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Facebook Group:. The group is called: Psych281 Spring08 Available only to University of Alberta network Sorry to be rude but… Please don’t add me as a friend (avoiding any kind of favoritism, etc…). Chapter 3 Classical (Pavlovian) Conditioning. Ivan Petrovich Pavlov (1849-1936). - PowerPoint PPT Presentation

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Chapter 3 Classical Conditioning

Facebook Group:The group is called:Psych281 Spring08Available only to University of Alberta network

Sorry to be rude butPlease dont add me as a friend (avoiding any kind of favoritism, etc)Chapter 3Classical (Pavlovian) ConditioningIvan Petrovich Pavlov (1849-1936)Pavlovian (Classical) conditioningPhysiologistDigestionDogsConditional redirection of reflexes Conditional reflexes

Conditional??Yes, conditionalMistranslated to conditionedFor learning at least, this is where the term conditioning came from

TerminologyUnconditional stimulus (US)Stimulus that elicits the innate reflex (e.g., food)Unconditional response (UR)Reflex action that occurs in response to US (e.g., salivation)Conditional stimulus (CS)Any stimulus that doesnt originally elicit the UR (e.g., buzzer)Conditional response (CR)The action elicited by the CS (e.g., salivation)THIS IS LEARNED

The BasicsUse behaviours that are already in place ReflexesAssociate some new (neutral) stimulus with the stimulus that evokes the reflexHow? Present them together!Buzzer-food (salivate)Buzzer-food (salivate)Buzzer-food (salivate)Buzzer-?

- CS-US UR- CS-US (CR) UR- CS-US (CR) UR- CS CRThe BasicsTIMEConditional StimulusonoffUnconditional StimulusonoffUnconditional Response(after enough pairings)Conditional ResponseMeasuring ConditioningSometimes difficult to measure CRe.g., if CS & US close together, CR & UR can overlapBuzzer-food-saliva, buzzer-saliva-food?How long is the separation between the buzzer and the food?IntensityDoes CR intensity increase with experience?Test trial (probe trial)Give CS aloneProbe (Test) TrialsTIMEConditional StimulusonoffUnconditional StimulusonoffNo Unconditional Response without the US!Conditional Response?Some notes & examplesAwareness is NOT necessaryEyeblinkConditioned Suppression (Conditioned Emotional Response)Suppression ratiosAnother way of MEASURING conditioningTaste AversionTequila?

S-S or S-R?USCSResponseWhat kind of connection is being made?Rescorla (1973)So, how do you get rid of a response that is hard wired to a stimulus?How can you get rid of a reflex?Habituation

ResultsLess suppression in Habituation group(In other words, more responding)Therefore, the connection MUST be S S

GroupPhase 1Phase 2TestHabituationL N (startle)Noise (habituate)LightControlL N (startle)NothingLightHigher Order ConditioningS-S-S?CSs and USs can be associated (First-order)CSs can be associated with other CSsSecond-order conditioning

salivation (CR)first-order CStone (CS1)food (US)second-order CSLight (CS2)Types of ConditioningTypes of ConditioningDelayShortLongTraceSimultaneousBackwardsInhibitoryDelay ConditioningCS and US overlapShortUsually the most effective

LongtimingTrace ConditionFrom memory traceMust remember CSOther stimuli interfere

CSUSGAPSimultaneous conditioningWeaker than short delayCS cant signal onset of USNot predictive

CSUSBackwards conditioningMuch more difficultIgnores orderCSUSConditioned InhibitionCS-Up until now, weve been talking about CS+CS signals the ABSENSE or NON-OCCURRENCE of USNeeds to be some expectation of the US for this to workCS+USCS-Factors Affecting ConditioningFactors that affect conditioningContiguityContingencyStimulus FeaturesPrior ExperienceNumber of PairingsIntertrial IntervalContiguityCloseness together in time and/or spaceUsually, more learning if greater contiguity between CS & USType of conditioning may influence thise.g., eyeblink vs. taste aversion

BUT, contiguity is not sufficient! GroupCS-US pairingsUS aloneCR strengthA.400Very strongB.40.10strongC.40.20MediumD.40.40weakContingencyIf-then situationConsistency of pairing CS and USGreater contingency, greater learninginformative

Stimulus FeaturesIntensity of stimuli (CS & US)Compound StimuliTwo+ simple CSs presented at the same timePaired with USOvershadowing if one CS is more salient, the other CS may be ignoredNature of Stimuli (relevance or belongingness)Loud & noisy water?

Prior experiencePrior experience with CS and/or US affects conditioningcontingencyLatent inhibitionPrior experience with an neutral stimulus makes it harder for it to become a CS laterNoveltyBlockingIntroducing a new CS (CS2) in compound with an already trained CS (CS1)CS2 wont be learned aboutSensory preconditioningPair two CSsPair one with a USUnpaired CS still elicits CR

Phase 1 (CS1+CS2):Light + ToneLight + ToneLight + Tone

Phase 2 (CS1+US):Light + FoodLight + FoodLight + Food

Test (CS2?)Tone?(measure response)

Number of PairingsAcquisition curveNon-linearAsymptote

Conditioning TrialsCR StrengthasymptoteIntertrial IntervalITITime between each CS-US pairing (i.e., between trials)Generally, around 30 seconds effective

More conditioning stuffExtinction, Spontaneous Recovery and ReacquisitionExtinctionContinued pairing of CS with US maintains CRCS without US --> ExtinctionWeakening and stopping of CRNot forgettingA type of conditioningWithhold respondingCS paired with absence of US

Spontaneous RecoveryAfter extinction, let time passPresent CS again (no US)Temporary, small return of CRShows extinction is not forgetting!!

ReacquisitionExtinguish CRRecondition with CS-US pairingFewer trials required

All Together Now!Trials/TimeStrength of CRAcquisitionExtinctionSpontaneous RecoveryReacquisitionCS&USCS aloneCS aloneCS&USTheoriesHow does this all work?Stimulus Substitution TheoryPavlovCR and UR produced by same neural regionResponse centerCS takes on properties of USSubstitution

UScenterCScenterResponsecenterSign Tracking

FoodSign Tracking

ButCR should be the same as URe.g. signtracking, autoshapingBut its NOT!!Intensity, magnitudesOmissions & additionsDifferent CSs elicit different CRsCompensatory responses

Preparatory Response TheoryLearn responses that prepare organism for US occurrenceSometimes CR same as UR, sometimes differentDrug Tolerance