The Neurobiology of Learning and Memory

Lecture OutlineConditioned ExcitationContiguity Delay, trace, simultaneous, backward pairsISI functionExtinctionInhibition (Out of Order)Pavlovian CI w/discrete trialsRescorlas Two TestsNegative CS-US Contingency; Differential InhibitionCompound ConditioningStimulus CompetitionOvershadowingBlocking (surprise!)Contingency (several paradigms), and stimulus choice

1What is Pavlovian Conditioning?

Conditioned stimulus: examples = tone, bell, lightUnconditioned stimulus: e.g., food, shock, waterUnconditioned response: no learning requiredConditioned response: based on experience; doesnt require US2C:\Figures\Chapter04\high-res\Alcock8e-ChOpener-04.jpg

Learning to Predict an Important Event (the US)Acquisition of Conditioned Excitationshape of function is importantnegatively-accelerated growth functionlearn most early less laterwhat generates the asymptote? (2 things!)% CR3Temporal arrangement of Pavlovian conditioning trialsSee Figure 4.4

CS-US Inter-Stimulus Interval (ISI) & Typical Learning Success

Optimal = 0.5 2 sec ISIContiguity matters!

See Figure 4.5Lecture OutlineConditioned ExcitationContiguity Delay, trace, simultaneous, backward pairsISI functionExtinctionInhibition (Out of Order)Pavlovian CI w/discrete trialsRescorlas Two TestsNegative CS-US Contingency; Differential InhibitionCompound ConditioningStimulus CompetitionOvershadowingBlocking (surprise!)Contingency (several paradigms), and stimulus choice

6Learning When the US Isnt PresentExtinction of Conditioned Excitation% CRDesign and graph drawn in class7Lecture OutlineConditioned ExcitationContiguity Delay, trace, simultaneous, backward pairsISI functionExtinctionInhibition (Out of Order)Pavlovian CI w/discrete trialsRescorlas Two TestsNegative CS-US Contingency; Differential InhibitionCompound ConditioningStimulus CompetitionOvershadowingBlocking (surprise!)Contingency (several paradigms), and stimulus choice

8Pavlovian Conditioning Procedures

Note: CS+/CS may refer to cues that predict US/noUStrials that end in US/noUSLearning About the Absence of the USTraining Conditioned InhibitionToneFoodLight/ToneNoFood% CRGraph drawn in class10Learning About the Absence of the USPhase 1Phase 2 . ToneFood ToneFood Light/ToneNoFood% CRPhase 1 Phase 2Note: Sometimes experimenters train the CS+ prior to adding the CSGraph drawn in class11Lecture OutlineConditioned ExcitationContiguity Delay, trace, simultaneous, backward pairsISI functionExtinctionInhibition (Out of Order)Pavlovian CI w/discrete trialsRescorlas Two TestsNegative CS-US Contingency; Differential InhibitionCompound ConditioningStimulus CompetitionOvershadowingBlocking (surprise!)Contingency (several paradigms), and stimulus choice

12True Conditioned InhibitionProb w/ inhibition = lack of responseReduce responding to other cueBUT, no response to inhibitorWhat if attentional? (distracting?)

Rescorla (1969) 2 tests for conditioned inhibitionSummation test (aka, Compound-Stimulus test / Transfer test)Retardation test

13True Conditioned InhibitionSummation Test for Conditioned Inhibition

Training PhaseTesting Phase ToneFoodTone? Light/Tone?Light/ToneNoFoodBuzz? Light/Buzz?BuzzerFoodLight?% CRGraph drawn in class14True Conditioned InhibitionRetardation Test for Conditioned Inhibition

Training Phase Retardation Phase ToneFoodLightFoodLight/ToneNoFood% CRGraph drawn in class15Negative CS-US Contingency

Tangent: Are Inhibitors Bad Stimuli??17The Value of Predictability

Predictable attack results in reduction of general anxiety level.18FIGURE 1.8 In the Pavlovian conditioning method, two events called the CS and US are presented together. Subsequently, the CS evokes the response called the CR. Psychologists assume that the CS evokes the CR because the CS gets associated with the US. Psychologists and neurobiologists continue to use this method to study associative learning in animals.Lecture OutlineConditioned ExcitationContiguity Delay, trace, simultaneous, backward pairsISI functionExtinctionInhibition (Out of Order)Pavlovian CI w/discrete trialsRescorlas Two TestsNegative CS-US Contingency; Differential InhibitionCompound ConditioningStimulus CompetitionOvershadowingBlocking (surprise!)Contingency (several paradigms), and stimulus choice

19Compound ConditioningTraining with multiple cues on same trialRescorlas conditioned inhibition (LT trial)

Stimulus CompetitionOvershadowingBlocking

20OvershadowingTraining Phase Testing Phase LIGHT/toneFoodLIGHT/tone?Light? Tone?% CRGraph drawn in class(also, control group!)21Blocking% CRPredictive ValueDesign and graph drawn in class22

A Real-World Example of BlockingCompetition in learning to read

What we want our kids to learn

horse23

Real-World Example of BlockingCompetition in learning to read

Early on:Later:

horsehorse24Lecture OutlineConditioned ExcitationContiguity Delay, trace, simultaneous, backward pairsISI functionExtinctionInhibition (Out of Order)Pavlovian CI w/discrete trialsRescorlas Two TestsNegative CS-US Contingency; Differential InhibitionCompound ConditioningStimulus CompetitionOvershadowingBlocking (surprise!)Contingency (several paradigms), and stimulus choice

25Other Effects of the US (present or absent)ContingencyUnsignaled USs Trials without USsExtinctionConditioned InhibitionLatent InhibitionSensory Pre-ConditioningHigher-Order ConditioningPositive PatterningNegative Patterning

26ContingencyPredictive value mattersCS/US contingency

CSUS27Contingency

28Other Effects of the US (present or absent)ContingencyUnsignaled USs Trials without USsExtinctionConditioned InhibitionLatent InhibitionSensory Pre-ConditioningHigher-Order ConditioningPositive PatterningNegative Patterning

Experimentaldesigns and graphsfor these paradigmsdiscussed in class.29Higher-Order Conditioning

30Higher-Order Conditioning

Sexy ImagesSex!Sexy ImagesGuessPerformersFun!PerformersJunkFearful LooksPain!Fearful LooksFear Stimuli31The Value of Predictability

Predictable attack results in reduction of general anxiety level.32FIGURE 1.8 In the Pavlovian conditioning method, two events called the CS and US are presented together. Subsequently, the CS evokes the response called the CR. Psychologists assume that the CS evokes the CR because the CS gets associated with the US. Psychologists and neurobiologists continue to use this method to study associative learning in animals.