Compound Stimulus Presentation Does Not Deepen Extinction in Human Causal Learning.

Oren Griffiths,Nathan Holmes,R Fred Westbrook

doi:10.3389/fpsyg.2017.00120

Abstract

Models of associative learning have proposed that cue-outcome learning critically depends on the degree of prediction error encountered during training. Two experiments examined the role of error-driven extinction learning in a human causal learning task. Target cues underwent extinction in the presence of additional cues, which differed in the degree to which they predicted the outcome, thereby manipulating outcome expectancy and, in the absence of any change in reinforcement, prediction error. These prediction error manipulations have each been shown to modulate extinction learning in aversive conditioning studies. While both manipulations resulted in increased prediction error during training, neither enhanced extinction in the present human learning task (one manipulation resulted in less extinction at test). The results are discussed with reference to the types of associations that are regulated by prediction error, the types of error terms involved in their regulation, and how these interact with parameters involved in training.

Highlights

Prediction error refers to the degree of mismatch between what is expected to occur, and what occurs
The compound of two allergenic cues (CD−) elicited higher outcome predictions at the beginning of Phase 3, indicating that people initially expected the outcome more on these trials than on the initial AB− trials of Phase 3. This demonstrates that the manipulation was effective and that prediction error was greater across the CD− than the AB− trials; more associative change should have accrued to C and D than to B
In contrast to the results reported by Lovibond et al (2000), Vervliet et al (2007), and Culver et al (2015) found enhanced extinction for cues trained in compound over cues trained in isolation

Summary

Introduction

Prediction error refers to the degree of mismatch between what is expected to occur, and what occurs. The cue is repeatedly presented in the absence of the outcome, referred to as A− trials On each of these trials, the expectation of the outcome (+) elicited by the presence of the cue (A) is violated by the experimenter withholding that outcome After several errors in prediction (or prediction errors) whereby the outcome is anticipated but fails to occur, subjects learn that the cue no longer signals the outcome, and responses to the cue cease. At this point the cue-outcome association is said to be extinguished. Any procedure that purports to enhance extinction learning offers the prospect of enhancing the efficacy of its real-world applications, such as exposure therapy

Results

Discussion

Conclusion