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Factors Influencing Conditioning

Factors Influencing Conditioning. CS and US Intensity, and Attention to the CS Temporal relationship Predictiveness Preparedness Redundancy. 1. CS Intensity Affects Rate. 2. Strong CS. CS. US. Weak CS. cs. US. Suppression and CS Intensity. 3. Another CS Intensity Effect. 4.

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Factors Influencing Conditioning

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  1. Factors Influencing Conditioning CS and US Intensity, and Attention to the CS Temporal relationship Predictiveness Preparedness Redundancy 1

  2. CS Intensity Affects Rate 2 Strong CS CS US Weak CS cs US

  3. Suppression and CS Intensity 3

  4. Another CS Intensity Effect 4 Overshadowing – the more salient CS wins if two CS are trained in compound Group Stage 1 Test Overshadow Ax  US cr Control ax US CR Note: Undercase letters stand for weak intensity CSs

  5. Because the CS is a benign stimulus it will lose the capacity to command ATTENTION if preexposed Little “x” will eventually produce a robust CR CS Attention and Latent Inhibition 5 Group Phase 1 Phase 2 Test Experimental X,X,X… XUS cr Control ---- XUS CR

  6. The Influence of Intensity • Exception: The effect of the CS on the intensity of the CR is sometimes seen when the subject is exposed to both the high and the low intensity CSs which are individually paired with the US on separate trials.

  7. US Intensity Affects Rate and Asymptote 7 Strong US CS US Weak US CS us

  8. Suppression and US Intensity 8

  9. Weaker conditioned responding Temporal Relationship 9 CS Delay US Trace CS US Simultaneous CS US Explicitly Unpaired CS US

  10. Time Conditioning • No distinctive CS • UCS is presented at regular intervals • The passage of time is CS • To determine whether conditioning has occurred, the UCS is omitted and the strength of the CR is assessed

  11. Indirect Conditioning 11 • Many stimuli develop the ability to elicit a CR “indirectly” • i.e., a stimulus that is never itself paired with a UCS comes to elicit the CR • Two important ways for this to happen are • Higher-order conditioning • Sensory preconditioning

  12. Higher-Order Conditioning 12 Group Stage 1 Stage 2 Test Result HOC AUS BA B? cr Control CUS BA B? ziltch HOC: A modest CR develops to B because if signals a “reminder” for the US, namely, the already conditioned A.

  13. Sensory Preconditioning 13 Group Stage 1 Stage 2 Test Result SPC BAAUSB? cr Control BA CUSB? ziltch SPC: A modest CR occurs to B at test, because it signals the A, which is now a “reminder” for the US.

  14. CS-US Preparedness 14 From Garcia & Koelling, 1966 Back

  15. Are forward pairings enough to generate a CR? No!!!!!!!! Predictiveness of the CS 15

  16. Predictiveness of the CS • Predictiveness: the consistency with which the CS is experienced with the UCS, which influences the strength of conditioning. • The pairing of a CS and UCS does not automatically ensure that conditioning will occur.

  17. A Contingency Experiment 17 CS US Chance of US per CS = 2/4 = .5 Chance of US outside CS = 0/10 = 0 Positively Correlated

  18. A Contingency Experiment 18 CS US Chance of US per CS = 2/4 = .5 Chance of US outside CS = 5/10 = .5 Uncorrelated

  19. A Contingency Experiment 2/4 = .5 19 CS US Chance of US per CS = 0/4 = .0 Chance of US outside CS = 5/10 = .5 Negatively Correlated

  20. It’s a little like… Animals are scientists, trying to make cause->effect predictions. …trying to determine whether the US is contingent on the CS …lots of pairings in the zero contingency group 20

  21. Quantifying 21 p(US|CS) = proportion of CS trials with a US p(US|no CS) = proportion of “background” only trials with a US Dp = p(US|CS) - p(US|no CS)

  22. Some Examples p(US|CS) p(US|no CS) 22 Dp • 1.0 • .65 • 0 • -.25 • -1.0 1 2 3 4 5 0/60 = 0 6/60 = .10 30/60 = .5 45/60 = .75 60/60 = 1.0 20/20 = 1.0 15/20 = .75 10/20 = .50 10/20 = .50 0/20 = 0

  23. 1 1.0 Positive 2 -.25 P(US/ CS) 3 4 -1.0 +1.0 +.65 Negative 5 0 1.0 P(US/no CS)

  24. Redundancy 24 Group Stage 1 Stage 2 Test Result Blocking AUS ABUS B? cr Control ABUS B? CR Blocking: Limited or no acquisition of a CR to a second conditioned stimulus, B, when it is introduced alongside an already conditioned first conditioned stimulus , A.

  25. Extinction Paradigm • Extinction of a conditioned response: when the conditioned stimulus does not elicit the conditioned response because the unconditioned stimulus no longer follows the conditioned stimulus

  26. Loss of the CRs • Hull considered the extinction process to be a mirror image of the acquisition. • It is not.One reason for faster extinction than acquisition is that extinction alters the motivation level via omission of the UCS. • Decline is also caused by the development of inhibition rather than erasing the first-learned CS-US association. • So, the CS is part “excitatory” and part “inhibitory” after the end of the last extinction trial

  27. Evidence for new learning • A rest period after the last extinction trial can producespontaneous recovery. More rest causes more spontaneous recovery. • If extinction takes place in a different context than acquisition, a return to the original context of acquisition causes the immediate return of the CR (called ABArenewal).

  28. Duration of CS Exposure • As the duration of CS-alone exposure increases, the strength of the CR weakens • Shipley found total duration of CS alone exposure, not number of extinction trials is critical, but subsequent research has not always confirmed his result.

  29. Exposure Therapy 29 To increase sustained abstinence, some therapists have used a technique that involves exposing the addict to as many drug related cues as possible during extinction. Withdrawal responses and drug cravings decrease as a result of exposure to drug-related cues.

  30. Systematic Desensitization 30 Developed by Joseph Wolpe Used to inhibit fear and suppress phobic behavior SD uses counterconditioning and Wolpe based it on three lines of evidence

  31. Systematic desensitization 31 • Involves performing deep muscle relaxation techniques while first imagining, and then experiencing, anxiety-inducing scenes • Relaxation involves cue-controlled relaxation, a conditioned relaxation response that enables a word cue (e.g., “calm”) to elicit relaxation promptly

  32. Stages 32 • Systematic desensitization consists of four separate stages: • 1) construction of the anxiety hierarchy • 2) relaxation training • 3) counterconditioning – the pairing of relaxation with the feared stimulus and exposure therapy • 4) assessment of whether the patient can successfully interact with the phobic object

  33. Hierarchies 33 • Hierarchies may be either • Thematic: scenes all related to a basic theme • Spatial-temporal: based on phobic behavior in which the intensity of the fear is determined by distance – either physical or temporal

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