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Contemporary Learning Theory PowerPoint Presentation
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Contemporary Learning Theory

Contemporary Learning Theory

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Contemporary Learning Theory

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    1. Contemporary Learning Theory Dr Pam Blundell Lecture Eight

    2. Today Discuss issues related to learning about neutral stimuli Sensory pre-conditioning Second-order conditioning Acquired distinctiveness + equivalence Introduction to perceptual learning

    3. Objectives At the end of this lecture, students should be able to: Discuss empirical evidence concerning learning about neutral events Assess the implications of this empirical evidence on existing theories of learning

    4. Reading Ward-Robinson, J., Symonds, M., & Hall, G. (1998). Context specificity of sensory preconditioning: Implications for processes of within-event learning. AL&B, 26, 225. Barnet, R. C., Cole, R. P., & Miller, R. R. (1997). Temporal integration in second-order conditioning and sensory preconditioning. AL&B, 25, 221

    5. Learning about neutral events Much of our work so far has examined learning about reinforcers/biologically significant events Many events in the world have no innate biological significance Do we learn about them?

    6. Sensory preconditioning A?X X+ A? Or A?X X+ A? B?Y Y- B?

    7. Sensory preconditioning CR elicited to A Conditioned suppression (Rizley & Rescorla, 72) HR conditioning in rabbits (Pfautz etal 1978) Flavour aversion conditioning in rats (Rescorla and Cunningham, 1978)

    8. Rescorla & Cunningham 1978

    9. Associative analysis

    10. Associative analysis SPC occurs via associative chain

    11. Alternatively

    12. Rescorla & Freberg (1978) 1: AB B B+ A? 2: AB A B+ A? 3: AB -- B+ A? Poor SPC found with both groups 1 and 2 Suggests the BA association may be important?

    13. Ward-Robinson & Hall (1996) Effect of backward pairings (explicit test of role of backward associations)

    15. If associatively activated representations can be learned about, then A? no shock should extinguish the X?shock association, as A will activate X representation.

    17. Sensory preconditioning Importance of associatively activated representations in learning Associative chain

    18. Second order conditioning X ? US A?X CRs to X emerge Extinction of X?US reduces CR

    19. Second order conditioning Rizley and Rescorla (1972) Similar experiment to Roshotte et al Found that extinction did not change responding in conditioned suppression procedure

    20. Mediated conditioning account

    21. S-R account

    22. How to discriminate these accounts Food devaluation! Holland & Rescorla 1975 A? food; X?A; food?LiCl; X? Animals continue responding to X Responding not mediated by representation of food

    23. Second-order conditioning A range of associations may form Depends upon parameters? Actually quite difficult to find in the lab

    24. Associative model Assume presenting a CS activates a corresponding CS node Assume presenting a US activates a corresponding US node Little said about how these nodes may come to be activated? Can it change with experience??

    25. Acquired equivalence & distinctiveness

    27. Acquired equivalence

    28. Acquired equivalence

    29. Acquired distinctiveness

    30. Perceptual learning Gibson & Walk (1956) Rats raised from birth in cages with white walls, against which were displayed black metal shapes (circles & triangles) At 90 days old, trained on food rewarded discrimination between circle and triangle Those pre-exposed were better at the discrimination than control animals

    32. Perceptual learning Non-reinforced pre-exposure aided discrimination between circles and triangles Some problems of replication in subsequent experiments Seems to be to do with the specific stimuli used Only helps difficult discriminations?

    33. Perceptual learning Gibson & Walk suggested differentiation was the cause of Perceptual learning

    34. Summary Animals learn about non-reinforced pairings Animals can learn about associatively evoked images of stimuli Representations of stimuli may change through learning