegel’s theory…

US ---------------------------------------------- UR
(drug)
(anti-drug defenses)

NS ----------------------------------------------- NO RESPONSE
(injection ritual)
(no defenses)
NS + US -------------------------------------- UR
(injection ritual) + (drug)
(anti-drug defenses)
* Repeated several times


CS ----------------------------------------------- CR
(injection ritual)
(anti-drug defenses)
Siegel et al. (1982)
Extensions of Conditioning

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 et al. (1982)
Extensions of Conditioning

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:
 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
Siegel et al. (1982)
So this then gives us 3 main Groups:

Group 1:
 Received heroin in the Colony room (their normal living quarters)
and placebo in the Noisy room the next day

Group 2:
 Received placebo in the Colony room (their normal living quarters)
and heroin in the Noisy room the next day

Group 3:
 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)
Siegel et al. (1982)
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…
 On Day 31:
 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
○ Where they had no previous injections of heroin
 Group 3B were injected with heroin in the Noisy room
○ Where they had no previous injections of heroin
Siegel et al. (1982)
Results: Death Rate



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%)
Siegel et al. (1982)
Results: Death Rate

Results
 50% increase in death rate in new room
 Rats show "room-specific" tolerance

Siegel (1984)
 In a follow-up study, overdose victims who had
survived were interviewed and 70% reported they
had changed environmental conditions
Siegel et al. (1982)
Conditioning with Drug USs
Siegel (1991)
 Reviewed studies that tested conditioning after drug
exposure by replacing the drug with a placebo injection
 Monitoring of body’s conditioned response to the
injection procedure (CS) in the absence of the drug
(US)
 Physiological reactions are sometimes opposite of
what you would expect from receiving the drug
 For example, morphine raises body temperature,
placebo lowers it; morphine reduces pain, placebo
increases pain sensitivity
 This leads to speculation that conditioning can lead to
the development of conditioned responses that are the
opposite of unconditioned responses
Immune System studies..
Ader & Cohen (1975)

Originally intended as a taste aversion experiment
they found some incidental results related to our
immune system response

Rats drank a saccharin solution immediately before the
injection of cyclophosphamide, an immunosuppressive
drug that also has aversive gastrointestinal side effects
Following this pairing, rats avoided drinking the
saccharin solution

Immune System studies
Ader & Cohen (1975)

Results related to immune functioning

The saccharin CS also developed capacity to
suppress immune functioning as a CR
Immune System studies
O'Reilly & Exon (1986)
 These researchers paired a saccharin taste (NS) with the
immunosuppressing cyclophosphamide (UCS)
 One of cyclophosphamide's natural effects is the
reduction of natural killer-cell activity
 Natural killer-cells are one of an organism's first defenses
against the development of malignant tumors
 When they find a cell that has been infected with a virus
or one that has become cancerous, they engulf and
destroy it
 When they presented saccharin to rats, it resulted in a
conditioned taste aversion as well as a conditioned
reduction in natural killer-cell cytotoxicity
Immune System studies
Bovbjerg & Redd (1990)
 Participants
 20 female ovarian cancer patients

Procedure
 Chemotherapy given to patients in hospital setting
 Patients return home within 24-48 hours after
treatment

Hypothesis
 Classically conditioned anticipatory nausea and
vomiting (ANV) and anticipatory immune
suppression (AIS)
Immune System studies

US ------------------------------------------- UR
(chemo)
(nausea/vomiting)

NS -------------------------------------------- NO RESPONSE
(hospital)
(no reaction)

NS + US ----------------------------------- UR
(hospital) (chemo)
(nausea/vomiting)
* This is repeated several times…

CS --------------------------------------------- CR
(hospital)
(nausea/vomiting)
Bovbjerg & Redd (1990)
Immune System studies

US ------------------------------------------- UR
(chemo)
(immunosuppressive)

NS -------------------------------------------- NO RESPONSE
(hospital)
(no reaction)
NS + US ----------------------------------- UR
(hospital) (chemo)
(immunosuppressive)
* This is repeated several times…


CS --------------------------------------------- CR
(hospital)
(immunosuppressive)
Bovbjerg & Redd (1990)
Immune System studies
Results
 Participants experienced both decreased immune function
and increased nausea when they returned to hospital
setting
 Immune suppression occurred after being brought to the
hospital but before the next round of chemotherapy actually
began
 Could the immune suppression be a CR?
 In certain disorders, an overactive immune system
attacks the body and thus suppression becomes a
desirable treatment.
○ Therefore, could a placebo in this case have a
practical application?
Bovbjerg & Redd (1990)
Behavioral Medicine
Implantable cardiac defibrillator (ICD)
delivers electric shock to its users whenever
irregular heart rate occurs
Some report intense shocks that can cause them
to fear places or situations
 Pairing of shock with a variety of CSs

The conditioning theory of phobias…
Watson & Raynor (1920)
 Behavioral psychologists John Watson and grad
assistant Rosalie Raynor taught an 11-month old
infant to become afraid of a gentle white laboratory
rat
Little Albert reacting to mask
worn by John Watson 
This illustrates generalization
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
 Taste-aversion learning

Preparedness leads us to acquire certain fears
that have high survival value
Preparatory-Response Theory
Limitations
 Fears are not limited to preparedness stimuli
 Dental anxiety, etc.
 Fears tend to be age-related
 Young children more easily develop animal fears;
teenagers more easily develop social fears, etc.
Extinction as a therapy…
Exposure treatments can again be utilized to
help treat phobias
Systematic desensitization
 Counterconditioning occurs as phobia (CS) is
paired with US that is incompatible with the phobia

Jones (1924)
 Removed a fear of rabbits in a young child by
pairing ice cream (US) with presentations of the
rabbit (CS)
Credits

Some slides prepared with the help of the following websites:
 http://ibs.derby.ac.uk/~keith/b&b/tolerance.ppt
 http://salmon.psy.plym.ac.uk/year3/DrugAbuse/drugtolerance.htm
 http://drmillslmu.wikispaces.com/file/view/Psych310RomanticRedPr
esentation.ppt
 http://gcuonline.georgian.edu/field_ps432_40/Terry03.htm
 dogsbody.psych.mun.ca/2250/lecture%206.ppt
 people.uncw.edu/dworkins/psy41703ppt/Chapter11.ppt
 www.columbia.edu/cu/.../courses/.../powerpoints/lect5_cc2.ppt