@article{FriedelSeboldKuitunenPauletal.2017, author = {Friedel, Eva and Sebold, Miriam 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 A. 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 and Mueller, Dirk K. and Scholl, Lucie and Kuitunen-Paul, S{\"o}ren and Heinz, Andreas and Rapp, Michael A. 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} } @article{SeboldNebeGarbusowetal.2017, author = {Sebold, Miriam 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 A. 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{SeboldSchadNebeetal.2016, author = {Sebold, Miriam and Schad, Daniel and Nebe, Stephan and Garbusow, Maria and Juenger, Elisabeth and Kroemer, Nils B. and Kathmann, Norbert and Zimmermann, Ulrich S. and Smolka, Michael N. and Rapp, Michael A. and Heinz, Andreas and Huys, Quentin J. M.}, title = {Pavlovian-to-Instrumental Transfer Effects Rely Less on Model-based Reinforcement Learning}, series = {Journal of cognitive neuroscience}, volume = {28}, journal = {Journal of cognitive neuroscience}, publisher = {MIT Press}, address = {Cambridge}, issn = {0898-929X}, doi = {10.1162/jocn_a_00945}, pages = {985 -- 995}, year = {2016}, abstract = {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.}, language = {en} } @article{GarbusowSchadSeboldetal.2016, author = {Garbusow, Maria and Schad, Daniel and Sebold, Miriam and Friedel, Eva and Bernhardt, Nadine and Koch, Stefan P. and Steinacher, Bruno and Kathmann, Norbert and Geurts, Dirk E. M. and Sommer, Christian and Mueller, Dirk K. and Nebe, Stephan and Paul, Soeren and Wittchen, Hans-Ulrich and Zimmermann, Ulrich S. and Walter, Henrik and Smolka, Michael N. and Sterzer, Philipp and Rapp, Michael A. and Huys, Quentin J. M. and Schlagenhauf, Florian and Heinz, Andreas}, title = {Pavlovian-to-instrumental transfer effects in the nucleus accumbens relate to relapse in alcohol dependence}, series = {Addiction biology}, volume = {21}, journal = {Addiction biology}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1355-6215}, doi = {10.1111/adb.12243}, pages = {719 -- 731}, year = {2016}, abstract = {In detoxified alcohol-dependent patients, alcohol-related stimuli can promote relapse. However, to date, the mechanisms by which contextual stimuli promote relapse have not been elucidated in detail. One hypothesis is that such contextual stimuli directly stimulate the motivation to drink via associated brain regions like the ventral striatum and thus promote alcohol seeking, intake and relapse. Pavlovian-to-Instrumental-Transfer (PIT) may be one of those behavioral phenomena contributing to relapse, capturing how Pavlovian conditioned (contextual) cues determine instrumental behavior (e.g. alcohol seeking and intake). We used a PIT paradigm during functional magnetic resonance imaging to examine the effects of classically conditioned Pavlovian stimuli on instrumental choices in n=31 detoxified patients diagnosed with alcohol dependence and n=24 healthy controls matched for age and gender. Patients were followed up over a period of 3 months. We observed that (1) there was a significant behavioral PIT effect for all participants, which was significantly more pronounced in alcohol-dependent patients; (2) PIT was significantly associated with blood oxygen level-dependent (BOLD) signals in the nucleus accumbens (NAcc) in subsequent relapsers only; and (3) PIT-related NAcc activation was associated with, and predictive of, critical outcomes (amount of alcohol intake and relapse during a 3 months follow-up period) in alcohol-dependent patients. These observations show for the first time that PIT-related BOLD signals, as a measure of the influence of Pavlovian cues on instrumental behavior, predict alcohol intake and relapse in alcohol dependence.}, language = {en} } @article{GarbusowSchadSommeretal.2014, author = {Garbusow, Maria and Schad, Daniel and Sommer, Christian and Juenger, Elisabeth and Sebold, Miriam and Friedel, Eva and Wendt, Jean and Kathmann, Norbert and Schlagenhauf, Florian and Zimmermann, Ulrich S. and Heinz, Andreas and Huys, Quentin J. M. and Rapp, Michael A.}, title = {Pavlovian-to-instrumental transfer in alcohol dependence: a pilot study}, series = {Neuropsychobiology : international journal of experimental and clinical research in biological psychiatry, pharmacopsychiatry, Biological Psychology/Pharmacopsychology and Pharmacoelectroencephalography}, volume = {70}, journal = {Neuropsychobiology : international journal of experimental and clinical research in biological psychiatry, pharmacopsychiatry, Biological Psychology/Pharmacopsychology and Pharmacoelectroencephalography}, number = {2}, publisher = {Karger}, address = {Basel}, issn = {0302-282X}, doi = {10.1159/000363507}, pages = {111 -- 121}, year = {2014}, abstract = {Background: Pavlovian processes are thought to play an important role in the development, maintenance and relapse of alcohol dependence, possibly by influencing and usurping ongoing thought and behavior. The influence of pavlovian stimuli on ongoing behavior is paradigmatically measured by pavlovian-to-instrumental transfer (PIT) tasks. These involve multiple stages and are complex. Whether increased PIT is involved in human alcohol dependence is uncertain. We therefore aimed to establish and validate a modified PIT paradigm that would be robust, consistent and tolerated by healthy controls as well as by patients suffering from alcohol dependence, and to explore whether alcohol dependence is associated with enhanced PIT. Methods: Thirty-two recently detoxified alcohol-dependent patients and 32 age- and gender-matched healthy controls performed a PIT task with instrumental go/no-go approach behaviors. The task involved both pavlovian stimuli associated with monetary rewards and losses, and images of drinks. Results: Both patients and healthy controls showed a robust and temporally stable PIT effect. Strengths of PIT effects to drug-related and monetary conditioned stimuli were highly correlated. Patients more frequently showed a PIT effect, and the effect was stronger in response to aversively conditioned CSs (conditioned suppression), but there was no group difference in response to appetitive CSs. Conclusion: The implementation of PIT has favorably robust properties in chronic alcohol-dependent patients and in healthy controls. It shows internal consistency between monetary and drug-related cues. The findings support an association of alcohol dependence with an increased propensity towards PIT.}, language = {en} } @article{SeboldDesernoNebeetal.2014, author = {Sebold, Miriam and Deserno, Lorenz and Nebe, Stefan and Schad, Daniel and Garbusow, Maria and Haegele, Claudia and Keller, Juergen and Juenger, Elisabeth and Kathmann, Norbert and Smolka, Michael N. and Rapp, Michael A. and Schlagenhauf, Florian and Heinz, Andreas and Huys, Quentin J. M.}, title = {Model-based and model-free decisions in alcohol dependence}, series = {Neuropsychobiology : international journal of experimental and clinical research in biological psychiatry, pharmacopsychiatry, Biological Psychology/Pharmacopsychology and Pharmacoelectroencephalography}, volume = {70}, journal = {Neuropsychobiology : international journal of experimental and clinical research in biological psychiatry, pharmacopsychiatry, Biological Psychology/Pharmacopsychology and Pharmacoelectroencephalography}, number = {2}, publisher = {Karger}, address = {Basel}, issn = {0302-282X}, doi = {10.1159/000362840}, pages = {122 -- 131}, year = {2014}, abstract = {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.}, language = {en} } @article{SchadJuengerSeboldetal.2014, author = {Schad, Daniel and Juenger, Elisabeth and Sebold, Miriam and Garbusow, Maria and Bernhardt, Nadine and Javadi, Amir-Homayoun and Zimmermann, Ulrich S. and Smolka, Michael N. and Heinz, Andreas and Rapp, Michael A. and Huys, Quentin J. M.}, title = {Processing speed enhances model-based over model-free reinforcement learning in the presence of high working memory functioning}, series = {Frontiers in psychology}, volume = {5}, journal = {Frontiers in psychology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-1078}, doi = {10.3389/fpsyg.2014.01450}, pages = {10}, year = {2014}, abstract = {Theories of decision-making and its neural substrates have long assumed the existence of two distinct and competing valuation systems, variously described as goal-directed vs. habitual, or, more recently and based on statistical arguments, as model-free vs. model-based reinforcement-learning. Though both have been shown to control choices, the cognitive abilities associated with these systems are under ongoing investigation. Here we examine the link to cognitive abilities, and find that individual differences in processing speed covary with a shift from model-free to model-based choice control in the presence of above-average working memory function. This suggests shared cognitive and neural processes; provides a bridge between literatures on intelligence and valuation; and may guide the development of process models of different valuation components. Furthermore, it provides a rationale for individual differences in the tendency to deploy valuation systems, which may be important for understanding the manifold neuropsychiatric diseases associated with malfunctions of valuation.}, language = {en} }