Citation

Nebe S, Kroemer NB, Schad DJ, Bernhardt N, Sebold M, Müller DK, Scholl L, Kuitunen-Paul S, Heinz A, Rapp MA, Huys QJ, Smolka MN. Addict. Biol. 2018; 23(1): 379-393.

Affiliation

Neuroimaging Center, Technische Universität Dresden, Germany.

Copyright

(Copyright © 2018, John Wiley and Sons)

DOI

10.1111/adb.12490

PMID

28111829

Abstract

Alcohol dependence is a mental disorder that has been associated with an imbalance in behavioral control favoring model-free habitual over model-based goal-directed strategies. It is as yet unknown, however, whether such an imbalance reflects a predisposing vulnerability or results as a consequence of repeated and/or excessive alcohol exposure. We, therefore, examined the association of alcohol consumption with model-based goal-directed and model-free habitual control in 188 18-year-old social drinkers in a two-step sequential decision-making task while undergoing functional magnetic resonance imaging before prolonged alcohol misuse could have led to severe neurobiological adaptations. Behaviorally, participants showed a mixture of model-free and model-based decision-making as observed previously. Measures of impulsivity were positively related to alcohol consumption. In contrast, neither model-free nor model-based decision weights nor the trade-off between them were associated with alcohol consumption. There were also no significant associations between alcohol consumption and neural correlates of model-free or model-based decision quantities in either ventral striatum or ventromedial prefrontal cortex. Exploratory whole-brain functional magnetic resonance imaging analyses with a lenient threshold revealed early onset of drinking to be associated with an enhanced representation of model-free reward prediction errors in the posterior putamen. These results suggest that an imbalance between model-based goal-directed and model-free habitual control might rather not be a trait marker of alcohol intake per se.

© 2017 Society for the Study of Addiction.

Language: en

Keywords

alcohol; goal-directed; reinforcement learning