Whatever Happened to Behavior, Anyway?
“Forgetting” Context & Extinction Whatever Happened to Behavior, Anyway? W. J. Wilson, Psychology March 16, 2015 Occasion Setting “Forgetting” Context & Extinction Occasion Setting How Long is Learning Retained? 0.7 160 1 day 60 days 140 0.6 Suppression Index 120 Licks 100 80 60 40 0.5 0.4 0.3 0.2 0.1 20 0 B BX 0 0.5 1 Intensity of the US (mA) 2 0 1 1 Day 2 35 Days • Hendersen (1985): CS+ effect seems not to fade • Hendersen (1978): CI effect seems to fade “Forgetting” Context & Extinction Occasion Setting Causes of “Forgetting” • Trace decay? • Interference? • Retrieval failure (context)? Suppression ratio 0.5 Ext-A Ext-B NE 0.4 0.3 0.2 0.1 0 1 2 3 4 5 6 7 8 9 10 Two-trial blocks 1 2 3 4 “Forgetting” Context & Extinction Occasion Setting Context and Extinction US CS Context • Renewal effect • Spontaneous recovery? • Rapid reacquisition? • Relapse after therapy for phobia? • Latent inhibition? “Forgetting” Context & Extinction Occasion Setting Occasion Setting • One stimulus can indicate whether or not another stimulus will be followed by the US. • L→ T+ TFeature-positive discrimination • L→ TT+ Feature-negative discrimination • Rescorla-Wagner model predicts different learning than does occasion setting. “Forgetting” Context & Extinction Occasion Setting Occasion Setting “Forgetting” Context & Extinction Occasion Setting Occasion Setting “Forgetting” Context & Extinction Occasion Setting Occasion Setting • L→ T+ T- Head Jerk • T- Rearing LT+ • How do L and T differ in the two procedures (besides timing)? “Forgetting” Context & Extinction Occasion Setting Occasion Setting • SALIENCE! • Less salient stimulus will serve as occasion setter for more salient stimulus. • If equally salient. “Rescorla-Wagner rules” apply. “Forgetting” Context & Extinction Occasion Setting Stimulus Substitution • Pavlov: CS comes to substitute for the US (e.g., dog thinks of bell as food). • This led to the erroneous conclusion that CR will be small version of UR. • Siegel’s compensatory CRs contradict stimulus substitution. • Timberlake & Grant. . .
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