@article{FriedelSchlagenhaufBecketal.2015,
  author    = {Friedel, Eva and Schlagenhauf, Florian and Beck, Anne and Dolan, Raymond J. and Huys, Quentin J. M. and Rapp, Michael A. and Heinz, Andreas},
  title     = {The effects of life stress and neural learning signals on fluid intelligence},
  series = {European archives of psychiatry and clinical neuroscience : official organ of the German Society for Biological Psychiatry},
  volume    = {265},
  journal   = {European archives of psychiatry and clinical neuroscience : official organ of the German Society for Biological Psychiatry},
  number    = {1},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0940-1334},
  doi       = {10.1007/s00406-014-0519-3},
  pages     = {35 -- 43},
  year      = {2015},
  abstract  = {Fluid intelligence (fluid IQ), defined as the capacity for rapid problem solving and behavioral adaptation, is known to be modulated by learning and experience. Both stressful life events (SLES) and neural correlates of learning [specifically, a key mediator of adaptive learning in the brain, namely the ventral striatal representation of prediction errors (PE)] have been shown to be associated with individual differences in fluid IQ. Here, we examine the interaction between adaptive learning signals (using a well-characterized probabilistic reversal learning task in combination with fMRI) and SLES on fluid IQ measures. We find that the correlation between ventral striatal BOLD PE and fluid IQ, which we have previously reported, is quantitatively modulated by the amount of reported SLES. Thus, after experiencing adversity, basic neuronal learning signatures appear to align more closely with a general measure of flexible learning (fluid IQ), a finding complementing studies on the effects of acute stress on learning. The results suggest that an understanding of the neurobiological correlates of trait variables like fluid IQ needs to take socioemotional influences such as chronic stress into account.},
  language  = {en}
}
@article{BaltaBeylergilBeckDesernoetal.2017,
  author    = {Balta Beylergil, Sinem and Beck, Anne and Deserno, Lorenz and Lorenz, Robert C. and Rapp, Michael A. and Schlagenhauf, Florian and Heinz, Andreas and Obermayer, Klaus},
  title     = {Dorsolateral prefrontal cortex contributes to the impaired behavioral adaptation in alcohol dependence},
  series = {NeuroImage: Clinical : a journal of diseases affecting the nervous system},
  volume    = {15},
  journal   = {NeuroImage: Clinical : a journal of diseases affecting the nervous system},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {2213-1582},
  doi       = {10.1016/j.nicl.2017.04.010},
  pages     = {80 -- 94},
  year      = {2017},
  abstract  = {Substance-dependent individuals often lack the ability to adjust decisions flexibly in response to the changes in reward contingencies. Prediction errors (PEs) are thought to mediate flexible decision-making by updating the reward values associated with available actions. In this study, we explored whether the neurobiological correlates of PEs are altered in alcohol dependence. Behavioral, and functional magnetic resonance imaging (fMRI) data were simultaneously acquired from 34 abstinent alcohol-dependent patients (ADP) and 26 healthy controls (HC) during a probabilistic reward-guided decision-making task with dynamically changing reinforcement contingencies. A hierarchical Bayesian inference method was used to fit and compare learning models with different assumptions about the amount of task-related information subjects may have inferred during the experiment. Here, we observed that the best-fitting model was a modified Rescorla-Wagner type model, the "double-update" model, which assumes that subjects infer the knowledge that reward contingencies are anti-correlated, and integrate both actual and hypothetical outcomes into their decisions. Moreover, comparison of the best-fitting model's parameters showed that ADP were less sensitive to punishments compared to HC. Hence, decisions of ADP after punishments were loosely coupled with the expected reward values assigned to them. A correlation analysis between the model-generated PEs and the fMRI data revealed a reduced association between these PEs and the BOLD activity in the dorsolateral prefrontal cortex (DLPFC) of ADP. A hemispheric asymmetry was observed in the DLPFC when positive and negative PE signals were analyzed separately. The right DLPFC activity in ADP showed a reduced correlation with positive PEs. On the other hand, ADP, particularly the patients with high dependence severity, recruited the left DLPFC to a lesser extent than HC for processing negative PE signals. These results suggest that the DLPFC, which has been linked to adaptive control of action selection, may play an important role in cognitive inflexibility observed in alcohol dependence when reinforcement contingencies change. Particularly, the left DLPFC may contribute to this impaired behavioral adaptation, possibly by impeding the extinction of the actions that no longer lead to a reward.},
  language  = {en}
}