Extinction of cue-evoked drug-seeking relies on degrading hierarchical instrumental expectancies.
Bottom Line: 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.
Affiliation: School of Psychology, University of Exeter, Washington Singer Building, Perry Road, Exeter EX4 4QG, UK; School of Psychology, University of New South Wales, Sydney, NSW 2052, Australia. Electronic address: email@example.com.Show MeSH
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Mentions: In the discriminative extinction training stage, half of participants underwent extinction while the other half did not (Table 2). The purpose of discriminative extinction training was to establish a beer stimulus (two glass jugs of beer being clashed together) as a signal that the beer response (R1) from concurrent training session 1 would now not produce beer points (points were used rather than quarters of reinforcers to align the design with the seminal study of Gámez and Rosas (2005) which used game points). Concurrent training proceeded as before for 48 trials except in a randomly selected half of trials, the beer stimulus (S1) was presented alongside the prompt ‘UP or DOWN?’, and pressing the beer key unexpectedly produced the outcome ‘Nothing’ alongside a large red cross stimulus to highlight non-reward. By contrast, pressing the chocolate response (R2) in the beer stimulus continued to produce the outcome ‘One chocolate point’ accompanied by a picture of a Cadbury Dairy Milk chocolate bar 230 g, as before. In the randomly interleaved ‘no stimulus’ trials (S2), both R1 and R2 continued to produce their outcomes as in concurrent training stage 1. Thus, the beer stimulus was scheduled as a unique signal that the beer response would not produce beer. By contrast, in the non-extinguished group, both R1 and R2 continued to be reinforced as before, in both the beer stimulus and no stimulus trials. The dependent measure was the percentage choice of the beer (R1) versus the chocolate (R2) response. It was expected that the extinguished group would learn to withhold the beer response in the beer stimulus, whereas the non-extinguished group would preferentially perform the beer response in the beer stimulus (Fig. 3A).
Affiliation: School of Psychology, University of Exeter, Washington Singer Building, Perry Road, Exeter EX4 4QG, UK; School of Psychology, University of New South Wales, Sydney, NSW 2052, Australia. Electronic address: firstname.lastname@example.org.