@article{FriedelSeboldKuitunenPauletal.2017, author = {Friedel, Eva and Sebold, Miriam Hannah and Kuitunen-Paul, S{\"o}ren and Nebe, Stephan and Veer, Ilya M. and Zimmermann, Ulrich S. and Schlagenhauf, Florian and Smolka, Michael N. and Rapp, Michael Armin and Walter, Henrik and Heinz, Andreas}, title = {How Accumulated Real Life Stress Experience and Cognitive Speed Interact on Decision-Making Processes}, series = {Frontiers in human neuroscienc}, volume = {11}, journal = {Frontiers in human neuroscienc}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1662-5161}, doi = {10.3389/fnhum.2017.00302}, pages = {1 -- 9}, year = {2017}, abstract = {Rationale: Advances in neurocomputational modeling suggest that valuation systems for goal-directed (deliberative) on one side, and habitual (automatic) decision-making on the other side may rely on distinct computational strategies for reinforcement learning, namely model-free vs. model-based learning. As a key theoretical difference, the model-based system strongly demands cognitive functions to plan actions prospectively based on an internal cognitive model of the environment, whereas valuation in the model-free system relies on rather simple learning rules from operant conditioning to retrospectively associate actions with their outcomes and is thus cognitively less demanding. Acute stress reactivity is known to impair model-based but not model-free choice behavior, with higher working memory capacity protecting the model-based system from acute stress. However, it is not clear which impact accumulated real life stress has on model-free and model-based decision systems and how this influence interacts with cognitive abilities. Methods: We used a sequential decision-making task distinguishing relative contributions of both learning strategies to choice behavior, the Social Readjustment Rating Scale questionnaire to assess accumulated real life stress, and the Digit Symbol Substitution Test to test cognitive speed in 95 healthy subjects. Results: Individuals reporting high stress exposure who had low cognitive speed showed reduced model-based but increased model-free behavioral control. In contrast, subjects exposed to accumulated real life stress with high cognitive speed displayed increased model-based performance but reduced model-free control. Conclusion: These findings suggest that accumulated real life stress exposure can enhance reliance on cognitive speed for model-based computations, which may ultimately protect the model-based system from the detrimental influences of accumulated real life stress. The combination of accumulated real life stress exposure and slower information processing capacities, however, might favor model-free strategies. Thus, the valence and preference of either system strongly depends on stressful experiences and individual cognitive capacities.}, language = {en} } @article{NebeKroemerSchadetal.2017, author = {Nebe, Stephan and Kroemer, Nils B. and Schad, Daniel and Bernhardt, Nadine and Sebold, Miriam Hannah and Mueller, Dirk K. and Scholl, Lucie and Kuitunen-Paul, S{\"o}ren and Heinz, Andreas and Rapp, Michael Armin and Huys, Quentin J. M. and Smolka, Michael N.}, title = {No association of goal-directed and habitual control with alcohol consumption in young adults}, series = {Addiction biology}, volume = {23}, journal = {Addiction biology}, number = {1}, publisher = {Wiley}, address = {Hoboken}, issn = {1355-6215}, doi = {10.1111/adb.12490}, pages = {379 -- 393}, year = {2017}, 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.}, language = {en} } @misc{SeboldNebeGarbusowetal.2017, author = {Sebold, Miriam Hannah and Nebe, Stephan and Garbusow, Maria and Schad, Daniel and Sommer, Christian and Rapp, Michael Armin and Smolka, Michael N. and Huys, Quentin J. M. and Schlagenhauf, Florian and Heinz, Andreas}, title = {Neurobiological correlates of learning and decision-making in alcohol dependence}, series = {European psychiatry : the journal of the Association of European Psychiatrists}, volume = {41}, journal = {European psychiatry : the journal of the Association of European Psychiatrists}, publisher = {Elsevier}, address = {Paris}, issn = {0924-9338}, doi = {10.1016/j.eurpsy.2017.01.084}, pages = {S11 -- S11}, year = {2017}, language = {en} } @article{SeboldNebeGarbusowetal.2017, author = {Sebold, Miriam Hannah and Nebe, Stephan and Garbusow, Maria and Guggenmos, Matthias and Schad, Daniel and Beck, Anne and Kuitunen-Paul, S{\"o}ren and Sommer, Christian and Frank, Robin and Neu, Peter and Zimmermann, Ulrich S. and Rapp, Michael Armin and Smolka, Michael N. and Huys, Quentin J. M. and Schlagenhauf, Florian and Heinz, Andreas}, title = {When Habits Are Dangerous: Alcohol Expectancies and Habitual Decision Making Predict Relapse in Alcohol Dependence}, series = {Biological psychiatry : a journal of psychiatric neuroscience and therapeutics ; a publication of the Society of Biological Psychiatry}, volume = {82}, journal = {Biological psychiatry : a journal of psychiatric neuroscience and therapeutics ; a publication of the Society of Biological Psychiatry}, publisher = {Elsevier}, address = {New York}, issn = {0006-3223}, doi = {10.1016/j.biopsych.2017.04.019}, pages = {847 -- 856}, year = {2017}, abstract = {BACKGROUND: Addiction is supposedly characterized by a shift from goal-directed to habitual decision making, thus facilitating automatic drug intake. The two-step task allows distinguishing between these mechanisms by computationally modeling goal-directed and habitual behavior as model-based and model-free control. In addicted patients, decision making may also strongly depend upon drug-associated expectations. Therefore, we investigated model-based versus model-free decision making and its neural correlates as well as alcohol expectancies in alcohol-dependent patients and healthy controls and assessed treatment outcome in patients. METHODS: Ninety detoxified, medication-free, alcohol-dependent patients and 96 age-and gender-matched control subjects underwent functional magnetic resonance imaging during the two-step task. Alcohol expectancies were measured with the Alcohol Expectancy Questionnaire. Over a follow-up period of 48 weeks, 37 patients remained abstinent and 53 patients relapsed as indicated by the Alcohol Timeline Followback method. RESULTS: Patients who relapsed displayed reduced medial prefrontal cortex activation during model-based decision making. Furthermore, high alcohol expectancies were associated with low model-based control in relapsers, while the opposite was observed in abstainers and healthy control subjects. However, reduced model-based control per se was not associated with subsequent relapse. CONCLUSIONS: These findings suggest that poor treatment outcome in alcohol dependence does not simply result from a shift from model-based to model-free control but is instead dependent on the interaction between high drug expectancies and low model-based decision making. Reduced model-based medial prefrontal cortex signatures in those who relapse point to a neural correlate of relapse risk. These observations suggest that therapeutic interventions should target subjective alcohol expectancies.}, language = {en} } @article{SommerGarbusowJuengeretal.2017, author = {Sommer, C. and Garbusow, Maria and Juenger, E. and Pooseh, S. and Bernhardt, Nadine and Birkenstock, J. and Schad, Daniel and Jabs, B. and Gloeckler, T. and Huys, Quentin J. M. and Heinz, A. and Smolka, Michael N. and Zimmermann, Ulrich S.}, title = {Strong seduction: impulsivity and the impact of contextual cues on instrumental behavior in alcohol dependence}, series = {Translational Psychiatry}, volume = {7}, journal = {Translational Psychiatry}, publisher = {Nature Publ. Group}, address = {New York}, issn = {2158-3188}, doi = {10.1038/tp.2017.158}, pages = {1209 -- 1222}, year = {2017}, abstract = {Alcohol-related cues acquire incentive salience through Pavlovian conditioning and then can markedly affect instrumental behavior of alcohol-dependent patients to promote relapse. However, it is unclear whether similar effects occur with alcohol-unrelated cues. We tested 116 early-abstinent alcohol-dependent patients and 91 healthy controls who completed a delay discounting task to assess choice impulsivity, and a Pavlovian-to-instrumental transfer (PIT) paradigm employing both alcohol-unrelated and alcohol-related stimuli. To modify instrumental choice behavior, we tiled the background of the computer screen either with conditioned stimuli (CS) previously generated by pairing abstract pictures with pictures indicating monetary gains or losses, or with pictures displaying alcohol or water beverages. CS paired to money gains and losses affected instrumental choices differently. This PIT effect was significantly more pronounced in patients compared to controls, and the group difference was mainly driven by highly impulsive patients. The PIT effect was particularly strong in trials in which the instrumental stimulus required inhibition of instrumental response behavior and the background CS was associated to monetary gains. Under that condition, patients performed inappropriate approach behavior, contrary to their previously formed behavioral intention. Surprisingly, the effect of alcohol and water pictures as background stimuli resembled that of aversive and appetitive CS, respectively. These findings suggest that positively valenced background CS can provoke dysfunctional instrumental approach behavior in impulsive alcohol-dependent patients. Consequently, in real life they might be easily seduced by environmental cues to engage in actions thwarting their long-term goals. Such behaviors may include, but are not limited to, approaching alcohol.}, language = {en} }