TY  - GEN
A1  - Garbusow, Maria
A1  - Nebe, Stephan
A1  - Sommer, Christian
A1  - Kuitunen-Paul, Sören
A1  - Sebold, Miriam
A1  - Schad, Daniel
A1  - Friedel, Eva
A1  - Veer, Ilya M.
A1  - Wittchen, Hans-Ulrich
A1  - Rapp, Michael A.
A1  - Ripke, Stephan
A1  - Walter, Henrik
A1  - Huys, Quentin J. M.
A1  - Schlagenhauf, Florian
A1  - Smolka, Michael N.
A1  - Heinz, Andreas
T1  - Pavlovian-To-Instrumental Transfer and Alcohol Consumption in Young Male Social Drinkers
BT  - Behavioral, Neural and Polygenic Correlates
T2  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - In animals and humans, behavior can be influenced by irrelevant stimuli, a phenomenon called Pavlovian-to-instrumental transfer (PIT). In subjects with substance use disorder, PIT is even enhanced with functional activation in the nucleus accumbens (NAcc) and amygdala. While we observed enhanced behavioral and neural PIT effects in alcohol-dependent subjects, we here aimed to determine whether behavioral PIT is enhanced in young men with high-risk compared to low-risk drinking and subsequently related functional activation in an a-priori region of interest encompassing the NAcc and amygdala and related to polygenic risk for alcohol consumption. A representative sample of 18-year old men (n = 1937) was contacted: 445 were screened, 209 assessed: resulting in 191 valid behavioral, 139 imaging and 157 genetic datasets. None of the subjects fulfilled criteria for alcohol dependence according to the Diagnostic and Statistical Manual of Mental Disorders-IV-TextRevision (DSM-IV-TR). We measured how instrumental responding for rewards was influenced by background Pavlovian conditioned stimuli predicting action-independent rewards and losses. Behavioral PIT was enhanced in high-compared to low-risk drinkers (b = 0.09, SE = 0.03, z = 2.7, p < 0.009). Across all subjects, we observed PIT-related neural blood oxygen level-dependent (BOLD) signal in the right amygdala (t = 3.25, p(SVC) = 0.04, x = 26, y = -6, z = -12), but not in NAcc. The strength of the behavioral PIT effect was positively correlated with polygenic risk for alcohol consumption (r(s) = 0.17, p = 0.032). We conclude that behavioral PIT and polygenic risk for alcohol consumption might be a biomarker for a subclinical phenotype of risky alcohol consumption, even if no drug-related stimulus is present. The association between behavioral PIT effects and the amygdala might point to habitual processes related to out PIT task. In non-dependent young social drinkers, the amygdala rather than the NAcc is activated during PIT; possible different involvement in association with disease trajectory should be investigated in future studies.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 841 
KW  - Pavlovian-to-instrumental transfer
KW  - amygdala
KW  - alcohol
KW  - polygenic risk
KW  - high risk drinkers
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-473280
SN  - 1866-8364
IS  - 841
ER  - 
TY  - JOUR
A1  - Garbusow, Maria
A1  - Nebe, Stephan
A1  - Sommer, Christian
A1  - Kuitunen-Paul, Sören
A1  - Sebold, Miriam
A1  - Schad, Daniel
A1  - Friedel, Eva
A1  - Veer, Ilya M.
A1  - Wittchen, Hans-Ulrich
A1  - Rapp, Michael A.
A1  - Ripke, Stephan
A1  - Walter, Henrik
A1  - Huys, Quentin J. M.
A1  - Schlagenhauf, Florian
A1  - Smolka, Michael N.
A1  - Heinz, Andreas
T1  - Pavlovian-To-Instrumental Transfer and Alcohol Consumption in Young Male Social Drinkers
BT  - Behavioral, Neural and Polygenic Correlates
JF  - Journal of Clinical Medicine
N2  - In animals and humans, behavior can be influenced by irrelevant stimuli, a phenomenon called Pavlovian-to-instrumental transfer (PIT). In subjects with substance use disorder, PIT is even enhanced with functional activation in the nucleus accumbens (NAcc) and amygdala. While we observed enhanced behavioral and neural PIT effects in alcohol-dependent subjects, we here aimed to determine whether behavioral PIT is enhanced in young men with high-risk compared to low-risk drinking and subsequently related functional activation in an a-priori region of interest encompassing the NAcc and amygdala and related to polygenic risk for alcohol consumption. A representative sample of 18-year old men (n = 1937) was contacted: 445 were screened, 209 assessed: resulting in 191 valid behavioral, 139 imaging and 157 genetic datasets. None of the subjects fulfilled criteria for alcohol dependence according to the Diagnostic and Statistical Manual of Mental Disorders-IV-TextRevision (DSM-IV-TR). We measured how instrumental responding for rewards was influenced by background Pavlovian conditioned stimuli predicting action-independent rewards and losses. Behavioral PIT was enhanced in high-compared to low-risk drinkers (b = 0.09, SE = 0.03, z = 2.7, p < 0.009). Across all subjects, we observed PIT-related neural blood oxygen level-dependent (BOLD) signal in the right amygdala (t = 3.25, p(SVC) = 0.04, x = 26, y = -6, z = -12), but not in NAcc. The strength of the behavioral PIT effect was positively correlated with polygenic risk for alcohol consumption (r(s) = 0.17, p = 0.032). We conclude that behavioral PIT and polygenic risk for alcohol consumption might be a biomarker for a subclinical phenotype of risky alcohol consumption, even if no drug-related stimulus is present. The association between behavioral PIT effects and the amygdala might point to habitual processes related to out PIT task. In non-dependent young social drinkers, the amygdala rather than the NAcc is activated during PIT; possible different involvement in association with disease trajectory should be investigated in future studies.
KW  - Pavlovian-to-instrumental transfer
KW  - amygdala
KW  - alcohol
KW  - polygenic risk
KW  - high risk drinkers
Y1  - 2019
U6  - https://doi.org/10.3390/jcm8081188
SN  - 2077-0383
VL  - 8
IS  - 8
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Hoffmann, Mathias
A1  - Wirth, Stephan J.
A1  - Bessler, Holger
A1  - Engels, Christof
A1  - Jochheim, Hubert
A1  - Sommer, Michael
A1  - Augustin, Jürgen
T1  - Combining a root exclusion technique with continuous chamber and porous tube measurements for a pin-point separation of ecosystem respiration in croplands
JF  - Journal of plant nutrition and soil science = Zeitschrift für Pflanzenernährung und Bodenkunde
N2  - To better assess ecosystem C budgets of croplands and understand their potential response to climate and management changes, detailed information on the mechanisms and environmental controls driving the individual C flux components are needed. This accounts in particular for the ecosystem respiration (R-eco) and its components, the autotrophic (R-a) and heterotrophic respiration (R-h) which vary tremendously in time and space. This study presents a method to separate R-eco into R-a [as the sum of R-a (shoot) and R-a (root)] and R-h in order to detect temporal and small-scale spatial dynamics within their relative contribution to overall R-eco. Thus, predominant environmental drivers and underlying mechanisms can be revealed. R-eco was derived during nighttime by automatic chamber CO2 flux measurements on plant covered plots. R-h was derived from CO2 efflux measurements, which were performed in parallel to R-eco measurements on a fallow plot using CO2 sampling tubes in 10 cm soil depth. R-a (root) was calculated as the difference between sampling tube CO2 efflux measurements on a plant covered plot and R-h. R-a (shoot) was calculated as R-eco - R-a (root) - R-h. Measurements were carried out for winter wheat (Triticum aestivum L.) during the crop season 2015 at an experimental plot located in the hummocky ground moraine landscape of NE Germany. R-eco varied seasonally from < 1 to 9.5 g C m(-2) d(-1), and was higher in adult (a) and reproductive (r) than juvenile (j) stands (gC m(-2) d(-1): j = 1.2, a = 4.6, r = 5.3). Observed R-a and R-h were in general smaller compared to the independently measured R-eco, contributing in average 58% and 42% to R-eco. However, both varied strongly regarding their environmental drivers and particular contribution throughout the study period, following the seasonal development of soil temperature and moisture (R-h) as well as crop development (R-a). Thus, our results consistently revealed temporal dynamics regarding the relative contribution of R-a (root) and R-a (shoot) to R-a, as well as of R-a and R-h to R-eco. Based on the observed results, implications for partitioning of R-eco in croplands are given.
KW  - automatic chambers
KW  - autotrophic respiration
KW  - heterotrophic respiration
KW  - soil CO2 sampling tubes
Y1  - 2017
U6  - https://doi.org/10.1002/jpln.201600489
SN  - 1436-8730
SN  - 1522-2624
VL  - 181
IS  - 1
SP  - 41
EP  - 50
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Obst, Elisabeth
A1  - Schad, Daniel
A1  - Huys, Quentin J. M.
A1  - Sebold, Miriam
A1  - Nebe, Stephan
A1  - Sommer, Christian
A1  - Smolka, Michael N.
A1  - Zimmermann, Ulrich S.
T1  - Drunk decisions
BT  - Alcohol shifts choice from habitual towards goal-directed control in adolescent intermediate-risk drinkers
JF  - Journal of Psychopharmacology
N2  - Background: Studies in humans and animals suggest a shift from goal-directed to habitual decision-making in addiction. We therefore tested whether acute alcohol administration reduces goal-directed and promotes habitual decision-making, and whether these effects are moderated by self-reported drinking problems. Methods: Fifty-three socially drinking males completed the two-step task in a randomised crossover design while receiving an intravenous infusion of ethanol (blood alcohol level=80 mg%), or placebo. To minimise potential bias by long-standing heavy drinking and subsequent neuropsychological impairment, we tested 18- to 19-year-old adolescents. Results: Alcohol administration consistently reduced habitual, model-free decisions, while its effects on goal-directed, model-based behaviour varied as a function of drinking problems measured with the Alcohol Use Disorders Identification Test. While adolescents with low risk for drinking problems (scoring <8) exhibited an alcohol-induced numerical reduction in goal-directed choices, intermediate-risk drinkers showed a shift away from habitual towards goal-directed decision-making, such that alcohol possibly even improved their performance. Conclusions: We assume that alcohol disrupted basic cognitive functions underlying habitual and goal-directed decisions in low-risk drinkers, thereby enhancing hasty choices. Further, we speculate that intermediate-risk drinkers benefited from alcohol as a negative reinforcer that reduced unpleasant emotional states, possibly displaying a novel risk factor for drinking in adolescence.
KW  - Computer-assisted Alcohol Infusion System
KW  - habitual learning
KW  - model-free and model-based decision-making
KW  - two-stage Markov decision task
KW  - subjective response to ethanol
KW  - drinking problems
KW  - real-life drinking behaviour
Y1  - 2018
U6  - https://doi.org/10.1177/0269881118772454
SN  - 0269-8811
SN  - 1461-7285
VL  - 32
IS  - 8
SP  - 855
EP  - 866
PB  - Sage Publ.
CY  - London
ER  - 
TY  - JOUR
A1  - Schad, Daniel
A1  - Garbusow, Maria
A1  - Friedel, Eva
A1  - Sommer, Christian
A1  - Sebold, Miriam
A1  - Hägele, Claudia
A1  - Bernhardt, Nadine
A1  - Nebe, Stephan
A1  - Kuitunen-Paul, Sören
A1  - Liu, Shuyan
A1  - Eichmann, Uta
A1  - Beck, Anne
A1  - Wittchen, Hans-Ulrich
A1  - Walter, Henrik
A1  - Sterzer, Philipp
A1  - Zimmermann, Ulrich S.
A1  - Smolka, Michael N.
A1  - Schlagenhauf, Florian
A1  - Huys, Quentin J. M.
A1  - Heinz, Andreas
A1  - Rapp, Michael A.
T1  - Neural correlates of instrumental responding in the context of alcohol-related cues index disorder severity and relapse risk
JF  - European archives of psychiatry and clinical neuroscience : official organ of the German Society for Biological Psychiatry
N2  - The influence of Pavlovian conditioned stimuli on ongoing behavior may contribute to explaining how alcohol cues stimulate drug seeking and intake. Using a Pavlovian-instrumental transfer task, we investigated the effects of alcohol-related cues on approach behavior (i.e., instrumental response behavior) and its neural correlates, and related both to the relapse after detoxification in alcohol-dependent patients. Thirty-one recently detoxified alcohol-dependent patients and 24 healthy controls underwent instrumental training, where approach or non-approach towards initially neutral stimuli was reinforced by monetary incentives. Approach behavior was tested during extinction with either alcohol-related or neutral stimuli (as Pavlovian cues) presented in the background during functional magnetic resonance imaging (fMRI). Patients were subsequently followed up for 6 months. We observed that alcohol-related background stimuli inhibited the approach behavior in detoxified alcohol-dependent patients (t = -3.86, p < .001), but not in healthy controls (t = -0.92, p = .36). This behavioral inhibition was associated with neural activation in the nucleus accumbens (NAcc) (t((30)) = 2.06, p < .05). Interestingly, both the effects were only present in subsequent abstainers, but not relapsers and in those with mild but not severe dependence. Our data show that alcohol-related cues can acquire inhibitory behavioral features typical of aversive stimuli despite being accompanied by a stronger NAcc activation, suggesting salience attribution. The fact that these findings are restricted to abstinence and milder illness suggests that they may be potential resilience factors.
KW  - Alcohol dependence
KW  - Human neuroimaging
KW  - Nucleus accumbens
KW  - Pavlovian-instrumental transfer
KW  - Relapse
Y1  - 2018
U6  - https://doi.org/10.1007/s00406-017-0860-4
SN  - 0940-1334
SN  - 1433-8491
VL  - 269
IS  - 3
SP  - 295
EP  - 308
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - GEN
A1  - Garbusow, Maria
A1  - Sommer, Christian
A1  - Nebe, Stephan
A1  - Sebold, Miriam
A1  - Kuitunen-Paul, Sören
A1  - Wittchen, Hans-Ulrich
A1  - Smolka, Michael N.
A1  - Zimmermann, Ulrich S.
A1  - Rapp, Michael A.
A1  - Huys, Quentin J. M.
A1  - Schlagenhauf, Florian
A1  - Heinz, Andreas
T1  - Multi-level evidence of general pavlovian-to-instrumental transfer in alcohol use disorder
T2  - Alcoholism : clinical and experimental research ; the official journal of the American Medical Society on Alcoholism and the Research Society on Alcoholism
Y1  - 2018
SN  - 0145-6008
SN  - 1530-0277
VL  - 42
SP  - 128A
EP  - 128A
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - GEN
A1  - Sebold, Miriam
A1  - Nebe, Stephan
A1  - Garbusow, Maria
A1  - Schad, Daniel
A1  - Sommer, Christian
A1  - Rapp, Michael A.
A1  - Smolka, Michael N.
A1  - Huys, Quentin J. M.
A1  - Schlagenhauf, Florian
A1  - Heinz, Andreas
T1  - Neurobiological correlates of learning and decision-making in alcohol dependence
T2  - European psychiatry : the journal of the Association of European Psychiatrists
Y1  - 2017
U6  - https://doi.org/10.1016/j.eurpsy.2017.01.084
SN  - 0924-9338
SN  - 1778-3585
VL  - 41
SP  - S11
EP  - S11
PB  - Elsevier
CY  - Paris
ER  - 
TY  - INPR
A1  - Singhal, Puja
A1  - Pahle, Michael
A1  - Kalkuhl, Matthias
A1  - Sommer, Stephan
A1  - Levesque, Antoine
A1  - Berneiser, Jessica
T1  - Beyond good faith
BT  - why evidence-based policy is necessary to decarbonize buildings cost-effectively
T2  - SSRN eLibrary / Social Science Research Network
N2  - The ambitious climate targets set by industrialized nations worldwide cannot be met without decarbonizing the building stock. Using Germany as a case study, this paper takes stock of the extensive set of energy efficiency policies that are already in place and clarifies that they have been designed “in good faith” but lack in overall effectiveness as well as cost-efficiency in achieving these climate targets. We map out the market failures and behavioural considerations that are potential reasons for why realized energy savings fall below expectations and why the household adoption of energy-efficient and low-carbon technologies has remained low. We highlight the pressing need for data and modern empirical research to develop targeted and cost-effective policies seeking to correct these market failures. To this end, we identify some key research questions and identify gaps in the data required for evidence-based policy.
KW  - energy efficiency
KW  - decarbonization
KW  - housing sector
KW  - heat demand
KW  - evidence-based policy
Y1  - 2021
U6  - https://doi.org/10.2139/ssrn.3947800
SN  - 1556-5068
PB  - SSRN - Elsevier
CY  - Rochester, NY
ER  - 
TY  - JOUR
A1  - Sebold, Miriam
A1  - Nebe, Stephan
A1  - Garbusow, Maria
A1  - Guggenmos, Matthias
A1  - Schad, Daniel
A1  - Beck, Anne
A1  - Kuitunen-Paul, Sören
A1  - Sommer, Christian
A1  - Frank, Robin
A1  - Neu, Peter
A1  - Zimmermann, Ulrich S.
A1  - Rapp, Michael A.
A1  - Smolka, Michael N.
A1  - Huys, Quentin J. M.
A1  - Schlagenhauf, Florian
A1  - Heinz, Andreas
T1  - When Habits Are Dangerous: Alcohol Expectancies and Habitual Decision Making Predict Relapse in Alcohol Dependence
JF  - Biological psychiatry : a journal of psychiatric neuroscience and therapeutics ; a publication of the Society of Biological Psychiatry
N2  - 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.
KW  - Alcohol dependence
KW  - Alcohol expectancy
KW  - Goal-directed control
KW  - Medial prefrontal cortex
KW  - Reinforcement learning
KW  - Treatment outcome
Y1  - 2017
U6  - https://doi.org/10.1016/j.biopsych.2017.04.019
SN  - 0006-3223
SN  - 1873-2402
VL  - 82
SP  - 847
EP  - 856
PB  - Elsevier
CY  - New York
ER  - 
TY  - JOUR
A1  - Garbusow, Maria
A1  - Schad, Daniel
A1  - Sebold, Miriam
A1  - Friedel, Eva
A1  - Bernhardt, Nadine
A1  - Koch, Stefan P.
A1  - Steinacher, Bruno
A1  - Kathmann, Norbert
A1  - Geurts, Dirk E. M.
A1  - Sommer, Christian
A1  - Mueller, Dirk K.
A1  - Nebe, Stephan
A1  - Paul, Soeren
A1  - Wittchen, Hans-Ulrich
A1  - Zimmermann, Ulrich S.
A1  - Walter, Henrik
A1  - Smolka, Michael N.
A1  - Sterzer, Philipp
A1  - Rapp, Michael A.
A1  - Huys, Quentin J. M.
A1  - Schlagenhauf, Florian
A1  - Heinz, Andreas
T1  - Pavlovian-to-instrumental transfer effects in the nucleus accumbens relate to relapse in alcohol dependence
JF  - Addiction biology
N2  - 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.
KW  - human Pavlovian-to-instrumental transfer
KW  - nucleus accumbens
KW  - relapse in alcohol use disorder
Y1  - 2016
U6  - https://doi.org/10.1111/adb.12243
SN  - 1355-6215
SN  - 1369-1600
VL  - 21
SP  - 719
EP  - 731
PB  - Wiley-Blackwell
CY  - Hoboken
ER  -