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Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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Page 1: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Chapter 3: Classical Conditioning

PSY 445: Learning & Memory

Page 2: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Pavlovian Conditioning

Pavlov was a research physiologist, not a psychologistAt age 33, earns MDSpends next 20 years

studying the digestive systemRussia’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)

Page 3: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Definition of Classical Conditioning

In classical conditioning, the organism learns a connection between two stimuliIn 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.

ProcedureClassical 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

Page 4: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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

Page 5: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Pavlov’s Paradigm

Pavlov’s Participants

Page 6: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Methods of Studying Classical Conditioning

Eyeblink Conditioning

Skin Conductance Response

Conditioned Taste Aversion

Evaluative Conditioning

Page 7: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Eyeblink ConditioningThe 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 onsetThe 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

Page 8: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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

Page 9: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Conditioned Taste Aversion

Typical ProcedureRats are given novel taste (saccharin-flavored water) is followed by an illness-producing drugGastrointestinal distress Flavored water is again presented

Typical ResultsDecrease or complete avoidance of the flavored water (CS)

Page 10: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Evaluative Conditioning

A change in liking, which occurs due to an association with a positive or negative stimulusNeutral 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

Page 11: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Evaluative Conditioning

Typical ProcedureAn affectively neutral stimulus is presented along with another stimulus that already evokes some type of affective evaluationFor example, a word (NS) is paired with an bad odor (US)Typical ResultsEmotional tone of the neutral stimulus will change to correspond to the USThe word (CS) will come to evoke a negative feeling (CR) from the person who has gone through this type of conditioning

Page 12: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Evaluative Conditioning

Hammerl, Bloch, & Silverthorne (1997)

ProcedureScenic pictures were pre-ratedPictures that were originally rated as neutral (NS) were then paired (five trials) with either pictures that were rated low or rated high (US)ResultsWhen 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 beforeThus, the originally neutral pictures become the CS and the resultant ratings of these pictures become the CR

Page 13: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Evaluative Conditioning

LimitationsDoesn’t fit classical conditioning pardigm

completelyReliance just on verbal reports is questionableSome believe the changed preferences are based

on conscious knowledge; not automatic responses

Page 14: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

What stimuli can serve as CSs?Exteroceptive Stimuli Stimuli involving events outside the body that stimulate the sensory receptorsExamples of exteroceptive stimuli include sounds, sights, smells, touch sensations, tastes, and the likeInteroceptive Stimuli Stimuli inside the body that reflect some change in an internal stateExamples of interoceptive stimuli include body sensations such as a full bladder or empty stomach

Page 15: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

What stimuli can serve as CSs? Contextual Stimuli

The place or environment where training occurs are readily conditioned○ Fear of dentist’s office

Temporal StimuliThe 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

Page 16: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

What stimuli can serve as USs? Stimuli that have either biological significance or

acquired significance work effectively as a US

Page 17: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Basic Phenomena of Conditioning

Acquisition Extinction

Spontaneous Recovery

Generalization Discrimination

Page 18: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Basic Phenomena of Conditioning

AcquisitionWhen 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

Page 19: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Basic Phenomena of Conditioning

AcquisitionControl Procedures – its important to employ these conditions to protect against confounding variables

Unpaired ControlExperimental group gets paired CS-US; control gets CS and US separately

Truly Random ControlCS and US are each separately programmed to occur randomly in time during the experimental sessions along with the usual pairing of CS-US

Page 20: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Basic Phenomena of Conditioning

ExtinctionThe decline or disappearance of the CR in the

absence of the USPresentation of CS alone

Page 21: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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 ----------------------------------------------- CRCS ----------------------------------------------- CR (less response than before)CS ----------------------------------------------- CR (less response than before)CS ----------------------------------------------- CR (less response than before)

Eventually we get………..

NS --------------------------------------------- NO RESPONSE (bell) (no salivation)

 

Page 22: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Basic Phenomena of ConditioningSpontaneous RecoveryAn extinguished CR will temporarily reappear if after a time delay the CS is presented again even without the UCSThis is a reappearance of a CR after extinction despite no further CS-UCS pairingsApparently, extinction does not eliminate the CS-US association; just suppresses it

Trial 11 represents a two-week rest period

Page 23: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Spontaneous Recovery

What happens next?

Extinction continues CS-US pairing

Page 24: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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

Page 25: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Basic Phenomena of ConditioningDiscrimination

Organisms can be conditioned to learn to differentiate among similar stimuliEven 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

Page 26: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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

Page 27: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Does the sequence matter? Forward Pairing

CS-USStrong conditioning

Simultaneous PairingCS/USNo conditioning

Backward PairingUS-CSWeak conditioning

Page 28: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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

SurpriseThe Blocking Effect

See next slide

Page 29: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

The Blocking EffectThe Blocking Effect 

Experiment 1:

Phase 1 Phase 2 Phase 3

 

Tone ---- Shock Tone/Light ----Shock AM: Tone---?

* This is repeated several timesPM:

Light---?

Kamin (1969)Kamin (1969)

Page 30: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Rescorla-Wagner Model

This model explains the Blocking Effect

Page 31: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Other factors effecting conditioning

CS-US RelevanceBelongingness – the idea that certain CSs and USs seem to belong together

Page 32: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

BelongingnessProcedureRats 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)

Page 33: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

BelongingnessResultsGroup 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

InterpretationEvidently, 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  

Garcia & Koelling (1966)

Page 34: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Conditioned Inhibition

A CS becomes associated with the absence of the USFor example, knowing when food is NOT available

Page 35: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Second-Order ConditioningA new NS can become a new CS

Page 36: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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 phaseFor example, tone and food

In third phase, the other CS (the one never paired with the US) is testedFor example, light

CR is witnessed

Page 37: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Difference between higher order and sensory preconditioning

The difference is when the two CSs are pairedIn higher-order conditioning, the CS2-CS1 pairing happens AFTER the US has been paired with the CS1In sensory preconditioning, the CS2-CS1pairing happens BEFORE the US has been paired with the CS1

Page 38: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Preparatory Response

A theory of learning that a different form of conditioning, instrumental conditioning, controls the acquisition and performance of conditioned responsesCR are rewarded (a reinforcement theory)

Page 39: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Learning in the Brain

Cerebellum appears to have the key function related to the conditioning processConsidered the final destination for association to take placeLesions in this area of the brain prevent tone-to-eyeblink conditioning

Page 40: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

The Role of Awareness in Conditioning Early Pavlovian ideas would say awareness

was not necessary for conditioning Automatic processes

Conflicting studiesSome reports of CS-US contingency suggest that

awareness can be a factorSecondary 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

Page 41: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Extensions of Conditioning

Drug ToleranceDrugs have less of an effect when taken repeatedly (less of a high)Drug users crave more of the drug despite its lessening effectsIt appears that certain drugs trigger our body to call upon its defenses against the effects of the drug

Page 42: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Extensions of Conditioning

Siegel, Hinson, Krank, & McCully (1982)Demonstrated that classical conditioning principles might be in effect during drug-injecting episodesPossible reason for overdoses?

Page 43: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Extensions of Conditioning

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’s theory…

Siegel et al. (1982)

Page 44: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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)

Page 45: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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 ACFor others: heroin in AC; placebo in WNControl group received only placebo in different rooms on

alternate days

Siegel et al. (1982)

Page 46: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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)

Page 47: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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)

Page 48: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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)

Page 49: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Results: Death Rate

Results50% increase in death rate in new roomRats 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)

Page 50: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Conditioning with Drug USs

Siegel (1991)Reviewed studies that tested conditioning after drug exposure by replacing the drug with a placebo injectionMonitoring 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 drugFor example, morphine raises body temperature, placebo lowers it; morphine reduces pain, placebo increases pain sensitivityThis leads to speculation that conditioning can lead to the development of conditioned responses that are the opposite of unconditioned responses

Page 51: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Immune System studies..

Ader & Cohen (1975)Originally intended as a taste aversion experiment they found some incidental results related to our immune system responseRats drank a saccharin solution immediately before the injection of cyclophosphamide, an immunosuppressive drug that also has aversive gastrointestinal side effectsFollowing this pairing, rats avoided drinking the saccharin solution

Page 52: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Immune System studiesAder & Cohen (1975)Results related to immune functioningThe saccharin CS also developed capacity to suppress immune functioning as a CR

Page 53: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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

Page 54: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Immune System studiesBovbjerg & Redd (1990)Participants

20 female ovarian cancer patientsProcedure

Chemotherapy given to patients in hospital settingPatients return home within 24-48 hours after

treatmentHypothesis

Classically conditioned anticipatory nausea and vomiting (ANV) and anticipatory immune suppression (AIS)

Page 55: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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)

Page 56: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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)

Page 57: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Immune System studiesResultsParticipants experienced both decreased immune function and increased nausea when they returned to hospital settingImmune 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)

Page 58: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Behavioral Medicine

Implantable cardiac defibrillator (ICD) delivers electric shock to its users whenever irregular heart rate occursSome report intense shocks that can cause them to fear places or situationsPairing of shock with a variety of CSs

Page 59: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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

Page 60: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Preparatory-Response Theory

The purpose of CR is to prepare organism for the UCSThe dog salivates to the tone so as to get ready for

the presentation of the foodThe rat freezes in response to the light so it is ready

for the painful shockTaste-aversion learning

Preparedness leads us to acquire certain fears that have high survival value

Page 61: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Preparatory-Response Theory

LimitationsFears 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.

Page 62: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

Extinction as a therapy…Exposure treatments can again be utilized to help treat phobiasSystematic desensitizationCounterconditioning 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)

Page 63: Chapter 3: Classical Conditioning PSY 445: Learning & Memory

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/

Psych310RomanticRedPresentation.ppt http://gcuonline.georgian.edu/field_ps432_40/Terry03.htm dogsbody.psych.mun.ca/2250/lecture%206.ppt people.uncw.edu/dworkins/psy41703ppt/Chapter11.pptwww.columbia.edu/cu/.../courses/.../powerpoints/lect5_cc2.ppt