C 82 MPR Practical Methods 2 Dr Mark

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C 82 MPR – Practical Methods 2 Dr Mark Haselgrove Blocking and Associative learning

C 82 MPR – Practical Methods 2 Dr Mark Haselgrove Blocking and Associative learning Please log in with Windows 7

Structure of the Practical Week 1: Introduction to the topic, background information Homework: Reading

Structure of the Practical Week 1: Introduction to the topic, background information Homework: Reading Week 2: Further background. Set up Experiment Homework: Test Participants Week 3: Introduction to Excel and SPSS, data exploration Homework: Test more participants and explore data Week 4: Data analysis, Introduction to Power. Point, begin preparing presentations Homework: Prepare presentation Week 5: Present your finding, Q & A Homework: Write-up practical report. Hand in by 4 pm, 7 th April

Conditioning and Learning A reminder of some terminology and facts… Unconditioned Stimulus (US): Biologically

Conditioning and Learning A reminder of some terminology and facts… Unconditioned Stimulus (US): Biologically significant event (e. g. food, pain) Unconditioned Response (UR): The response evoked by the US Conditioned stimulus (CS): Previously neutral stimulus (e. g. tone) that acquires a response by being paired with a US Conditioned response (CR): The response evoked by the CS Clicker → (CS) → Shock Jumping → Jumping (US) (CR) → (UR)

Conditioning and Learning Hebb (1949) Pairing a CS with a US is sufficient for

Conditioning and Learning Hebb (1949) Pairing a CS with a US is sufficient for learning to take place Event Sensory register CS US US Response generator CS CS-US CS Learning mechanism US “Whatever fires together, wires together” Observed behaviour

Conditioning and Learning Kamin (1968) Shock conditioning experiment with rats No fear of the

Conditioning and Learning Kamin (1968) Shock conditioning experiment with rats No fear of the Light Group Stage 1 Stage 2 Test Blocking Noise → Shock Noise & Light → Shock Light Control - Only learn about a CS if it followed by A SURPRISING US Lots of fear of the Light

Conditioning and Learning Other examples of blocking…. Waelti, Dickinson & Schultz (2001): Blocking in

Conditioning and Learning Other examples of blocking…. Waelti, Dickinson & Schultz (2001): Blocking in Macaques Monkeys expressed more interest in Y than X Stage 1 Picture A → Juice Stage 2 Test Pictures A & X → Juice X vs Y Picture B → no Juice Pictures B & Y → Juice

Conditioning and Learning Other examples of blocking…. Le. Pelley, Oakshott & Mc. Laren (2005)

Conditioning and Learning Other examples of blocking…. Le. Pelley, Oakshott & Mc. Laren (2005) Blocking in Cambridge undergraduates Stage 1 Stage 2 Test Food A & X → Illness Food A → Illness X vs Y Food C & Y → Illness Participants rated X as safer than Y

Conditioning and Learning Rescorla & Wagner (1972) - A mathematical theory of learning and

Conditioning and Learning Rescorla & Wagner (1972) - A mathematical theory of learning and surprise CS US Learning = intensity of CS x intensity of US x surprisingness of US ΔV = α x β Surprise = The difference between what you get and what you expect to get x (λ - ΣV)

Conditioning and Learning Rescorla & Wagner model applied to blocking: ΔV = α x

Conditioning and Learning Rescorla & Wagner model applied to blocking: ΔV = α x β x (λ - ΣV) Group Stage 1 Stage 2 Test Blocking A → US AX → US X Control - AX → US X A US X

Conditioning and Learning Your turn… ΔV = α x β x (λ - ΣV)

Conditioning and Learning Your turn… ΔV = α x β x (λ - ΣV) Stage 1 Stage 2 Test A → US AX → US X

Conditioning and Learning Surprise brought about by a QUALITATIVE change in the US Bakal,

Conditioning and Learning Surprise brought about by a QUALITATIVE change in the US Bakal, Johnson & Rescorla (1974) – Conditioned fear in rats Group Stage 1 Stage 2 Test Blocking A → shock AX → Loud Noise X Control - AX → Loud Noise X When blocking persists, despite a qualitatitive change in the nature of the US, we call the effect: TRANS-REINFORCER BLOCKING More fear X in Control group than Blocking group:

Conditioning and Learning Surprise brought about by a QUALITATIVE change in the US Stickney

Conditioning and Learning Surprise brought about by a QUALITATIVE change in the US Stickney & Donahoe (1983) – Eye blink conditioning in rabbits Group Stage 1 Stage 2 Test Blocking A → left shock AX → right shock X Control - AX → right shock X When blocking disappears, with a qualitatitive change in the nature of the US, we call the effect: TRANS-REINFORCER UN-BLOCKING Conditioned eye blink to X in both groups: UN-BLOCKING

Conditioning and Learning How do we explain this discrepancy in the literature? Bakal et

Conditioning and Learning How do we explain this discrepancy in the literature? Bakal et al (1974) – Conditioned fear in rats (TRB) Stickney & Donahoe (1983) – Eye blink conditioning in rabbits (TRu. B) Could be an effect of: (1) different species, (2) different experimental procedure, (3) different apparatus, (4) different measure of behaviour. Betts, Brandon & Wagner (1996) – Blocking in rabbits No blocking when eye blink conditioning was measured But, blocking was observed when “startle” was measured HOMEWORK: Read: Betts, Brandon & Wagner (1996) Paper to be found on Mark Haselgrove’s website

References Bakal, C. W. , Johnson, R. D. , & Rescorla, R. A. (1974).

References Bakal, C. W. , Johnson, R. D. , & Rescorla, R. A. (1974). The effect of change in US quality on the blocking effect. Pavlovian Journal, 9, 97 -103. Betts, S. L. , Brandon, S. E. , & Wagner, A. R. (1996). Dissociation of the blocking of conditioned eyeblink and conditioned fear following a shift in US locus. Animal Learning & Behavior, 24(4), 459 -470. Hebb, D. O. (1949). The organisation of behaviour. New York: Wiley. Kamin, L. J. (1968). Attention-like processes in classical conditioning. In M. R. Jones (Ed. ), Miami symposium on the prediction of behvior: Aversive stimulation (pp. 9 -32). Coral Gables, Fl: University of Miami Press. Le Pelley, M. E. , Oakeshott, S. M. , & Mc. Laren, I. P. L. (2005). Blocking and unblocking in human causal learning. Journal of Experimental Psychology-Animal Behavior Processes, 31(1), 56 -70. Rescorla, R. A. , & Wagner, A. R. (1972). A theory of Pavlovian learning: Variations in the effectiveness of reinforcement and nonreinforcement. In A. H. Black & W. F. Prokasy (Eds. ), Classical Conditioning II (pp. 64 -99). New York: Appleton-Century-Crofts. Stickney, K. J. , & Donahoe, J. W. (1983). Attenuation of Blocking by a Change in Us Locus. Animal Learning & Behavior, 11(1), 60 -66. Waelti, P. , Dickinson, A. , & Schultz, W. (2001). Dopamine responses comply with basic assumptions of formal learning theory. Nature, 412, 43 -48.