Extinction of cue-evoked drug-seeking relies on degrading hierarchical instrumental expectancies

Lee Hogarth,Chris Retzler,Marcus R Munafò,Dominic M.D Tran,Joseph R Troisi,Abigail K Rose,Andrew Jones,Matt Field

doi:10.1016/j.brat.2014.06.001

Abstract

There has long been need for a behavioural intervention that attenuates cue-evoked drug-seeking, but the optimal method remains obscure. To address this, we report three approaches to extinguish cue-evoked drug-seeking measured in a Pavlovian to instrumental transfer design, in non-treatment seeking adult smokers and alcohol drinkers. The results showed that the ability of a drug stimulus to transfer control over a separately trained drug-seeking response was not affected by the stimulus undergoing Pavlovian extinction training in experiment 1, but was abolished by the stimulus undergoing discriminative extinction training in experiment 2, and was abolished by explicit verbal instructions stating that the stimulus did not signal a more effective response-drug contingency in experiment 3. These data suggest that cue-evoked drug-seeking is mediated by a propositional hierarchical instrumental expectancy that the drug-seeking response is more likely to be rewarded in that stimulus. Methods which degraded this hierarchical expectancy were effective in the laboratory, and so may have therapeutic potential.

Highlights

Experiment 2 was based on a study by Gamez and Rosas (2005, experiment 2) which abolished the Pavlovian to instrumental transfer (PIT) effect with non-drug cues using a discriminative extinction procedure
The results showed that the ability of a drug stimulus to transfer control over a separately trained drug-seeking response was not affected by the stimulus undergoing Pavlovian extinction training in experiment 1, but was abolished by the stimulus undergoing discriminative extinction training in experiment 2, and was abolished by explicit verbal instructions stating that the stimulus did not signal a more effective response-drug contingency in experiment 3
Experiment 1 tested whether a Pavlovian extinction procedure (Hogarth & Chase, 2012) would abolish the PIT effect produced by drug cues (Hogarth et al, 2007)

Summary

Introduction

Experiment 2 was based on a study by Gamez and Rosas (2005, experiment 2) which abolished the PIT effect with non-drug cues using a discriminative extinction procedure. Recall that Gamez & Rosas (2005) trained an arbitrary stimulus to signal that one R-O contingency was in force S:R1-O1, and in discriminative extinction switched this stimulus to signal that the R would no longer produce its' outcome S:R1-no O1. Another second response was trained with the same outcome (R3-O1), before the extinguished S was tested for the ability to prime selection of that new response in a PIT test, S:R3-. It is expected that discriminate extinction training will abolish the PIT

Methods

Results

Conclusion