324 03 part 3.1 classical conditioning mechanisms
This document discusses several mechanisms of respondent conditioning: 1) Contingency and contiguity play a role in conditioning - the likelihood of the unconditioned stimulus occurring with or without the conditioned stimulus affects conditioning. Shorter time intervals between stimuli also strengthen conditioning. 2) Compound stimuli, using two or more cues together and then pairing with the unconditioned stimulus, often conditions responses to both cues. 3) Blocking occurs when a stimulus is conditioned to one cue, preventing further conditioning to another cue presented with the first. 4) Overshadowing happens when a more salient cue reduces conditioning to a less intense cue. Prior experience without the unconditioned stimulus (latent inhibition) also weakens future
324 03 part 3.1 classical conditioning mechanisms
- 1. Human Learning Topic 3: Part 3 Respondent Conditioning Mechanisms and Function CEDP 324 Ryan Sain, Ph.D. 1 3/30/2012
- 2. Contingency & Contiguity Contingency is a major key! the degree of prediction from the CS to the US effects the amount of conditioning Rescorla – p(us/cs) and p(us/no cs) Vary these probabilities using a 2 minute tone at random intervals .4 that the US would occur during a CS; .2 a US would occur during a no CS Contiguity also plays a role The shorter the ISI or TI the stronger the conditioning CEDP 324 Ryan Sain, Ph.D. 2 3/30/2012
- 3. Compound Stimuli Two or more stimuli occurring together (sound and sight - CR) then paired with a US Can test the effects of this by presenting one of the CSs alone after pairings Often you get conditioning to both But not always CEDP 324 Ryan Sain, Ph.D. 3 3/30/2012
- 4. Blocking Kamin – conditioned suppression procedure (css = light, tone, light tone; cr = shock) Two groups: blocking and control One stimulus seems to block conditioning to the other – no new predictability. Group Phase 1 Phase 2 Test Result Phase Blocking 1 Light Light/tone Tone Tone elicits no CR Control ------- Light/tone Tone Tone elicits CR CEDP 324 Ryan Sain, Ph.D. 4 3/30/2012
- 5. Overshadowing Intensity of the CS effects conditioning trials Loud CS and soft CS US = CR Test with either CS +CS = CR -CS ≠ CR But you can then use the –CS by itself and get conditioning One seems to overshadow the other CEDP 324 Ryan Sain, Ph.D. 5 3/30/2012
- 6. Experience with the CS Latent inhibition Presence of a CS in the absence of the US Delays acquisition in the future Prediction is decreased CEDP 324 Ryan Sain, Ph.D. 6 3/30/2012
- 7. Acquisition • CR is increasing in strength Strength of CR •Learn more on early trials than on later ones Number of trials CEDP 324 Ryan Sain, Ph.D. 7 3/30/2012