TY  - JOUR
A1  - Sebold, Miriam
A1  - Schad, Daniel
A1  - Nebe, Stephan
A1  - Garbusow, Maria
A1  - Juenger, Elisabeth
A1  - Kroemer, Nils B.
A1  - Kathmann, Norbert
A1  - Zimmermann, Ulrich S.
A1  - Smolka, Michael N.
A1  - Rapp, Michael A.
A1  - Heinz, Andreas
A1  - Huys, Quentin J. M.
T1  - Pavlovian-to-Instrumental Transfer Effects Rely Less on Model-based Reinforcement Learning
JF  - Journal of cognitive neuroscience
N2  - Behavioral choice can be characterized along two axes. One axis distinguishes reflexive, model-free systems that slowly accumulate values through experience and a model-based system that uses knowledge to reason prospectively. The second axis distinguishes Pavlovian valuation of stimuli from instrumental valuation of actions or stimulus–action pairs. This results in four values and many possible interactions between them, with important consequences for accounts of individual variation. We here explored whether individual variation along one axis was related to individual variation along the other. Specifically, we asked whether individuals' balance between model-based and model-free learning was related to their tendency to show Pavlovian interferences with instrumental decisions. In two independent samples with a total of 243 participants, Pavlovian–instrumental transfer effects were negatively correlated with the strength of model-based reasoning in a two-step task. This suggests a potential common underlying substrate predisposing individuals to both have strong Pavlovian interference and be less model-based and provides a framework within which to interpret the observation of both effects in addiction.
Y1  - 2016
U6  - https://doi.org/10.1162/jocn_a_00945
SN  - 0898-929X
SN  - 1530-8898
VL  - 28
SP  - 985
EP  - 995
PB  - MIT Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Nebe, Stephan
A1  - Kroemer, Nils B.
A1  - Schad, Daniel
A1  - Bernhardt, Nadine
A1  - Sebold, Miriam
A1  - Mueller, Dirk K.
A1  - Scholl, Lucie
A1  - Kuitunen-Paul, Sören
A1  - Heinz, Andreas
A1  - Rapp, Michael A.
A1  - Huys, Quentin J. M.
A1  - Smolka, Michael N.
T1  - No association of goal-directed and habitual control with alcohol consumption in young adults
JF  - Addiction biology
N2  - 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.
KW  - alcohol
KW  - goal-directed
KW  - reinforcement learning
Y1  - 2017
U6  - https://doi.org/10.1111/adb.12490
SN  - 1355-6215
SN  - 1369-1600
VL  - 23
IS  - 1
SP  - 379
EP  - 393
PB  - Wiley
CY  - Hoboken
ER  -