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Factors Influencing Conditioning 1 CS and US Intensity, and Attention to the CS Temporal relationship Predictiveness Preparedness Redundancy CS Intensity Affects Rate 2 Strong CS CS US Weak CS cs US Suppression and CS Intensity 3 Another CS Intensity Effect 4 Overshadowing – the more salient CS wins if two CS are trained in compound Group Overshadow Control Stage 1 Ax US ax US Note: Undercase letters stand for weak intensity CSs Test cr CR CS Attention and Latent Inhibition 5 Group Phase 1 Experimental X,X,X… Control --- Phase 2 XUS XUS Test cr CR 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 The Influence of Intensity 6 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. US Intensity Affects Rate and Asymptote 7 Strong US CS US Weak US CS us Suppression and US Intensity 8 Temporal Relationship Weaker conditioned responding 9 CS Delay US Trace CS US Simultaneous CS US Explicitly Unpaired CS US Time Conditioning 10 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 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 Higher-Order Conditioning 12 Group HOC Control Stage 1 AUS CUS Stage 2 BA BA Test B? B? Result cr ziltch HOC: A modest CR develops to B because if signals a “reminder” for the US, namely, the already conditioned A. Sensory Preconditioning 13 Group SPC Control Stage 1 BA BA Stage 2 AUS CUS Test B? B? Result cr ziltch SPC: A modest CR occurs to B at test, because it signals the A, which is now a “reminder” for the US. CS-US Preparedness 14 From Garcia & Koelling, 1966 Back Predictiveness of the CS 15 Are forward pairings enough to generate a CR? No!!!!!!!! Predictiveness of the CS 16 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. A Contingency Experiment 17 CS US Chance of US per CS = 2/4 = .5 Chance of US outside CS = 0/10 = 0 Positively Correlated A Contingency Experiment 18 CS US Chance of US per CS = 2/4 = .5 Chance of US outside CS = 5/10 = .5 Uncorrelated A Contingency Experiment 19 CS US Chance of US per CS = 0/4 2/4 = .0 .5 Chance of US outside CS = 5/10 = .5 Negatively Correlated It’s a little like… 20 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 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) Some Examples 22 p(US|CS) p(US|no CS) Dp 20/20 = 1.0 0/60 = 0 • 1.0 1 15/20 = .75 6/60 = .10 • .65 2 10/20 = .50 30/60 = .5 • 0 3 10/20 = .50 45/60 = .75 • -.25 4 0/20 = 0 60/60 = 1.0 • -1.0 5 1.0 1 Positive P(US/ CS) 2 +1.0 +.65 -.25 3 4 -1.0 Negative 0 P(US/no CS) 5 1.0 Redundancy 24 Group Blocking Control Stage 1 AUS Stage 2 ABUS ABUS Test B? B? Result cr 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. Extinction Paradigm 25 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 Loss of the CRs 26 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 Evidence for new learning 27 A rest period after the last extinction trial can produce spontaneous 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 ABA renewal). Duration of CS Exposure 28 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. 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. 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 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 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 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