An experimental study on spontaneous recovery of conditioned reward expectancies and instrumental responding in humans

The effects of a retrieval cue on renewal of conditioned responses in human appetitive conditioning

Contextual renewal of reward anticipation may be one potential mechanism underlying relapse in eating and substance use disorders. We therefore tested retrieval cues, a method derived from an inhibitory retrieval-based model of extinction learning to attenuate contextual renewal using an appetitive conditioning paradigm. A pilot study was carried out in Experiment 1 to validate a differential chocolate conditioning paradigm, in which a specific tray was set up as a conditioned stimulus (CS) for eating chocolate (unconditioned stimulus, US). Using an ABA renewal design in Experiment 2, half of the participants were presented with a retrieval cue in the acquisition phase (group AC) and the other half in the extinction phase (group EC). Presentation of the retrieval cue in the EC was associated with reduced renewal of US-expectancy, while there was a clear renewal effect for US-expectancy in the AC. One limitation was the difference in cue presentations between both groups due to the number of trials in acquisition and extinction. Experiment 3 therefore aimed at replicating the results of Experiment 2, but with fewer cue presentations for the EC to match the AC. No significant group differences were observed indicating no effect of the retrieval cue. Theoretical and clinical implications in light of the differing results are discussed.

Recovery-from-extinction effects in an anuran amphibian: renewal effect, but no reinstatement

Recovery-from-extinction effects in which a conditioned response returns after extinction have been shown in mammals, birds and fish. Thus, these effects appear to be conserved among vertebrates; however, they have yet to be investigated in amphibians. Using prey catching conditioning in the fire-bellied toad (Bombina orientalis), we tested if renewal and reinstatement occurred after extinction when subjects were respectively re-exposed to the context or reinforcer used during conditioning. For renewal, a different context was used during extinction and thus renewal tests assessed if external contextual cues associated during conditioning stimulated prey catching performance. For reinstatement, the reinforcer withheld during extinction was simply delivered again prior to a test assessing if internal cues associated with recent prey consumption stimulated prey catching performance. Conditioning followed a fixed ratio 5 schedule of reinforcement, where five attempts to capture a cricket stimulus displayed on a computer screen were reinforced by delivery of a single live cricket. Performance was measured as the time to reach five prey catching attempts. A significant improvement in prey catching performance during conditioning followed by deterioration with extinction was seen in the experiments. Upon return to the context used for conditioning after extinction, toads showed a renewal effect whereby they displayed faster performance during testing compared to the end of extinction. Conversely, toads showed no reinstatement effect because pre-feeding of a cricket did not influence performance during the test that followed extinction. Reinstatement could have been lost in amphibian phylogeny due to secondary simplification of the nervous system.

Feedback-Related Brain Potentials Indicate the Influence of Craving on Decision-Making in Patients with Alcohol Use Disorder: An Experimental Study

INTRODUCTION

Alcohol craving is a key symptom of alcohol use disorder (AUD) and a significant cause of poor treatment outcome and frequent relapse. Craving is supposed to impair executive functions by modulating reward salience and decision-making.

OBJECTIVE

The present study sought to clarify this modulation by scrutinizing reward feedback processing in an experimental decision-making task, which was accomplished by AUD patients in 2 conditions, in the context of induced alcohol craving and in neutral context.

METHODS

AUD inpatients (N = 40) accomplished the Balloon Analog Risk Task, while their EEG was monitored; counterbalanced across conditions, the tasks were preceded either by craving induction by means of imagery and olfactory alcohol cues, or by neutral cues. Decision choice and variability, and event-related potentials (ERPs) prior to (stimulus-preceding negativity [SPN]) and following (P2a) reward feedback upon decisions, and the outcome-related feedback-related negativity (FRN) were compared between conditions and between patients, who experienced high craving upon alcohol cues (N = 18) and those who did not (N = 22).

RESULTS

Upon craving induction (vs. neutral condition), high-craving AUD patients showed less adjustment of decision choice to preceding reward experience and more variable decisions than low-craving AUD patients, together with accentuated reward-associated ERP (SPN and P2a), while outcome-related FRN was not modified by craving.

CONCLUSIONS

Results support orientation to reward in AUD patients, particularly amplified upon experienced craving, which may interfere with (feedback-guided) decision-making even in alcohol-unrelated context. Craving-accentuated ERP indices suggest neuroadaptive changes of cognitive-motivational states upon chronic alcohol abuse. Together with altered reward-related expectancies, this has to be considered in intervention and relapse prevention.