Biology subjects

Hauser, T. U.

Publications and source records attributed to Hauser, T. U..

18 recordsLinked to original sources

bioRxiv2026

Dorsomedial prefrontal cortex acts as an integrative hub during information gathering

Gathering information before committing to a choice is critical in real-world decision making, and biases thereof are hallmark features of psychiatric disorders. Here, we study the behavioural and neural mechanisms that guide information gathering and characterise several key cognitive constituents, including escalating urgency and systematically biased temporal weighting of information. Using fMRI, we identify an integrated information gathering signal in ventromedial and dorsomedial prefrontal cortices (dmPFC), signalling an overall likelihood for continued sampling of information. Teasing this signal apart, we find distinct neural circuits encoding separable information-gathering constituents: whilst an urgency signal primarily engaged locus coeruleus and dmPFC, accumulated evidence was represented in anterio-medial PFC, and evidence-strength prediction errors were computed in ventral striatum and dmPFC. These findings indicate that information gathering arises from functionally distinguishable prefrontal-subcortical computations that converge within medial prefrontal cortex, providing a mechanistic framework for understanding aberrant sampling in psychiatric conditions, including schizophrenia and obsessive-compulsive disorder.

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bioRxiv2026

Frontotemporal cortex flexibly adapts latent structural representations

Humans excel at navigating complex environments by forming abstract structural representations that can be flexibly updated when environments change. Here, we examine how the brain dynamically reconfigures these internal models in response to covert changes in latent hierarchies. Using a novel inference task and fMRI repetition suppression, we find that stable relational knowledge is encoded in medial orbitofrontal cortex (mOFC), while structural changes trigger transient representations across hippocampal and prefrontal regions. Newly inferred associations are first encoded in anterior medial frontal cortex (amFC) and migrate ventrally to mOFC when settling. In contrast, outdated associations transiently engage frontopolar cortex and hippocampus, with the hippocampus, but not frontal areas, retaining a residual memory trace. Notably, the strength of early novel signals in amFC and hippocampus tracks individual differences in behavioural adaptation. Together, these results characterise mechanisms supporting adaptive structural reconfiguration in the human brain, with implications for cognitive inflexibility in psychiatric disorders. SIGNIFICANCE STATEMENTThe brain relies on internal models of hidden environmental structure, yet how these models are revised when the world changes remains unclear. We developed a novel task and neuroimaging approach that allowed us to trace the emergence, maintenance, and dissolution of latent structural representations in humans. Stable representations were encoded in medial orbitofrontal cortex, whereas newly formed and outdated associations followed distinct temporal trajectories across frontal and hippocampal regions. Outdated representations transiently recruited frontopolar cortex but persisted in hippocampus after becoming behaviorally irrelevant. Neural signatures of updating predicted individual differences in adaptation, revealing candidate mechanisms through which cognitive flexibility, and its impairment in psychiatric disorders, may arise.

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bioRxiv2026

Dissociable Microstructural Correlates of Learning Rate and Learning Noise in Gamified Reward-Based Decision-Making

Humans learn which actions yield the highest rewards through trial and error, gradually forming expectations about outcomes. Yet, people differ substantially in how quickly and precisely they learn. Such individual variability may partly be explained by differences in the brains microstructural organisation. In this large-scale study, 248 participants completed a gamified reward-learning task and underwent quantitative MRI to assess whole-brain microstructural indices of myelination (R1) and cortical iron (R2*). Using computational modelling, we quantified participants learning rates and learning noise, reflecting variability in how reward information is updated over time. Whole-brain voxel-based quantification analyses revealed that increased myelination in the cerebellum was associated with a higher learning rate, whereas learning noise was linked to increased myelination and iron concentration in the precentral gyrus. Together, these findings show that reward learning is not a unitary process but is instead shaped by distinct neurobiological pathways that support learning precision and noise. This work highlights how microstructural variation in sensorimotor and associative cortices contributes to stable versus variable reward learning behaviour across individuals. Significance StatementThis study deepens our understanding of the neural microstructures involved in reward-related decision-making by employing advanced quantitative imaging and computational modelling to investigate brain microstructures associated with individual differences in noisy reward learning and decision-making, using a gamified task. Our results reveal distinct brain microstructures for learning rate and learning noise, which have not been reported before, thereby providing a new understanding of what may be involved in reward-based decision-making. These results provide new potential target pathways for future clinical research in psychiatric disorders where reward processing is implicated, such as ADHD and OCD.

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bioRxiv2025

Dopamine drives a positive reward bias on human reinforcement learning

Formal theories of reinforcement learning (RL) prescribe a clearly defined function for dopamine, namely modulating learning via reward prediction errors (RPEs). Yet, empirical evidence in humans remains scarce, and recent advances introducing noisy RL cast doubt on a simple one-to-one mapping between neurotransmitters and computational mechanisms. Here, we detail a double-blind, placebo-controlled, randomised pharmacological study using the dopamine precursor L-DOPA, while healthy volunteers performed a volatile two-armed bandit task. Behaviourally, L-DOPA decreased switching behaviour following below-average rewards. Algorithmic RL modelling of human behaviour supported a dual effect of L-DOPA on the rate and precision of learning. By leveraging recurrent neural networks (RNNs) as implementational models of RL, we explain this dual effect through a single inference-time modulation, whereby L-DOPA triggers a positive reward bias at the input of the recurrent layer that implements RL. Our findings highlight a unifying mechanism at the implementation level that explain seemingly disparate algorithmic effects of dopamine.

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bioRxiv2025

Cortical Microstructural Variations Explain Individual Differences in Gamified Exploration-Exploitation Behaviours

The exploration-exploitation trade-off is ubiquitous in our everyday lives, and individuals display considerable variability in their preferred decision-making strategies. Most previous work pertaining to neural signatures of exploration is restricted to functional pathways. However, the specific contributions of cortical microarchitectures to high-level cognitive processes such as decision-making are as yet unknown. Here, we investigated the neuroanatomical foundations of inter-individual variability in decision-making strategies. To this end, 122 healthy participants completed a gamified multi-armed bandit paradigm aimed at teasing apart distinct exploration-exploitation decision strategies. We also collected whole-brain quantitative MRI maps indexing microstructural features of cortical myelination and iron content. Through computational modelling, we disentangled individual-specific exploration strategies, including value-free random exploration. Whole-brain regression analyses identified significant associations between value-free exploration and increased cortical myelination in right frontal brain areas with reported links to impulsivity. By elucidating the brain microstructural correlates of distinct exploration-exploitation strategies, we aimed to further our understanding of why individuals differ in their decision-making capabilities, and how decision-making may become aberrant in mental health conditions.

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bioRxiv2025

Biased replay of aversive and uncertain outcomes underlies irrational decision making

Humans often make irrational decisions when facing uncertain or aversive future events despite careful deliberation. How we make choices, including irrational ones1,2, has been the object of extensive study both behaviourally and neurally3-6 and is the focus of influential behavioural economic theories7-9. Yet, little is known about how these (irrational) decisions are carved out in the brain. Here, using magnetoencephalography (MEG), we show that the construction and outcome evaluation of irrational decisions involves rapid, sequential state reactivation, or "replay."10. During deliberation, we show that forward replay is biased towards choice options with more negative and uncertain outcomes, with this bias further amplified immediately preceding irrational choice. Likewise, post-decision evaluation relates to replay in a choice-dependent manner. Following irrational choices, relief-like signals were evident as stronger backward replay of worse counterfactual options, while after rational decisions, regret-like signals appeared as stronger backward replay of better counterfactual options. Together, these findings suggest that neural replay shapes both the formation and reflection of irrational decisions, and poise replay as a candidate mechanism underlying pervasive decision biases in humans.

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bioRxiv2024

Indecision and recency-weighted evidence integration in non-clinical and clinical settings

Biases in information gathering are common in the general population and can reach pathological extremes in paralysing indecisiveness, as in obsessive-compulsive disorder (OCD). Here, we adopt a new perspective on information gathering and demonstrate an information integration bias where most recent information is over-weighted by means of evidence strength updates ({Delta}ES). In a large, crowd-sourced sample (N=5,237), we find reduced {Delta}ES-weighting drives indecisiveness along an OC spectrum. We replicate the attenuated {Delta}ES- weighting in a second lab-based study (N=105) that includes a transdiagnostic OC spectrum encompassing OCD and generalised anxiety patients. Using magnetoencephalography (MEG), we trace {Delta}ES signals to a late neural signal peaking around 920 ms. Critically, high-OC participants show an attenuated neural {Delta}ES signal in medio-frontal areas while other decision- relevant processes remain intact. Our findings establish biased information-weighting as a key driver of information gathering, where attenuated {Delta}ES can lead to indecisiveness across an OC spectrum.

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bioRxiv2023

Early life adversities affect expected value signaling in the adult brain

BackgroundEarly adverse experiences are assumed to affect fundamental processes of reward learning and decision-making. However, computational neuroimaging studies investigating these circuits are sparse and limited to studies that investigated adversities retrospectively in adolescent samples. MethodsWe used prospective data from a longitudinal birth cohort study (n=156, 87 females, mean age=32.2) to investigate neurocomputational components underlying reinforcement learning in an fMRI-based passive avoidance task. We applied a principal component analysis to capture common variation across seven prenatal and postnatal adversity measures. The resulting adversity factors (factor 1: postnatal psychosocial adversities and prenatal maternal smoking, factor 2: prenatal maternal stress and obstetric adversity, and factor 3: lower maternal stimulation) and single adversity measures were then linked to computational markers of reward learning (i.e. expected value, prediction errors) in the core reward network. ResultsUsing the adversity factors, we found that adversities were linked to lower expected value representation in striatum, ventromedial prefrontal cortex (vmPFC) and anterior cingulate cortex (ACC). Expected value encoding in vmPFC further mediated the relationship between adversities and psychopathology. In terms of specific adversity effects, we found that obstetric adversity was associated with lower prediction error signaling in the vmPFC and ACC, whereas lower maternal stimulation was related to lower expected value encoding in the striatum, vmPFC, and ACC. ConclusionsOur results suggested that adverse experiences have a long-term disruptive effect on reward learning in several important reward-related brain regions, which can be associated with non-optimal decision-making and thereby increase the vulnerability of developing psychopathology.

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bioRxiv2022

Uncertain Precision: Neurobiological and Physiological Correlates of Conservative Confidence Bias

Correctly estimating the influence of uncertainty on our decisions is a critical metacognitive faculty. However, the relationship between sensory uncertainty (or its inverse, precision), decision accuracy, and subjective confidence is currently unclear. Although some findings indicate that healthy adults exhibit an illusion of over-confidence, under-confidence in response to sensory uncertainty has also been reported. One reason for this ambiguity is that stimulus intensity and precision are typically confounded with one another, limiting the ability to assess their independent contribution to metacognitive biases. Here we report four psychophysical experiments controlling these factors, finding that healthy human participants are systematically under-confident when discriminating low-precision stimuli. This bias remains even when decision accuracy and reaction time are accounted for, indicating that a performance-independent computation partially underpins the influence of sensory precision on confidence. We further show that this influence is linked to fluctuations in arousal and individual differences in the neuroanatomy of the left superior parietal lobe and middle insula. These results illuminate the neural and physiological correlates of precision misperception in metacognition. Significance StatementThe ability to recognize the influence of sensory uncertainty on our decisions underpins the veracity of self-monitoring, or metacognition. In the extreme, a systematic confidence bias can undermine decision accuracy and potentially underpin disordered self-insight in neuropsychiatric illness. Previously it was unclear if metacognition accurately reflects changes in sensory precision, in part due to confounding effects of stimulus intensity and precision. Here we overcome these limitations to repeatedly demonstrate a robust precision-related confidence bias. Further, we reveal novel neuroanatomical and physiological markers underlying this metacognitive bias. These results suggest a unique state-based computational mechanism may drive subjective confidence biases and further provide new avenues for investigating maladaptive awareness of uncertainty in neuropsychiatric disorders.

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bioRxiv2021

Boosting serotonin increases information gathering by reducing subjective cognitive costs

Serotonin is implicated in the valuation of aversive costs, such as delay or physical effort. However, its role in governing sensitivity to cognitive effort, for example deliberation costs during information gathering, is unclear. We show that week-long treatment with a serotonergic antidepressant enhances a willingness to gather information when trying to maximize reward. Using computational modelling, we show this arises from a diminished sensitivity to subjective deliberation costs during the sampling process. This result is consistent with the notion that serotonin alleviates sensitivity to aversive costs in a domain-general fashion, with implications for its potential contribution to a positive impact on motivational deficits in psychiatric disorders.

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bioRxiv2021

Children are full of optimism, but those rose-tinted glasses are fading: reduced learning from negative outcomes drives hyperoptimism in children.

Believing that good things will happen in life is essential to maintain motivation and achieve highly ambitious goals. This optimism bias, the overestimation of positive outcomes, may be particularly important during childhood when motivation must be maintained in the face of negative outcomes. In a learning task, we have thus studied the mechanisms underlying the development of optimism bias. Investigating children (8-9 year-olds), early (12-13 year-olds) and late adolescents (16-17 year-olds), we find a consistent optimism bias across age groups. However, children were particularly hyperoptimistic, with the optimism bias decreasing with age. Using computational modelling, we show that this was driven by a reduced learning from worse-than-expected outcomes, and this reduced learning explains why children are hyperoptimistic. Our findings thus show that insensitivity to bad outcomes in childhood helps to prevent taking on an overly realistic perspective and maintain motivation.

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bioRxiv2021

Reliability of web-based affective auditory stimulus presentation

Web-based experimental testing has seen an exponential growth in psychology and cognitive neuroscience. However, paradigms involving affective auditory stimuli have yet to adapt to the online approach due to concerns about the lack of experimental control and other technical challenges. In this study, we assessed if sounds commonly used to evoke affective responses in-lab can be used online. Using recent developments to increase sound presentation quality, we selected 15 commonly used sound stimuli and assessed their impact on valence and arousal states in a web-based experiment. Our results reveal good test-retest reliability and good internal consistency, with results comparable to in-lab studies. Additionally, we compared a variety of previously used unpleasant stimuli, allowing us to identify the most aversive of these sounds. Our findings demonstrate that affective sounds can be reliably delivered through web-based platforms, which helps facilitate the development of new auditory paradigms for affective online experiments.

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bioRxiv2020

Tabula-rasa exploration decreases during youth and is linked to ADHD symptoms

During childhood and adolescence, exploring the unknown is important to build a better model of the world. This means that youths have to regularly solve the exploration-exploitation trade-off, a dilemma in which adults are known to deploy a mixture of computationally light and heavy exploration strategies. In this developmental study, we investigated how youths (aged 8 to 17) performed an exploration task that allows us to dissociate these different exploration strategies. Using computational modelling, we demonstrate that tabula-rasa exploration, a computationally light exploration heuristic, is used to a higher degree in children and younger adolescents compared to older adolescents. Additionally, we show that this tabula-rasa exploration is more extensively used by youths with high attention-deficit/hyperactivity disorder (ADHD) traits. In the light of ongoing brain development, our findings show that children and younger adolescents use computationally less burdensome strategies, but that an excessive use thereof might be a risk for mental health conditions.

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bioRxiv2019

White Matter Microstructure and its Relation to Clinical Features of Obsessive-Compulsive Disorder: Findings from the ENIGMA OCD Working Group

ImportanceMicrostructural alterations in cortico-subcortical connections are thought to be present in Obsessive-Compulsive Disorder (OCD). However, prior studies have yielded inconsistent findings, perhaps because small sample sizes provided insufficient power to detect subtle abnormalities. ObjectiveTo investigate microstructural white matter alterations and their relation to clinical features in the largest dataset of adult and pediatric OCD to date. Design, Setting, and ParticipantsIn this cross-sectional case-control magnetic resonance study, we investigated diffusion tensor imaging metrics from 700 adult patients and 645 adult controls, as well as 174 pediatric patients and 144 pediatric controls across 19 sites participating in the ENIGMA-OCD Working Group. Main Outcomes and MeasuresWe extracted measures of fractional anisotropy (FA) as main outcome, and mean diffusivity, radial diffusivity, and axial diffusivity as secondary outcomes for 25 white matter regions. We meta-analyzed patient-control group differences (Cohens d) across sites, after adjusting for age and sex, and investigated associations with clinical characteristics. ResultsAdult OCD patients showed significant FA reduction in the sagittal stratum (d=-0.21, z=-3.21, p=0.001) and posterior thalamic radiation (d=-0.26, z=-4.57, p<0.0001). In the sagittal stratum only, lower FA was associated with a younger age of onset (z=2.71, p=0.006), longer duration of illness (z=-2.086, p=0.036) and a higher percentage of medicated patients in the cohorts studied (z=-1.98, p=0.047). No significant association with symptom severity was found. Pediatric OCD patients did not show any detectable microstructural abnormalities compared to matched controls. Conclusions and RelevanceMicrostructural alterations in projection and association fibers to posterior brain regions were found in adult OCD, and related to disease course and medication status. Such results are relevant to models positing deficits in connectivity as a crucial mechanism in OCD. KEY POINTSO_ST_ABSQuestionC_ST_ABSDo patients with Obsessive-Compulsive Disorder (OCD) show white matter microstructural alterations, and are these alterations related to clinical features? FindingsData from 19 sites of the ENIGMA-OCD Consortium were included, involving 700 adult patients and 645 adult controls, 174 pediatric patients and 144 pediatric controls. Diffusion tensor imaging data were meta-analyzed using a harmonized data processing and analysis protocol. Adult, but not pediatric, patients showed alterations in the sagittal stratum and posterior thalamic radiation; sagittal stratum differences were associated with clinical features. MeaningMicrostructural abnormalities found in adult but not in the pediatric cohort, are related to illness duration and medication status.

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bioRxiv2019

Childhood socio-economic disadvantage predicts reduced myelin growth across adolescence and young adulthood

Socio-economic disadvantage (SED) increases exposure to life stressors. Animal research suggests early life stressors affect later neurodevelopment, including myelin developmental growth. To determine whether human childhood SED affects myelination in adolescence and early adulthood we measured the developmental increase of a sensitive myelin marker, magnetization transfer (MT), in a longitudinal study. Childhood SED was associated with globally reduced MT, as well as slower intra-cortical MT increase in widespread sensory-motor, cingulate, insular and prefrontal areas and subcortical areas. Parental education partially accounted for the SED effects on MT increase, while positive parenting provided a partial protection against the impact of SED. Thus, early socio-economic disadvantage, a vulnerability factor for a range of ill-health outcomes, is a risk factor for aberrant myelin growth during a critical developmental period that is associated with a high risk of psychiatric disorder.

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bioRxiv2019

Hippocampal-midbrain circuit enhances the pleasure of anticipation in the prefrontal cortex

Having something to look forward to is a keystone of well-being. Anticipation of a future reward, like an upcoming vacation, can often be more gratifying than the very experience itself. Theories of anticipation have described how it induces behaviors ranging from beneficial information-seeking through to harmful addiction. However, it remains unclear how neural systems compute an attractive value from anticipation, instead of from the reward itself. To address this gap, we administered a decision-making task to human participants that allowed us to analyze brain activity during receipt of information predictive of future pleasant outcomes. Using a computational model of anticipatory value that captures participants decisions, we show that an anticipatory value signal is orchestrated by influences from three brain regions. Ventromedial prefrontal cortex (vmPFC) tracks the value of anticipation; dopaminergic midbrain responds to information that enhances anticipation, while sustained hippocampal activity provides a functional coupling between these regions. This coordinating function of the hippocampus is consistent with its known role in episodic future thinking. Our findings shed new light on the neural underpinnings of anticipations influence over decision-making, while also unifying a range of phenomena associated with risk and time-delay preference.

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bioRxiv2018

Noradrenaline modulates decision urgency during sequential information gathering

Arbitrating between timely choice and extended information gathering is critical in effective decision making. Aberrant information gathering behaviour is said to be a feature of psychiatric disorders such as schizophrenia and obsessive-compulsive disorder. We know little about the neurocognitive control mechanisms that drive such information gathering. In a double-blind placebo-controlled drug study with 60 healthy humans (30 female), we examined the effects of noradrenaline and dopamine antagonism on information gathering. We show that modulating noradrenaline function with propranolol leads to decreased information gathering behaviour and this contrasts with no effect following a modulation of dopamine function. Using a Bayesian computational model, we show sampling behaviour is best explained when including an urgency signal that promotes commitment to an early decision. We demonstrate that noradrenaline blockade promotes the expression of this decision-related urgency signal during information gathering. We discuss the findings with respect to psychopathological conditions that are linked to aberrant information gathering.\n\nSignificance StatementKnowing when to stop gathering information and commit to an option is non-trivial. This is an important element in arbitrating between information gain and energy conservation. In this double-blind, placebo-controlled drug study, we investigated to role of catecholamines noradrenaline and dopamine on sequential information gathering. We found that blocking noradrenaline led to a decrease in information gathering, with no effect seen following dopamine blockade. Using a Bayesian computational model, we show that this noradrenaline effect is driven by an increased decision urgency, a signal that reflects an escalating subjective cost of sampling. The observation that noradrenaline modulates decision urgency suggests new avenues for treating patients that show information gathering deficits.

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bioRxiv2017

Metacognitive impairments extend perceptual decision making weaknesses in compulsivity

Awareness of ones own abilities is of paramount importance in adaptive decision making. Psychotherapeutic theories assume such metacognitive insight is impaired in compulsivity, though this is supported by scant empirical evidence. In this study, we investigate metacognitive abilities in compulsive participants using computational models, where these enable a segregation between metacognitive and perceptual decision making impairments. We examined twenty low-compulsive and twenty high-compulsive participants, recruited from a large population-based sample, and matched for other psychiatric and cognitive dimensions. Hierarchical computational modelling of the participants metacognitive abilities on a visual global motion detection paradigm revealed that high-compulsive participants had a reduced metacognitive ability. This impairment was accompanied by a perceptual decision making deficit whereby motion-related evidence was accumulated more slowly in high compulsive participants. Our study shows that the compulsivity spectrum is associated with a reduced ability to monitor ones own performance, over and above any perceptual decision making difficulty.

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