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49 milliamp group weak or a 085 milliamp group strong

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Unformatted text preview: ower Small US (λ) (2) Ultimate level of conditioning is less 22 Rescorla–Wagner model US intensity The acquisition of conditioned suppression to a noise conditioned stimulus (CS) by two groups of rats that received either a 0.49 milliamp (Group Weak) or a 0.85 milliamp (Group Strong) shock unconditioned stimulus (US) (adapted from Annau & Kamin, 1961). Rescorla–Wagner model CS intensity - Variations in the intensity of the CS are simulated by varying the value of α Intense CS = High value of α (e.g. 1) Weak CS = Low value of α (e.g. just > 0) - Varying the value of α only influences the rate of conditioning, not maximum learning - Kamin & Schaub (1963), using a conditioned suppression procedure with rats confirmed faster conditioning with a 81 dB noise than a 49 dB noise, but no differences in the ultimate level of conditioning. (adapted from Kamin & Schaub, 1963). 24 Rescorla–Wagner model Conditioning with a compound CS -  When two or more stimuli are presented in compound e.g. A and X, their associative strengths are summed (VALL) to determine CR: VALL = VA +VX -  VALL determines the changes in associative strength on each trial: ΔV = α(λ-VALL) -  Thus, change in associative strength determined by the discrepancy between the combined associative strengths of all stimuli present and λ 25 Rescorla–Wagner model Conditioning with a compound CS Blocking Group Element conditioning Compound conditioning Test Group E Noise → Shock Noise & Light → Shock Light Group C - Noise & Light → Shock Light - V Noise = λ after the element conditioning for Group E Therefore (λ-VALL) = 0 during compound conditioning -  No increments in associative strength will take place to the light Overshadowing -  After compound conditioning in Group C, V Noise + V Light = λ -  Therefore V Noise or V Light alone < λ - Conditioning to the light alone would result in V Light = λ 26...
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