@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}
}
@article{GarbusowSchadSeboldetal.2016,
  author    = {Garbusow, Maria and Schad, Daniel and Sebold, Miriam Hannah 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 Armin 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}
}