TY - JOUR A1 - Sebold, Miriam Hannah A1 - Deserno, Lorenz A1 - Nebe, Stefan A1 - Schad, Daniel A1 - Garbusow, Maria A1 - Haegele, Claudia A1 - Keller, Juergen A1 - Juenger, Elisabeth A1 - Kathmann, Norbert A1 - Smolka, Michael N. A1 - Rapp, Michael Armin A1 - Schlagenhauf, Florian A1 - Heinz, Andreas A1 - Huys, Quentin J. M. T1 - Model-based and model-free decisions in alcohol dependence JF - Neuropsychobiology : international journal of experimental and clinical research in biological psychiatry, pharmacopsychiatry, Biological Psychology/Pharmacopsychology and Pharmacoelectroencephalography N2 - Background: Human and animal work suggests a shift from goal-directed to habitual decision-making in addiction. However, the evidence for this in human alcohol dependence is as yet inconclusive. Methods: Twenty-six healthy controls and 26 recently detoxified alcohol-dependent patients underwent behavioral testing with a 2-step task designed to disentangle goal-directed and habitual response patterns. Results: Alcohol-dependent patients showed less evidence of goal-directed choices than healthy controls, particularly after losses. There was no difference in the strength of the habitual component. The group differences did not survive controlling for performance on the Digit Symbol Substitution Task. Conclusion: Chronic alcohol use appears to selectively impair goal-directed function, rather than promoting habitual responding. It appears to do so particularly after nonrewards, and this may be mediated by the effects of alcohol on more general cognitive functions subserved by the prefrontal cortex. KW - Alcohol dependence KW - Decision-making KW - Reinforcement learning KW - Dopamine KW - Computational psychiatry Y1 - 2014 U6 - https://doi.org/10.1159/000362840 SN - 0302-282X SN - 1423-0224 VL - 70 IS - 2 SP - 122 EP - 131 PB - Karger CY - Basel ER - TY - JOUR A1 - Sebold, Miriam Hannah A1 - Garbusow, Maria A1 - Jetzschmann, P. A1 - Schad, Daniel A1 - Nebe, S. A1 - Schlagenhauf, Florian A1 - Heinz, A. A1 - Rapp, Michael Armin A1 - Romanczuk-Seiferth, Nina T1 - Reward and avoidance learning in the context of aversive environments and possible implications for depressive symptoms JF - Psychopharmacology N2 - Background Aversive stimuli in the environment influence human actions. This includes valence-dependent influences on action selection, e.g., increased avoidance but decreased approach behavior. However, it is yet unclear how aversive stimuli interact with complex learning and decision-making in the reward and avoidance domain. Moreover, the underlying computational mechanisms of these decision-making biases are unknown. Methods To elucidate these mechanisms, 54 healthy young male subjects performed a two-step sequential decision-making task, which allows to computationally model different aspects of learning, e.g., model-free, habitual, and model-based, goal-directed learning. We used a within-subject design, crossing task valence (reward vs. punishment learning) with emotional context (aversive vs. neutral background stimuli). We analyzed choice data, applied a computational model, and performed simulations. Results Whereas model-based learning was not affected, aversive stimuli interacted with model-free learning in a way that depended on task valence. Thus, aversive stimuli increased model-free avoidance learning but decreased model-free reward learning. The computational model confirmed this effect: the parameter lambda that indicates the influence of reward prediction errors on decision values was increased in the punishment condition but decreased in the reward condition when aversive stimuli were present. Further, by using the inferred computational parameters to simulate choice data, our effects were captured. Exploratory analyses revealed that the observed biases were associated with subclinical depressive symptoms. Conclusion Our data show that aversive environmental stimuli affect complex learning and decision-making, which depends on task valence. Further, we provide a model of the underlying computations of this affective modulation. Finally, our finding of increased decision-making biases in subjects reporting subclinical depressive symptoms matches recent reports of amplified Pavlovian influences on action selection in depression and suggests a potential vulnerability factor for mood disorders. We discuss our findings in the light of the involvement of the neuromodulators serotonin and dopamine. KW - Reward learning KW - Avoidance learning KW - Reinforcement learning KW - Computational psychiatry KW - Decision-making KW - Affective modulation KW - Depression symptoms Y1 - 2019 U6 - https://doi.org/10.1007/s00213-019-05299-9 SN - 0033-3158 SN - 1432-2072 VL - 236 IS - 8 SP - 2437 EP - 2449 PB - Springer CY - New York ER -