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Join the Psych281 Spring08 group for in-depth discussions on Classical Conditioning by Ivan Pavlov. Learn about US, UR, CS, CR, and more terminology. Discover the basics of conditioning, measuring responses, and factors affecting learning. Dive into first-order and higher-order conditioning, different types of conditioning, and factors influencing the learning process. Engage with other students in exploring the complexities of classical conditioning. Sorry, this group is exclusive to the University of Alberta network.

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  1. 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…)

  2. Chapter 3Classical (Pavlovian) Conditioning

  3. Ivan Petrovich Pavlov (1849-1936) • Pavlovian (Classical) conditioning • Physiologist • Digestion • Dogs • Conditional redirection of reflexes  Conditional reflexes

  4. Conditional?? • Yes, conditional • Mistranslated to conditioned • For learning at least, this is where the term “conditioning” came from

  5. Terminology • Unconditional 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 doesn’t originally elicit the UR (e.g., buzzer) • Conditional response (CR) • The action elicited by the CS (e.g., salivation) • THIS IS LEARNED

  6. The Basics • Use behaviours that are already in place – Reflexes • Associate some new (neutral) stimulus with the stimulus that evokes the reflex • How? 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  CR

  7. The Basics TIME on Conditional Stimulus off on Unconditional Stimulus off (after enough pairings) Conditional Response Unconditional Response

  8. Measuring Conditioning • Sometimes difficult to measure CR • e.g., if CS & US close together, CR & UR can overlap • Buzzer-food-saliva, buzzer-saliva-food? • How long is the separation between the buzzer and the food? • Intensity • Does CR intensity increase with experience? • Test trial (probe trial) • Give CS alone

  9. Probe (Test) Trials TIME on Conditional Stimulus off on Unconditional Stimulus off Conditional Response? No Unconditional Response without the US!

  10. Some notes & examples… • Awareness is NOT necessary • Eyeblink • Conditioned Suppression (Conditioned Emotional Response) • Suppression ratios • Another way of MEASURING conditioning • Taste Aversion • Tequila?

  11. S-S or S-R? • What kind of connection is being made? Response US CS

  12. 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

  13. Results • Less suppression in Habituation group • (In other words, more responding) • Therefore, the connection MUST be S – S

  14. second-order CS first-order CS tone (CS1) food (US) Higher Order Conditioning • S-S-S? • CSs and USs can be associated (First-order) • CSs can be associated with other CSs • Second-order conditioning Light (CS2) salivation (CR)

  15. Types of Conditioning

  16. Types of Conditioning • Delay • Short • Long • Trace • Simultaneous • Backwards • Inhibitory

  17. Delay Conditioning • CS and US overlap • Short • Usually the most effective • Long • timing

  18. Trace Condition • From “memory trace” • Must remember CS • Other stimuli interfere CS GAP US

  19. Simultaneous conditioning • Weaker than short delay • CS can’t signal onset of US • Not predictive CS US

  20. Backwards conditioning • Much more difficult • Ignores order CS US

  21. Conditioned Inhibition • CS- • Up until now, we’ve been talking about CS+ • CS signals the ABSENSE or NON-OCCURRENCE of US • Needs to be some expectation of the US for this to work CS- CS+ US

  22. Factors Affecting Conditioning

  23. Factors that affect conditioning • Contiguity • Contingency • Stimulus Features • Prior Experience • Number of Pairings • Intertrial Interval

  24. Contiguity • Closeness together in time and/or space • Usually, more learning if greater contiguity between CS & US • Type of conditioning may influence this • e.g., eyeblink vs. taste aversion • BUT, contiguity is not sufficient!

  25. Contingency • If-then situation • Consistency of pairing CS and US • Greater contingency, greater learning • informative

  26. Stimulus Features • Intensity of stimuli (CS & US) • Compound Stimuli • Two+ simple CSs presented at the same time • Paired with US • Overshadowing – if one CS is more salient, the other CS may be ignored • Nature of Stimuli (relevance or belongingness) • Loud & noisy water?

  27. Prior experience • Prior experience with CS and/or US affects conditioning • contingency • Latent inhibition • Prior experience with an neutral stimulus makes it harder for it to become a CS later • Novelty • Blocking • Introducing a new CS (CS2) in compound with an already trained CS (CS1) • CS2 won’t be learned about

  28. Sensory preconditioning • Pair two CSs • Pair one with a US • Unpaired CS still elicits CR • Phase 1 (CS1+CS2): • Light + Tone • Light + Tone • Light + Tone • Phase 2 (CS1+US): • Light + Food • Light + Food • Light + Food • Test (CS2?) • Tone? • (measure response)

  29. Number of Pairings • Acquisition curve • Non-linear • Asymptote asymptote CR Strength Conditioning Trials

  30. Intertrial Interval • ITI • Time between each CS-US pairing (i.e., between trials) • Generally, around 30 seconds effective

  31. More conditioning stuff… Extinction, Spontaneous Recovery and Reacquisition

  32. Extinction • Continued pairing of CS with US maintains CR • CS without US --> Extinction • Weakening and stopping of CR • Not forgetting • A type of conditioning • Withhold responding • CS paired with absence of US

  33. Spontaneous Recovery • After extinction, let time pass • Present CS again (no US) • Temporary, small return of CR • Shows extinction is not forgetting!!

  34. Reacquisition • Extinguish CR • Recondition with CS-US pairing • Fewer trials required

  35. Spontaneous Recovery Reacquisition Acquisition Extinction All Together Now! Strength of CR CS&US CS alone CS alone CS&US Trials/Time

  36. Theories How does this all work?

  37. Stimulus Substitution Theory • Pavlov • CR and UR produced by same neural region • Response center • CS takes on properties of US • Substitution Response center US center CS center

  38. Sign Tracking Food

  39. Sign Tracking

  40. But… • CR should be the same as UR • e.g. signtracking, autoshaping • But it’s NOT!! • Intensity, magnitudes • Omissions & additions • Different CSs elicit different CRs • Compensatory responses

  41. Preparatory Response Theory • Learn responses that prepare organism for US occurrence • Sometimes CR same as UR, sometimes different • Drug Tolerance

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