@article{SchadNuthmannEngbert2012, author = {Schad, Daniel and Nuthmann, Antje and Engbert, Ralf}, title = {Your mind wanders weakly, your mind wanders deeply - objective measures reveal mindless reading at different levels}, series = {Cognition : international journal of cognitive science}, volume = {125}, journal = {Cognition : international journal of cognitive science}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0010-0277}, doi = {10.1016/j.cognition.2012.07.004}, pages = {179 -- 194}, year = {2012}, abstract = {When the mind wanders, attention turns away from the external environment and cognitive processing is decoupled from perceptual information. Mind wandering is usually treated as a dichotomy (dichotomy-hypothesis), and is often measured using self-reports. Here, we propose the levels of inattention hypothesis, which postulates attentional decoupling to graded degrees at different hierarchical levels of cognitive processing. To measure graded levels of attentional decoupling during reading we introduce the sustained attention to stimulus task (SAST), which is based on psychophysics of error detection. Under experimental conditions likely to induce mind wandering, we found that subjects were less likely to notice errors that required high-level processing for their detection as opposed to errors that only required low-level processing. Eye tracking revealed that before errors were overlooked influences of high- and low-level linguistic variables on eye fixations were reduced in a graded fashion, indicating episodes of mindless reading at weak and deep levels. Individual fixation durations predicted overlooking of lexical errors 5 s before they occurred. Our findings support the levels of inattention hypothesis and suggest that different levels of mindless reading can be measured behaviorally in the SAST. Using eye tracking to detect mind wandering online represents a promising approach for the development of new techniques to study mind wandering and to ameliorate its negative consequences.}, language = {en} } @article{SchadNicenboimBuerkneretal.2022, author = {Schad, Daniel and Nicenboim, Bruno and B{\"u}rkner, Paul-Christian and Betancourt, Michael and Vasishth, Shravan}, title = {Workflow techniques for the robust use of bayes factors}, series = {Psychological methods}, volume = {28}, journal = {Psychological methods}, number = {6}, publisher = {American Psychological Association}, address = {Washington}, issn = {1082-989X}, doi = {10.1037/met0000472}, pages = {1404 -- 1426}, year = {2022}, abstract = {Inferences about hypotheses are ubiquitous in the cognitive sciences. Bayes factors provide one general way to compare different hypotheses by their compatibility with the observed data. Those quantifications can then also be used to choose between hypotheses. While Bayes factors provide an immediate approach to hypothesis testing, they are highly sensitive to details of the data/model assumptions and it's unclear whether the details of the computational implementation (such as bridge sampling) are unbiased for complex analyses. Hem, we study how Bayes factors misbehave under different conditions. This includes a study of errors in the estimation of Bayes factors; the first-ever use of simulation-based calibration to test the accuracy and bias of Bayes factor estimates using bridge sampling; a study of the stability of Bayes factors against different MCMC draws and sampling variation in the data; and a look at the variability of decisions based on Bayes factors using a utility function. We outline a Bayes factor workflow that researchers can use to study whether Bayes factors are robust for their individual analysis. Reproducible code is available from haps://osf.io/y354c/.
Translational Abstract
In psychology and related areas, scientific hypotheses are commonly tested by asking questions like "is [some] effect present or absent." Such hypothesis testing is most often carried out using frequentist null hypothesis significance testing (NIIST). The NHST procedure is very simple: It usually returns a p-value, which is then used to make binary decisions like "the effect is present/abscnt." For example, it is common to see studies in the media that draw simplistic conclusions like "coffee causes cancer," or "coffee reduces the chances of geuing cancer." However, a powerful and more nuanced alternative approach exists: Bayes factors. Bayes factors have many advantages over NHST. However, for the complex statistical models that arc commonly used for data analysis today, computing Bayes factors is not at all a simple matter. In this article, we discuss the main complexities associated with computing Bayes factors. This is the first article to provide a detailed workflow for understanding and computing Bayes factors in complex statistical models. The article provides a statistically more nuanced way to think about hypothesis testing than the overly simplistic tendency to declare effects as being "present" or "absent".}, language = {en} } @article{SchadRisseSlatteryetal.2014, author = {Schad, Daniel and Risse, Sarah and Slattery, Timothy and Rayner, Keith}, title = {Word frequency in fast priming: Evidence for immediate cognitive control of eye movements during reading}, series = {Visual cognition}, volume = {22}, journal = {Visual cognition}, number = {3-4}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {1350-6285}, doi = {10.1080/13506285.2014.892041}, pages = {390 -- 414}, year = {2014}, abstract = {Numerous studies have demonstrated effects of word frequency on eye movements during reading, but the precise timing of this influence has remained unclear. The fast priming paradigm was previously used to study influences of related versus unrelated primes on the target word. Here, we use this procedure to investigate whether the frequency of the prime word has a direct influence on eye movements during reading when the prime-target relation is not manipulated. We found that with average prime intervals of 32 ms readers made longer single fixation durations on the target word in the low than in the high frequency prime condition. Distributional analyses demonstrated that the effect of prime frequency on single fixation durations occurred very early, supporting theories of immediate cognitive control of eye movements. Finding prime frequency effects only 207 ms after visibility of the prime and for prime durations of 32 ms yields new time constraints for cognitive processes controlling eye movements during reading. Our variant of the fast priming paradigm provides a new approach to test early influences of word processing on eye movement control during reading.}, language = {en} } @article{SperlichSchadLaubrock2015, author = {Sperlich, Anja and Schad, Daniel and Laubrock, Jochen}, title = {When preview information starts to matter}, series = {Journal of cognitive psychology}, volume = {27}, journal = {Journal of cognitive psychology}, number = {5}, publisher = {Routledge, Taylor \& Francis Group}, address = {Abingdon}, issn = {2044-5911}, doi = {10.1080/20445911.2014.993990}, pages = {511 -- 530}, year = {2015}, abstract = {How is reading development reflected in eye-movement measures? How does the perceptual span change during the initial years of reading instruction? Does parafoveal processing require competence in basic word-decoding processes? We report data from the first cross-sectional measurement of the perceptual span of German beginning readers (n = 139), collected in the context of the large longitudinal PIER (Potsdamer Intrapersonale Entwicklungsrisiken/Potsdam study of intra-personal developmental risk factors) study of intrapersonal developmental risk factors. Using the moving-window paradigm, eye movements of three groups of students (Grades 1-3) were measured with gaze-contingent presentation of a variable amount of text around fixation. Reading rate increased from Grades 1-3, with smaller increases for higher grades. Perceptual-span results showed the expected main effects of grade and window size: fixation durations and refixation probability decreased with grade and window size, whereas reading rate and saccade length increased. Critically, for reading rate, first-fixation duration, saccade length and refixation probability, there were significant interactions of grade and window size that were mainly based on the contrast between Grades 3 and 2 rather than Grades 2 and 1. Taken together, development of the perceptual span only really takes off between Grades 2 and 3, suggesting that efficient parafoveal processing presupposes that basic processes of reading have been mastered.}, language = {en} } @article{SeboldNebeGarbusowetal.2017, author = {Sebold, Miriam Hannah and Nebe, Stephan and Garbusow, Maria and Guggenmos, Matthias and Schad, Daniel and Beck, Anne and Kuitunen-Paul, S{\"o}ren and Sommer, Christian and Frank, Robin and Neu, Peter and Zimmermann, Ulrich S. and Rapp, Michael A. and Smolka, Michael N. and Huys, Quentin J. M. and Schlagenhauf, Florian and Heinz, Andreas}, title = {When Habits Are Dangerous: Alcohol Expectancies and Habitual Decision Making Predict Relapse in Alcohol Dependence}, series = {Biological psychiatry : a journal of psychiatric neuroscience and therapeutics ; a publication of the Society of Biological Psychiatry}, volume = {82}, journal = {Biological psychiatry : a journal of psychiatric neuroscience and therapeutics ; a publication of the Society of Biological Psychiatry}, publisher = {Elsevier}, address = {New York}, issn = {0006-3223}, doi = {10.1016/j.biopsych.2017.04.019}, pages = {847 -- 856}, year = {2017}, abstract = {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.}, language = {en} } @article{SchadBetancourtVasishth2021, author = {Schad, Daniel and Betancourt, Michael and Vasishth, Shravan}, title = {Toward a principled Bayesian workflow in cognitive science}, series = {Psychological methods}, volume = {26}, journal = {Psychological methods}, number = {1}, publisher = {American Psychological Association}, address = {Washington}, issn = {1082-989X}, doi = {10.1037/met0000275}, pages = {103 -- 126}, year = {2021}, abstract = {Experiments in research on memory, language, and in other areas of cognitive science are increasingly being analyzed using Bayesian methods. This has been facilitated by the development of probabilistic programming languages such as Stan, and easily accessible front-end packages such as brms. The utility of Bayesian methods, however, ultimately depends on the relevance of the Bayesian model, in particular whether or not it accurately captures the structure of the data and the data analyst's domain expertise. Even with powerful software, the analyst is responsible for verifying the utility of their model. To demonstrate this point, we introduce a principled Bayesian workflow (Betancourt, 2018) to cognitive science. Using a concrete working example, we describe basic questions one should ask about the model: prior predictive checks, computational faithfulness, model sensitivity, and posterior predictive checks. The running example for demonstrating the workflow is data on reading times with a linguistic manipulation of object versus subject relative clause sentences. This principled Bayesian workflow also demonstrates how to use domain knowledge to inform prior distributions. It provides guidelines and checks for valid data analysis, avoiding overfitting complex models to noise, and capturing relevant data structure in a probabilistic model. Given the increasing use of Bayesian methods, we aim to discuss how these methods can be properly employed to obtain robust answers to scientific questions.}, language = {en} } @article{SchadEngbert2012, author = {Schad, Daniel and Engbert, Ralf}, title = {The zoom lens of attention simulating shuffled versus normal text reading using the SWIFT model}, series = {Visual cognition}, volume = {20}, journal = {Visual cognition}, number = {4-5}, publisher = {Wiley}, address = {Hove}, issn = {1350-6285}, doi = {10.1080/13506285.2012.670143}, pages = {391 -- 421}, year = {2012}, abstract = {Assumptions on the allocation of attention during reading are crucial for theoretical models of eye guidance. The zoom lens model of attention postulates that attentional deployment can vary from a sharp focus to a broad window. The model is closely related to the foveal load hypothesis, i.e., the assumption that the perceptual span is modulated by the difficulty of the fixated word. However, these important theoretical concepts for cognitive research have not been tested quantitatively in eye movement models. Here we show that the zoom lens model, implemented in the SWIFT model of saccade generation, captures many important patterns of eye movements. We compared the model's performance to experimental data from normal and shuffled text reading. Our results demonstrate that the zoom lens of attention might be an important concept for eye movement control in reading.}, language = {en} } @article{InhoffSeymourSchadetal.2010, author = {Inhoff, Albrecht W. and Seymour, Bradley A. and Schad, Daniel and Greenberg, Seth}, title = {The size and direction of saccadic curvatures during reading}, issn = {0042-6989}, year = {2010}, abstract = {Eye movements during the reading of multi-line pages of texts were analyzed to determine the trajectory of reading saccades. The results of two experiments showed that the trajectory of the majority of forward-directed saccades was negatively biased, i.e., the trajectory fell below the start and end location of the saccadic movement. This is attributed to a global top-to-bottom orienting of attention. The curvature size and the proportion of negative trajectories were diminished when linguistic processing demands were high and when the beginning lines of a page were read. Longer pre-saccadic fixations also yielded smaller saccadic curvatures, and they resulted in fewer negatively curved forward-directed saccades in Experiment 1 although not in Experiment 2. These findings indicate that the top-to- bottom pull of saccadic trajectories is modulated by processing demands and processing opportunities. The results are in general agreement with a time-locked attraction-inhibition hypothesis, according to which the horizontal movement component of a saccade is initially subject to an automatic top-to-bottom orienting of attention that is subsequently inhibited.}, language = {en} } @article{InhoffSeymourSchadetal.2010, author = {Inhoff, Albrecht W. and Seymour, Bradley A. and Schad, Daniel and Greenberg, Seth}, title = {The size and direction of saccadic curvatures during reading}, issn = {0042-6989}, doi = {10.1016/j.visres.2010.03.025}, year = {2010}, abstract = {e movements during the reading of multi-line pages of texts were analyzed to determine the trajectory of reading saccades. The results of two experiments showed that the trajectory of the majority of forward-directed saccades was negatively biased, i.e., the trajectory fell below the start and end location of the saccadic movement. This is attributed to a global top-to-bottom orienting of attention. The curvature size and the proportion of negative trajectories were diminished when linguistic processing demands were high and when the beginning lines of a page were read. Longer pre-saccadic fixations also yielded smaller saccadic curvatures, and they resulted in fewer negatively curved forward-directed saccades in Experiment 1 although not in Experiment 2. These findings indicate that the top-to- bottom pull of saccadic trajectories is modulated by processing demands and processing opportunities. The results are in general agreement with a time-locked attraction-inhibition hypothesis, according to which the horizontal movement component of a saccade is initially subject to an automatic top-to-bottom orienting of attention that is subsequently inhibited.}, language = {en} } @article{SchadVasishth2022, author = {Schad, Daniel and Vasishth, Shravan}, title = {The posterior probability of a null hypothesis given a statistically significant result}, series = {The quantitative methods for psychology}, volume = {18}, journal = {The quantitative methods for psychology}, number = {2}, publisher = {University of Montreal, Department of Psychology}, address = {Montreal}, issn = {1913-4126}, doi = {10.20982/tqmp.18.2.p011}, pages = {130 -- 141}, year = {2022}, abstract = {When researchers carry out a null hypothesis significance test, it is tempting to assume that a statistically significant result lowers Prob(H0), the probability of the null hypothesis being true. Technically, such a statement is meaningless for various reasons: e.g., the null hypothesis does not have a probability associated with it. However, it is possible to relax certain assumptions to compute the posterior probability Prob(H0) under repeated sampling. We show in a step-by-step guide that the intuitively appealing belief, that Prob(H0) is low when significant results have been obtained under repeated sampling, is in general incorrect and depends greatly on: (a) the prior probability of the null being true; (b) type-I error rate, (c) type-II error rate, and (d) replication of a result. Through step-by-step simulations using open-source code in the R System of Statistical Computing, we show that uncertainty about the null hypothesis being true often remains high despite a significant result. To help the reader develop intuitions about this common misconception, we provide a Shiny app (https://danielschad.shinyapps.io/probnull/). We expect that this tutorial will help researchers better understand and judge results from null hypothesis significance tests.}, language = {en} } @article{ChenNebeMojtahedzadehetal.2020, author = {Chen, Hao and Nebe, Stephan and Mojtahedzadeh, Negin and Kuitunen-Paul, Soren and Garbusow, Maria and Schad, Daniel and Rapp, Michael A. and Huys, Quentin J. M. and Heinz, Andreas and Smolka, Michael N.}, title = {Susceptibility to interference between Pavlovian and instrumental control is associated with early hazardous alcohol use}, series = {Addiction biology}, volume = {26}, journal = {Addiction biology}, number = {4}, publisher = {Wiley}, address = {Hoboken}, issn = {1355-6215}, doi = {10.1111/adb.12983}, pages = {1 -- 14}, year = {2020}, abstract = {Pavlovian-to-instrumental transfer (PIT) tasks examine the influence of Pavlovian stimuli on ongoing instrumental behaviour. Previous studies reported associations between a strong PIT effect, high-risk drinking and alcohol use disorder. This study investigated whether susceptibility to interference between Pavlovian and instrumental control is linked to risky alcohol use in a community sample of 18-year-old male adults. Participants (N = 191) were instructed to 'collect good shells' and 'leave bad shells' during the presentation of appetitive (monetary reward), aversive (monetary loss) or neutral Pavlovian stimuli. We compared instrumental error rates (ER) and functional magnetic resonance imaging (fMRI) brain responses between the congruent and incongruent conditions, as well as among high-risk and low-risk drinking groups. On average, individuals showed a substantial PIT effect, that is, increased ER when Pavlovian cues and instrumental stimuli were in conflict compared with congruent trials. Neural PIT correlates were found in the ventral striatum and the dorsomedial and lateral prefrontal cortices (lPFC). Importantly, high-risk drinking was associated with a stronger behavioural PIT effect, a decreased lPFC response and an increased neural response in the ventral striatum on the trend level. Moreover, high-risk drinkers showed weaker connectivity from the ventral striatum to the lPFC during incongruent trials. Our study links interference during PIT to drinking behaviour in healthy, young adults. High-risk drinkers showed higher susceptibility to Pavlovian cues, especially when they conflicted with instrumental behaviour, indicating lower interference control abilities. Increased activity in the ventral striatum (bottom-up), decreased lPFC response (top-down), and their altered interplay may contribute to poor interference control in the high-risk drinkers.}, language = {en} } @article{SommerGarbusowJuengeretal.2017, author = {Sommer, C. and Garbusow, Maria and Juenger, E. and Pooseh, S. and Bernhardt, Nadine and Birkenstock, J. and Schad, Daniel and Jabs, B. and Gloeckler, T. and Huys, Quentin J. M. and Heinz, A. and Smolka, Michael N. and Zimmermann, Ulrich S.}, title = {Strong seduction: impulsivity and the impact of contextual cues on instrumental behavior in alcohol dependence}, series = {Translational Psychiatry}, volume = {7}, journal = {Translational Psychiatry}, publisher = {Nature Publ. Group}, address = {New York}, issn = {2158-3188}, doi = {10.1038/tp.2017.158}, pages = {1209 -- 1222}, year = {2017}, abstract = {Alcohol-related cues acquire incentive salience through Pavlovian conditioning and then can markedly affect instrumental behavior of alcohol-dependent patients to promote relapse. However, it is unclear whether similar effects occur with alcohol-unrelated cues. We tested 116 early-abstinent alcohol-dependent patients and 91 healthy controls who completed a delay discounting task to assess choice impulsivity, and a Pavlovian-to-instrumental transfer (PIT) paradigm employing both alcohol-unrelated and alcohol-related stimuli. To modify instrumental choice behavior, we tiled the background of the computer screen either with conditioned stimuli (CS) previously generated by pairing abstract pictures with pictures indicating monetary gains or losses, or with pictures displaying alcohol or water beverages. CS paired to money gains and losses affected instrumental choices differently. This PIT effect was significantly more pronounced in patients compared to controls, and the group difference was mainly driven by highly impulsive patients. The PIT effect was particularly strong in trials in which the instrumental stimulus required inhibition of instrumental response behavior and the background CS was associated to monetary gains. Under that condition, patients performed inappropriate approach behavior, contrary to their previously formed behavioral intention. Surprisingly, the effect of alcohol and water pictures as background stimuli resembled that of aversive and appetitive CS, respectively. These findings suggest that positively valenced background CS can provoke dysfunctional instrumental approach behavior in impulsive alcohol-dependent patients. Consequently, in real life they might be easily seduced by environmental cues to engage in actions thwarting their long-term goals. Such behaviors may include, but are not limited to, approaching alcohol.}, language = {en} } @article{RabovskySchadAbdelRahman2021, author = {Rabovsky, Milena and Schad, Daniel and Abdel Rahman, Rasha}, title = {Semantic richness and density effects on language production}, series = {Journal of experimental psychology : Learning, memory, and cognition}, volume = {47}, journal = {Journal of experimental psychology : Learning, memory, and cognition}, number = {3}, publisher = {American Psychological Association}, address = {Washington}, issn = {0278-7393}, doi = {10.1037/xlm0000940}, pages = {508 -- 517}, year = {2021}, abstract = {Language production ultimately aims to convey meaning. Yet words differ widely in the richness and density of their semantic representations, and these differences impact conceptual and lexical processes during speech planning. Here, we replicated the recent finding that semantic richness, measured as the number of associated semantic features according to semantic feature production norms, facilitates object naming. In contrast, intercorrelational semantic feature density, measured as the degree of intercorrelation of a concept's features, presumably resulting in the coactivation of closely related concepts, has an inhibitory influence. We replicated the behavioral effects and investigated their relative time course and electrophysiological correlates. Both the facilitatory effect of high semantic richness and the inhibitory influence of high feature density were reflected in an increased posterior positivity starting at about 250 ms, in line with previous reports of posterior positivities in paradigms employing contextual manipulations to induce semantic interference during language production. Furthermore, amplitudes at the same posterior electrode sites were positively correlated with object naming times between about 230 and 380 ms. The observed effects follow naturally from the assumption of conceptual facilitation and simultaneous lexical competition and are difficult to explain by language production theories dismissing lexical competition.}, language = {en} } @article{SeboldGarbusowJetzschmannetal.2019, author = {Sebold, Miriam Hannah and Garbusow, Maria and Jetzschmann, P. and Schad, Daniel and Nebe, S. and Schlagenhauf, Florian and Heinz, A. and Rapp, Michael A. and Romanczuk-Seiferth, Nina}, title = {Reward and avoidance learning in the context of aversive environments and possible implications for depressive symptoms}, series = {Psychopharmacology}, volume = {236}, journal = {Psychopharmacology}, number = {8}, publisher = {Springer}, address = {New York}, issn = {0033-3158}, doi = {10.1007/s00213-019-05299-9}, pages = {2437 -- 2449}, year = {2019}, abstract = {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.}, language = {en} } @article{SchadJuengerSeboldetal.2014, author = {Schad, Daniel and Juenger, Elisabeth and Sebold, Miriam Hannah and Garbusow, Maria and Bernhardt, Nadine and Javadi, Amir-Homayoun and Zimmermann, Ulrich S. and Smolka, Michael N. and Heinz, Andreas and Rapp, Michael A. and Huys, Quentin J. M.}, title = {Processing speed enhances model-based over model-free reinforcement learning in the presence of high working memory functioning}, series = {Frontiers in psychology}, volume = {5}, journal = {Frontiers in psychology}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-1078}, doi = {10.3389/fpsyg.2014.01450}, pages = {10}, year = {2014}, abstract = {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.}, language = {en} } @article{GarbusowSchadSommeretal.2014, author = {Garbusow, Maria and Schad, Daniel and Sommer, Christian and Juenger, Elisabeth and Sebold, Miriam Hannah and Friedel, Eva and Wendt, Jean and Kathmann, Norbert and Schlagenhauf, Florian and Zimmermann, Ulrich S. and Heinz, Andreas and Huys, Quentin J. M. and Rapp, Michael A.}, title = {Pavlovian-to-instrumental transfer in alcohol dependence: a pilot study}, series = {Neuropsychobiology : international journal of experimental and clinical research in biological psychiatry, pharmacopsychiatry, Biological Psychology/Pharmacopsychology and Pharmacoelectroencephalography}, volume = {70}, journal = {Neuropsychobiology : international journal of experimental and clinical research in biological psychiatry, pharmacopsychiatry, Biological Psychology/Pharmacopsychology and Pharmacoelectroencephalography}, number = {2}, publisher = {Karger}, address = {Basel}, issn = {0302-282X}, doi = {10.1159/000363507}, pages = {111 -- 121}, year = {2014}, abstract = {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.}, language = {en} } @article{SeboldSchadNebeetal.2016, author = {Sebold, Miriam Hannah and Schad, Daniel and Nebe, Stephan and Garbusow, Maria and Juenger, Elisabeth and Kroemer, Nils B. and Kathmann, Norbert and Zimmermann, Ulrich S. and Smolka, Michael N. and Rapp, Michael A. and Heinz, Andreas and Huys, Quentin J. M.}, title = {Pavlovian-to-Instrumental Transfer Effects Rely Less on Model-based Reinforcement Learning}, series = {Journal of cognitive neuroscience}, volume = {28}, journal = {Journal of cognitive neuroscience}, publisher = {MIT Press}, address = {Cambridge}, issn = {0898-929X}, doi = {10.1162/jocn_a_00945}, pages = {985 -- 995}, year = {2016}, abstract = {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.}, 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 A. 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} } @article{GarbusowNebeSommeretal.2019, author = {Garbusow, Maria and Nebe, Stephan and Sommer, Christian and Kuitunen-Paul, S{\"o}ren and Sebold, Miriam Hannah and Schad, Daniel and Friedel, Eva and Veer, Ilya M. and Wittchen, Hans-Ulrich and Rapp, Michael A. and Ripke, Stephan and Walter, Henrik and Huys, Quentin J. M. and Schlagenhauf, Florian and Smolka, Michael N. and Heinz, Andreas}, title = {Pavlovian-To-Instrumental Transfer and Alcohol Consumption in Young Male Social Drinkers}, series = {Journal of Clinical Medicine}, volume = {8}, journal = {Journal of Clinical Medicine}, number = {8}, publisher = {MDPI}, address = {Basel}, issn = {2077-0383}, doi = {10.3390/jcm8081188}, pages = {14}, year = {2019}, abstract = {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.}, language = {en} } @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 A. 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} }