TY  - JOUR
A1  - Sebold, Miriam
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 A.
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  - Heinzel, Stephan
A1  - Lorenz, Robert C.
A1  - Quynh-Lam Duong, 
A1  - Rapp, Michael A.
A1  - Deserno, Lorenz
T1  - Prefrontal-parietal effective connectivity during working memory in older adults
JF  - Neurobiology of Aging
N2  - Theoretical models and preceding studies have described age-related alterations in neuronal activation of frontoparietal regions in a working memory (WM)load-dependent manner. However, to date, underlying neuronal mechanisms of these WM load-dependent activation changes in aging remain poorly understood. The aim of this study was to investigate these mechanisms in terms of effective connectivity by application of dynamic causal modeling with Bayesian Model Selection. Eighteen healthy younger (age: 20-32 years) and 32 older (60-75 years) participants performed an n-back task with 3 WM load levels during functional magnetic resonance imaging (fMRI). Behavioral and conventional fMRI results replicated age group by WM load interactions. Importantly, the analysis of effective connectivity derived from dynamic causal modeling, indicated an age-and performance-related reduction in WM load-dependent modulation of connectivity from dorsolateral prefrontal cortex to inferior parietal lobule. This finding provides evidence for the proposal that age-related WM decline manifests as deficient WM load-dependent modulation of neuronal top-down control and can integrate implications from theoretical models and previous studies of functional changes in the aging brain.
KW  - Aging
KW  - Dynamic causal modeling (DCM)
KW  - Effective connectivity
KW  - Functional magnetic resonance imaging (fMRI)
KW  - Working memory
Y1  - 2017
U6  - https://doi.org/10.1016/j.neurobiolaging.2017.05.005
SN  - 0197-4580
SN  - 1558-1497
VL  - 57
SP  - 18
EP  - 27
PB  - Elsevier
CY  - New York
ER  -