TY - JOUR A1 - Nettels, Daniel A1 - Müller-Späth, Sonja A1 - Küster, Frank A1 - Hofmann, Hagen A1 - Haenni, Domminik A1 - Rüegger, Stefan A1 - Reymond, Luc A1 - Hoffmann, Armin S. A1 - Kubelka, Jan A1 - Heinz, Benjamin A1 - Gast, Klaus A1 - Best, Robert B. A1 - Schuler, Benjamin T1 - Single-molecule spectroscopy of the temperature-induced collapse of unfolded proteins N2 - We used single-molecule FRET in combination with other biophysical methods and molecular simulations to investigate the effect of temperature on the dimensions of unfolded proteins. With singlemolecule FRET, this question can be addressed even under nearnative conditions, where most molecules are folded, allowing us to probe a wide range of denaturant concentrations and temperatures. We find a compaction of the unfolded state of a small cold shock protein with increasing temperature in both the presence and the absence of denaturant, with good agreement between the results from single-molecule FRET and dynamic light scattering. Although dissociation of denaturant from the polypeptide chain with increasing temperature accounts for part of the compaction, the results indicate an important role for additional temperaturedependent interactions within the unfolded chain. The observation of a collapse of a similar extent in the extremely hydrophilic, intrinsically disordered protein prothymosin suggests that the hydrophobic effect is not the sole source of the underlying interactions. Circular dichroism spectroscopy and replica exchange molecular dynamics simulations in explicit water show changes in secondary structure content with increasing temperature and suggest a contribution of intramolecular hydrogen bonding to unfolded state collapse. Y1 - 2009 UR - http://www.pnas.org/content/106/49/20740.full.pdf+html SN - 0027-8424 ER - TY - CHAP A1 - Völler, Heinz A1 - Salzwedel, Annett A1 - Reibis, Rona Katharina A1 - Kaminski, S. A1 - Buhlert, Hermann A1 - Eichler, Sarah A1 - Wegscheider, Karl T1 - Age and fitness level are strongest limitations of exercise capacity during inpatient cardiac rehabilitation T2 - European heart journal Y1 - 2014 SN - 0195-668X SN - 1522-9645 VL - 35 SP - 899 EP - 899 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Heinz, S. A1 - Jung, I. A1 - Stegmann, Christian T1 - Systematic studies of the Richardson-Lucy deconvolution algorithm applied to VHE gamma data JF - ASTROPARTICLE PHYSICS N2 - The Richardson-Lucy deconvolution algorithm was applied to astronomical images in the very high-energy regime with photon energies above 100 GeV. Through a systematic study with respect to source significance, background level and source morphology we were able to derive optimal deconvolution parameters. The results presented show that deconvolution makes it possible to study structural details well below the angular resolution of the very high-energy gamma-ray experiment. (C) 2012 Elsevier B.V. All rights reserved. KW - Very high energy gamma-ray astronomy KW - Deconvolution Y1 - 2012 U6 - https://doi.org/10.1016/j.astropartphys.2012.05.013 SN - 0927-6505 VL - 36 IS - 1 SP - 146 EP - 150 PB - ELSEVIER SCIENCE BV CY - AMSTERDAM ER - TY - JOUR A1 - Hansen, Dominique A1 - Dendale, Paul A1 - Coninx, Karin A1 - Vanhees, Luc A1 - Piepoli, Massimo F. A1 - Niebauer, Josef A1 - Cornelissen, Veronique A1 - Pedretti, Roberto A1 - Geurts, Eva A1 - Ruiz, Gustavo R. A1 - Corra, Ugo A1 - Schmid, Jean-Paul A1 - Greco, Eugenio A1 - Davos, Constantinos H. A1 - Edelmann, Frank A1 - Abreu, Ana A1 - Rauch, Bernhard A1 - Ambrosetti, Marco A1 - Braga, Simona S. A1 - Barna, Olga A1 - Beckers, Paul A1 - Bussotti, Maurizio A1 - Fagard, Robert A1 - Faggiano, Pompilio A1 - Garcia-Porrero, Esteban A1 - Kouidi, Evangelia A1 - Lamotte, Michel A1 - Neunhaeuserer, Daniel A1 - Reibis, Rona Katharina A1 - Spruit, Martijn A. A1 - Stettler, Christoph A1 - Takken, Tim A1 - Tonoli, Cajsa A1 - Vigorito, Carlo A1 - Völler, Heinz A1 - Doherty, Patrick T1 - The European Association of Preventive Cardiology Exercise Prescription in Everyday Practice and Rehabilitative Training (EXPERT) tool: A digital training and decision support system for optimized exercise prescription in cardiovascular disease. Concept, definitions and construction methodology JF - European journal of preventive cardiology : the official ESC journal for primary & secondary cardiovascular prevention, rehabilitation and sports cardiology N2 - Background Exercise rehabilitation is highly recommended by current guidelines on prevention of cardiovascular disease, but its implementation is still poor. Many clinicians experience difficulties in prescribing exercise in the presence of different concomitant cardiovascular diseases and risk factors within the same patient. It was aimed to develop a digital training and decision support system for exercise prescription in cardiovascular disease patients in clinical practice: the European Association of Preventive Cardiology Exercise Prescription in Everyday Practice and Rehabilitative Training (EXPERT) tool. Methods EXPERT working group members were requested to define (a) diagnostic criteria for specific cardiovascular diseases, cardiovascular disease risk factors, and other chronic non-cardiovascular conditions, (b) primary goals of exercise intervention, (c) disease-specific prescription of exercise training (intensity, frequency, volume, type, session and programme duration), and (d) exercise training safety advices. The impact of exercise tolerance, common cardiovascular medications and adverse events during exercise testing were further taken into account for optimized exercise prescription. Results Exercise training recommendations and safety advices were formulated for 10 cardiovascular diseases, five cardiovascular disease risk factors (type 1 and 2 diabetes, obesity, hypertension, hypercholesterolaemia), and three common chronic non-cardiovascular conditions (lung and renal failure and sarcopaenia), but also accounted for baseline exercise tolerance, common cardiovascular medications and occurrence of adverse events during exercise testing. An algorithm, supported by an interactive tool, was constructed based on these data. This training and decision support system automatically provides an exercise prescription according to the variables provided. Conclusion This digital training and decision support system may contribute in overcoming barriers in exercise implementation in common cardiovascular diseases. KW - Cardiovascular disease KW - rehabilitation KW - exercise training KW - training and decision support system Y1 - 2017 U6 - https://doi.org/10.1177/2047487317702042 SN - 2047-4873 SN - 2047-4881 VL - 24 SP - 1017 EP - 1031 PB - Sage Publ. CY - London ER - TY - JOUR A1 - Stracke, A. A1 - Bayer, A. A1 - Zimmermann, S. A1 - Wendorff, Joachim Heinz A1 - Wirges, Werner A1 - Bauer-Gogonea, Simona A1 - Bauer, Siegfried A1 - Gerhard, Reimund T1 - Relaxation behaviour of electrically induced polar orientation and of optically induced non-polar orientation in an azo-chromophore side group polymer Y1 - 1999 SN - 0022-3727 ER - TY - JOUR A1 - de Vera, Jean-Pierre Paul A1 - Böttger, Ute A1 - de la Torre Nötzel, Rosa A1 - Sanchez, Francisco J. A1 - Grunow, Dana A1 - Schmitz, Nicole A1 - Lange, Caroline A1 - Hübers, Heinz-Wilhelm A1 - Billi, Daniela A1 - Baque, Mickael A1 - Rettberg, Petra A1 - Rabbow, Elke A1 - Reitz, Günther A1 - Berger, Thomas A1 - Möller, Ralf A1 - Bohmeier, Maria A1 - Horneck, Gerda A1 - Westall, Frances A1 - Jänchen, Jochen A1 - Fritz, Jörg A1 - Meyer, Cornelia A1 - Onofri, Silvano A1 - Selbmann, Laura A1 - Zucconi, Laura A1 - Kozyrovska, Natalia A1 - Leya, Thomas A1 - Foing, Bernard A1 - Demets, Rene A1 - Cockell, Charles S. A1 - Bryce, Casey A1 - Wagner, Dirk A1 - Serrano, Paloma A1 - Edwards, Howell G. M. A1 - Joshi, Jasmin Radha A1 - Huwe, Björn A1 - Ehrenfreund, Pascale A1 - Elsaesser, Andreas A1 - Ott, Sieglinde A1 - Meessen, Joachim A1 - Feyh, Nina A1 - Szewzyk, Ulrich A1 - Jaumann, Ralf A1 - Spohn, Tilman T1 - Supporting Mars exploration BIOMEX in Low Earth Orbit and further astrobiological studies on the Moon using Raman and PanCam technology JF - Planetary and space science N2 - The Low Earth Orbit (LEO) experiment Biology and Mars Experiment (BIOMEX) is an interdisciplinary and international space research project selected by ESA. The experiment will be accommodated on the space exposure facility EXPOSE-R2 on the International Space Station (ISS) and is foreseen to be launched in 2013. The prime objective of BIOMEX is to measure to what extent biomolecules, such as pigments and cellular components, are resistant to and able to maintain their stability under space and Mars-like conditions. The results of BIOMEX will be relevant for space proven biosignature definition and for building a biosignature data base (e.g. the proposed creation of an international Raman library). The library will be highly relevant for future space missions such as the search for life on Mars. The secondary scientific objective is to analyze to what extent terrestrial extremophiles are able to survive in space and to determine which interactions between biological samples and selected minerals (including terrestrial, Moon- and Mars analogs) can be observed under space and Mars-like conditions. In this context, the Moon will be an additional platform for performing similar experiments with negligible magnetic shielding and higher solar and galactic irradiation compared to LEO. Using the Moon as an additional astrobiological exposure platform to complement ongoing astrobiological LEO investigations could thus enhance the chances of detecting organic traces of life on Mars. We present a lunar lander mission with two related objectives: a lunar lander equipped with Raman and PanCam instruments which can analyze the lunar surface and survey an astrobiological exposure platform. This dual use of testing mission technology together with geo- and astrobiological analyses will significantly increase the science return, and support the human preparation objectives. It will provide knowledge about the Moon's surface itself and, in addition, monitor the stability of life-markers, such as cells, cell components and pigments, in an extraterrestrial environment with much closer radiation properties to the surface of Mars. The combination of a Raman data base of these data together with data from LEO and space simulation experiments, will lead to further progress on the analysis and interpretation of data that we will obtain from future Moon and Mars exploration missions. KW - Moon KW - Mars KW - Low Earth Orbit KW - Astrobiology KW - Instrumentation KW - Spectroscopy KW - Biosignature Y1 - 2012 U6 - https://doi.org/10.1016/j.pss.2012.06.010 SN - 0032-0633 VL - 74 IS - 1 SP - 103 EP - 110 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Sianova, D. A1 - Zen, Achmad A1 - Nothofer, Heinz-Georg A1 - Asawapirom, Udom A1 - Scherf, Ullrich A1 - Hagen, R. A1 - Bieringer, Thomas A1 - Kostromine, S. A1 - Neher, Dieter T1 - Photoaddressable alignment layers for fluorescent polymers in polarized electroluminescence devices Y1 - 2002 ER - TY - JOUR A1 - Oda, Masao A1 - Nothofer, Heinz-Georg A1 - Lieser, G. A1 - Scherf, Ullrich A1 - Meskers, S. C. J. A1 - Neher, Dieter T1 - Circularly-polarized electroluminescence from liquid-crystalline chiral polyfluorenes Y1 - 2000 ER - TY - JOUR A1 - Oda, Masao A1 - Meskers, S. C. J. A1 - Nothofer, Heinz-Georg A1 - Scherf, Ullrich A1 - Neher, Dieter T1 - Chiroptical properties of chiral-substituted polyfluorenes Y1 - 2000 ER - TY - GEN A1 - Kuschpel, Maxim S. A1 - Liu, Shuyan A1 - Schad, Daniel A1 - Heinzel, Stephan A1 - Heinz, Andreas A1 - Rapp, Michael A. T1 - Differential effects of wakeful rest, music and video game playing on working memory performance in the n-back task N2 - The interruption of learning processes by breaks filled with diverse activities is common in everyday life. We investigated the effects of active computer gaming and passive relaxation (rest and music) breaks on working memory performance. Young adults were exposed to breaks involving (i) eyes-open resting, (ii) listening to music and (iii) playing the video game “Angry Birds” before performing the n-back working memory task. Based on linear mixed-effects modeling, we found that playing the “Angry Birds” video game during a short learning break led to a decline in task performance over the course of the task as compared to eyes-open resting and listening to music, although overall task performance was not impaired. This effect was associated with high levels of daily mind wandering and low self-reported ability to concentrate. These findings indicate that video games can negatively affect working memory performance over time when played in between learning tasks. We suggest further investigation of these effects because of their relevance to everyday activity. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 280 KW - attention KW - break interventions KW - cognitive resources KW - computer games KW - mind wandering KW - mozart effect KW - working memory Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-85151 ER - TY - GEN A1 - Liu, Shuyan A1 - Schad, Daniel A1 - Kuschpel, Maxim S. A1 - Rapp, Michael A. A1 - Heinz, Andreas T1 - Music and Video Gaming during Breaks BT - Influence on Habitual versus Goal-Directed Decision Making N2 - Different systems for habitual versus goal-directed control are thought to underlie human decision-making. Working memory is known to shape these decision-making systems and their interplay, and is known to support goal-directed decision making even under stress. Here, we investigated if and how decision systems are differentially influenced by breaks filled with diverse everyday life activities known to modulate working memory performance. We used a within-subject design where young adults listened to music and played a video game during breaks interleaved with trials of a sequential two-step Markov decision task, designed to assess habitual as well as goal-directed decision making. Based on a neurocomputational model of task performance, we observed that for individuals with a rather limited working memory capacity video gaming as compared to music reduced reliance on the goal-directed decision-making system, while a rather large working memory capacity prevented such a decline. Our findings suggest differential effects of everyday activities on key decision-making processes. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 289 KW - Cognition KW - Cognitive impairment KW - Decision making KW - Games KW - Learning KW - Music cognition KW - Video games KW - Working memory Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-90700 SP - 1 EP - 12 ER - TY - JOUR A1 - Garbusow, Maria A1 - Schad, Daniel A1 - Sommer, Christian A1 - Juenger, Elisabeth A1 - Sebold, Miriam A1 - Friedel, Eva A1 - Wendt, Jean A1 - Kathmann, Norbert A1 - Schlagenhauf, Florian A1 - Zimmermann, Ulrich S. A1 - Heinz, Andreas A1 - Huys, Quentin J. M. A1 - Rapp, Michael A. T1 - Pavlovian-to-instrumental transfer in alcohol dependence: a pilot study JF - Neuropsychobiology : international journal of experimental and clinical research in biological psychiatry, pharmacopsychiatry, Biological Psychology/Pharmacopsychology and Pharmacoelectroencephalography N2 - 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. KW - Pavlovian-to-instrumental transfer KW - Alcohol dependence KW - Human Y1 - 2014 U6 - https://doi.org/10.1159/000363507 SN - 0302-282X SN - 1423-0224 VL - 70 IS - 2 SP - 111 EP - 121 PB - Karger CY - Basel 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 - JOUR A1 - Sekutowicz, Maria A1 - Guggenmos, Matthias A1 - Kuitunen-Paul, Sören A1 - Garbusow, Maria A1 - Sebold, Miriam A1 - Pelz, Patricia A1 - Priller, Josef A1 - Wittchen, Hans-Ulrich A1 - Smolka, Michael N. A1 - Zimmermann, Ulrich S. A1 - Heinz, Andreas A1 - Sterzer, Philipp A1 - Schmack, Katharina T1 - Neural Response Patterns During Pavlovian-to-Instrumental Transfer Predict Alcohol Relapse and Young Adult Drinking JF - Biological psychiatry : a journal of psychiatric neuroscience and therapeutics ; a publication of the Society of Biological Psychiatry N2 - BACKGROUND: Pavlovian-to-instrumental transfer (PIT) describes the influence of conditioned stimuli on instrumental behaviors and is discussed as a key process underlying substance abuse. Here, we tested whether neural responses during alcohol-related PIT predict future relapse in alcohol-dependent patients and future drinking behavior in adolescents. METHODS: Recently detoxified alcohol-dependent patients (n = 52) and young adults without dependence (n = 136) underwent functional magnetic resonance imaging during an alcohol-related PIT paradigm, and their drinking behavior was assessed in a 12-month follow-up. To predict future drinking behavior from PIT activation patterns, we used a multivoxel classification scheme based on linear support vector machines. RESULTS: When training and testing the classification scheme in patients, PIT activation patterns predicted future relapse with 71.2% accuracy. Feature selection revealed that classification was exclusively based on activation patterns in medial prefrontal cortex. To probe the generalizability of this functional magnetic resonance imaging-based prediction of future drinking behavior, we applied the support vector machine classifier that had been trained on patients to PIT functional magnetic resonance imaging data from adolescents. An analysis of cross-classification predictions revealed that those young social drinkers who were classified as abstainers showed a greater reduction in alcohol consumption at 12-month follow-up than those classified as relapsers (Delta = -24.4 +/- 6.0 g vs. -5.7 +/- 3.6 g; p = .019). CONCLUSIONS: These results suggest that neural responses during PIT could constitute a generalized prognostic marker for future drinking behavior in established alcohol use disorder and in at-risk states. KW - Alcohol dependence KW - Future drinking behavior KW - Multivoxel classification KW - Pavlovian-to-instrumental transfer KW - Relapse Y1 - 2019 U6 - https://doi.org/10.1016/j.biopsych.2019.06.028 SN - 0006-3223 SN - 1873-2402 VL - 86 IS - 11 SP - 857 EP - 863 PB - Elsevier CY - New York ER - TY - GEN A1 - Garbusow, Maria A1 - Sommer, C. A1 - Nebe, S. A1 - Sebold, Miriam A1 - Kuitunen-Paul, Sören A1 - Wittchen, H. U. A1 - Smolka, M. A1 - Zimmermann, U. A1 - Rapp, Michael A. A1 - Huys, Q. A1 - Schlagenhauf, Florian A1 - Heinz, A. T1 - Pavlovian-instrumental transfer in the course of alcohol use disorder T2 - European psychiatry : the journal of the Association of European Psychiatrists N2 - Background: Pavlovian processes are thought to play an important role in the development, maintenance and relapse of alcohol dependence, possibly by influencing and usurping on- going thought and behavior. The influence of Pavlovian stimuli on on-going 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 Pavlovian-Instrumental transfer. Methods: 32 recently detoxified alcohol-dependent patients and 32 age and gender matched healthy controls performed a PIT task with instrumental go/no-go approach behaviours. 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. Y1 - 2018 SN - 0924-9338 SN - 1778-3585 VL - 48 SP - S546 EP - S546 PB - Elsevier CY - ISSY-LES-MOULINEAUX ER - TY - JOUR A1 - Sebold, Miriam A1 - Schad, Daniel A1 - Nebe, Stephan A1 - Garbusow, Maria A1 - Juenger, Elisabeth A1 - Kroemer, Nils B. A1 - Kathmann, Norbert A1 - Zimmermann, Ulrich S. A1 - Smolka, Michael N. A1 - Rapp, Michael A. A1 - Heinz, Andreas A1 - Huys, Quentin J. M. T1 - Pavlovian-to-Instrumental Transfer Effects Rely Less on Model-based Reinforcement Learning JF - Journal of cognitive neuroscience N2 - 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. Y1 - 2016 U6 - https://doi.org/10.1162/jocn_a_00945 SN - 0898-929X SN - 1530-8898 VL - 28 SP - 985 EP - 995 PB - MIT Press CY - Cambridge ER - TY - JOUR A1 - Kuschpel, Maxim S. A1 - Liu, Shuyan A1 - Schad, Daniel A1 - Heinzel, Stephan A1 - Heinz, Andreas A1 - Rapp, Michael A. T1 - Differential effects of wakeful rest, music and video game playing on working memory performance in the n-back task JF - Frontiers in psychology N2 - The interruption of learning processes by breaks filled with diverse activities is common in everyday life. We investigated the effects of active computer gaming and passive relaxation (rest and music) breaks on working memory performance. Young adults were exposed to breaks involving (i) eyes-open resting, (ii) listening to music and (iii) playing the video game “Angry Birds” before performing the n-back working memory task. Based on linear mixed-effects modeling, we found that playing the “Angry Birds” video game during a short learning break led to a decline in task performance over the course of the task as compared to eyes-open resting and listening to music, although overall task performance was not impaired. This effect was associated with high levels of daily mind wandering and low self-reported ability to concentrate. These findings indicate that video games can negatively affect working memory performance over time when played in between learning tasks. We suggest further investigation of these effects because of their relevance to everyday activity. KW - break interventions KW - computer games KW - mozart effect KW - working memory KW - attention KW - cognitive resources KW - mind wandering Y1 - 2015 U6 - https://doi.org/10.3389/fpsyg.2015.01683 SN - 1664-1078 IS - 6 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Schad, Daniel A1 - Juenger, Elisabeth A1 - Sebold, Miriam A1 - Garbusow, Maria A1 - Bernhardt, Nadine A1 - Javadi, Amir-Homayoun A1 - Zimmermann, Ulrich S. A1 - Smolka, Michael N. A1 - Heinz, Andreas A1 - Rapp, Michael A. A1 - Huys, Quentin J. M. T1 - Processing speed enhances model-based over model-free reinforcement learning in the presence of high working memory functioning JF - Frontiers in psychology N2 - 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. KW - decision-making KW - reward KW - cognitive abilities KW - model-based and model-free learning KW - fluid intelligence KW - habitual and goal-directed system Y1 - 2014 U6 - https://doi.org/10.3389/fpsyg.2014.01450 SN - 1664-1078 VL - 5 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Sebold, Miriam A1 - Garbusow, Maria A1 - Jetzschmann, P. A1 - Schad, Daniel A1 - Nebe, S. A1 - Schlagenhauf, Florian A1 - Heinz, A. A1 - Rapp, Michael A. A1 - Romanczuk-Seiferth, Nina T1 - Reward and avoidance learning in the context of aversive environments and possible implications for depressive symptoms JF - Psychopharmacology N2 - Background Aversive stimuli in the environment influence human actions. This includes valence-dependent influences on action selection, e.g., increased avoidance but decreased approach behavior. However, it is yet unclear how aversive stimuli interact with complex learning and decision-making in the reward and avoidance domain. Moreover, the underlying computational mechanisms of these decision-making biases are unknown. Methods To elucidate these mechanisms, 54 healthy young male subjects performed a two-step sequential decision-making task, which allows to computationally model different aspects of learning, e.g., model-free, habitual, and model-based, goal-directed learning. We used a within-subject design, crossing task valence (reward vs. punishment learning) with emotional context (aversive vs. neutral background stimuli). We analyzed choice data, applied a computational model, and performed simulations. Results Whereas model-based learning was not affected, aversive stimuli interacted with model-free learning in a way that depended on task valence. Thus, aversive stimuli increased model-free avoidance learning but decreased model-free reward learning. The computational model confirmed this effect: the parameter lambda that indicates the influence of reward prediction errors on decision values was increased in the punishment condition but decreased in the reward condition when aversive stimuli were present. Further, by using the inferred computational parameters to simulate choice data, our effects were captured. Exploratory analyses revealed that the observed biases were associated with subclinical depressive symptoms. Conclusion Our data show that aversive environmental stimuli affect complex learning and decision-making, which depends on task valence. Further, we provide a model of the underlying computations of this affective modulation. Finally, our finding of increased decision-making biases in subjects reporting subclinical depressive symptoms matches recent reports of amplified Pavlovian influences on action selection in depression and suggests a potential vulnerability factor for mood disorders. We discuss our findings in the light of the involvement of the neuromodulators serotonin and dopamine. KW - Reward learning KW - Avoidance learning KW - Reinforcement learning KW - Computational psychiatry KW - Decision-making KW - Affective modulation KW - Depression symptoms Y1 - 2019 U6 - https://doi.org/10.1007/s00213-019-05299-9 SN - 0033-3158 SN - 1432-2072 VL - 236 IS - 8 SP - 2437 EP - 2449 PB - Springer CY - New York ER - TY - JOUR A1 - Friedel, Eva A1 - Sebold, Miriam A1 - Kuitunen-Paul, Sören A1 - Nebe, Stephan A1 - Veer, Ilya M. A1 - Zimmermann, Ulrich S. A1 - Schlagenhauf, Florian A1 - Smolka, Michael N. A1 - Rapp, Michael A. A1 - Walter, Henrik A1 - Heinz, Andreas T1 - How Accumulated Real Life Stress Experience and Cognitive Speed Interact on Decision-Making Processes JF - Frontiers in human neuroscienc N2 - 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. KW - chronic stress KW - model-based learning KW - model-free learning KW - decision making KW - cognitive speed KW - real-life events Y1 - 2017 U6 - https://doi.org/10.3389/fnhum.2017.00302 SN - 1662-5161 VL - 11 SP - 1 EP - 9 PB - Frontiers Research Foundation CY - Lausanne ER -