Publications des chercheurs de PSE

Affichage des résultats 1 à 12 sur 15 au total.

  • How large is "large enough" ? Large-scale experimental investigation of the reliability of confidence measures Pré-publication, Document de travail:

    Whether individuals feel confident about their own actions, choices, or statements being correct, and how these confidence levels differ between individuals are two key primitives for countless behavioral theories and phenomena. In cognitive tasks, individual confidence is typically measured as the average of reports about choice accuracy, but how reliable is the resulting characterization of within-and between-individual confidence remains surprisingly undocumented. Here, we perform a large-scale resampling exercise in the Confidence Database to investigate the reliability of individual confidence estimates, and of comparisons across individuals' confidence levels. Our results show that confidence estimates are more stable than their choice-accuracy counterpart, reaching a reliability plateau after roughly 50 trials, regardless of a number of task design characteristics. While constituting a reliability upper-bound for task-based confidence measures, and thereby leaving open the question of the reliability of the construct itself, these results characterize the robustness of past and future task designs.

    Auteur(s) : Nicolas Jacquemet, Maël Lebreton

    Publié en

  • Anticipatory Anxiety and Wishful Thinking Article dans une revue:

    Across five experiments (N = 1,714), we test whether people engage in wishful thinking to alleviate anxiety about adverse future outcomes. Participants perform pattern recognition tasks in which some patterns may result in an electric shock or a monetary loss. Diagnostic of wishful thinking, participants are less likely to correctly identify patterns that are associated with a shock or loss. Wishful thinking is more pronounced under more ambiguous signals and only reduced by higher accuracy incentives when participants’ cognitive effort reduces ambiguity. Wishful thinking disappears in the domain of monetary gains, indicating that negative emotions are important drivers of the phenomenon.

    Auteur(s) : Maël Lebreton Revue : American Economic Review

    Publié en

  • Specificity and sensitivity of the fixed-point test for binary mixture distributions Article dans une revue:

    When two cognitive processes contribute to a behavioral output—each process producing a specific distribution of the behavioral variable of interest—and when the mixture proportion of these two processes varies as a function of an experimental condition, a common density point should be present in the observed distributions of the data across said conditions. In principle, one can statistically test for the presence (or absence) of a fixed point in experimental data to provide evidence in favor of (or against) the presence of a mixture of processes, whose proportions are affected by an experimental manipulation. In this paper, we provide an empirical diagnostic of this test to detect a mixture of processes. We do so using resampling of real experimental data under different scenarios, which mimic variations in the experimental design suspected to affect the sensitivity and specificity of the fixed-point test (i.e., mixture proportion, time on task, and sample size). Resampling such scenarios with real data allows us to preserve important features of data which are typically observed in real experiments while maintaining tight control over the properties of the resampled scenarios. This is of particular relevance considering such stringent assumptions underlying the fixed-point test. With this paper, we ultimately aim at validating the fixed-point property of binary mixture data and at providing some performance metrics to researchers aiming at testing the fixed-point property on their experimental data.

    Auteur(s) : Maël Lebreton Revue : Behavior Research Methods

    Publié en

  • Experiential values are underweighted in decisions involving symbolic options Article dans une revue:

    Standard models of decision-making assume each option is associated with subjective value, regardless of whether this value is inferred from experience (experiential) or explicitly instructed probabilistic outcomes (symbolic). In this study, we present results that challenge the assumption of unified representation of experiential and symbolic value. Across nine experiments, we presented participants with hybrid decisions between experiential and symbolic options. Participants’ choices exhibited a pattern consistent with a systematic neglect of the experiential values. This normatively irrational decision strategy held after accounting for alternative explanations, and persisted even when it bore an economic cost. Overall, our results demonstrate that experiential and symbolic values are not symmetrically considered in hybrid decisions, suggesting they recruit different representational systems that may be assigned different priority levels in the decision process. These findings challenge the dominant models commonly used in value-based decision-making research.

    Auteur(s) : Maël Lebreton Revue : Nature Human Behaviour

    Publié en

  • Neural and computational underpinnings of biased confidence in human reinforcement learning Article dans une revue:

    While navigating a fundamentally uncertain world, humans and animals constantly evaluate the probability of their decisions, actions or statements being correct. When explicitly elicited, these confidence estimates typically correlates positively with neural activity in a ventromedial-prefrontal (VMPFC) network and negatively in a dorsolateral and dorsomedial prefrontal network. Here, combining fMRI with a reinforcement-learning paradigm, we leverage the fact that humans are more confident in their choices when seeking gains than avoiding losses to reveal a functional dissociation: whereas the dorsal prefrontal network correlates negatively with a condition-specific confidence signal, the VMPFC network positively encodes task-wide confidence signal incorporating the valence-induced bias. Challenging dominant neuro-computational models, we found that decision-related VMPFC activity better correlates with confidence than with option-values inferred from reinforcement-learning models. Altogether, these results identify the VMPFC as a key node in the neuro-computational architecture that builds global feeling-of-confidence signals from latent decision variables and contextual biases during reinforcement-learning.

    Auteur(s) : Maël Lebreton Revue : Nature Communications

    Publié en

  • A shared brain system forming confidence judgment across cognitive domains Article dans une revue:

    Confidence is typically defined as a subjective judgment about whether a decision is right. Decisions are based on sources of information that come from various cognitive domains and are processed in different brain systems. An unsettled question is whether the brain computes confidence in a similar manner whatever the domain or in a manner that would be idiosyncratic to each domain. To address this issue, human participants performed two tasks probing confidence in decisions made about the same material (history and geography statements), but based on different cognitive processes: semantic memory for deciding whether the statement was true or false, and duration perception for deciding whether the statement display was long or short. At the behavioral level, we found that the same factors (difficulty, accuracy, response time, and confidence in the preceding decision) predicted confidence judgments in both tasks. At the neural level, we observed using functional magnetic resonance imaging that confidence judgments in both tasks were associated to activity in the same brain regions: positively in the ventromedial prefrontal cortex and negatively in a prefronto-parietal network. Together, these findings suggest the existence of a shared brain system that generates confidence judgments in a similar manner across cognitive domains.

    Auteur(s) : Maël Lebreton Revue : Cerebral Cortex

    Publié en

  • Learning rules of engagement for social exchange within and between groups Article dans une revue:

    Globalizing economies and long-distance trade rely on individuals from different cultural groups to negotiate agreement on what to give and take. In such settings, individuals often lack insight into what interaction partners deem fair and appropriate, potentially seeding misunderstandings, frustration, and conflict. Here, we examine how individuals decipher distinct rules of engagement and adapt their behavior to reach agreements with partners from other cultural groups. Modeling individuals as Bayesian learners with inequality aversion reveals that individuals, in repeated ultimatum bargaining with responders sampled from different groups, can be more generous than needed. While this allows them to reach agreements, it also gives rise to biased beliefs about what is required to reach agreement with members from distinct groups. Preregistered behavioral ( N = 420) and neuroimaging experiments ( N = 49) support model predictions: Seeking equitable agreements can lead to overly generous behavior toward partners from different groups alongside incorrect beliefs about prevailing norms of what is appropriate in groups and cultures other than one’s own.

    Auteur(s) : Maël Lebreton Revue : Proceedings of the National Academy of Sciences of the United States of America

    Publié en

  • Linking confidence biases to reinforcement-learning processes. Article dans une revue:

    We systematically misjudge our own performance in simple economic tasks. First, we generally overestimate our ability to make correct choices-a bias called overconfidence. Second, we are more confident in our choices when we seek gains than when we try to avoid losses-a bias we refer to as the valence-induced confidence bias. Strikingly, these two biases are also present in reinforcement-learning (RL) contexts, despite the fact that outcomes are provided trial-by-trial and could, in principle, be used to recalibrate confidence judgments online. How confidence biases emerge and are maintained in reinforcement-learning contexts is thus puzzling and still unaccounted for. To explain this paradox, we propose that confidence biases stem from learning biases, and test this hypothesis using data from multiple experiments, where we concomitantly assessed instrumental choices and confidence judgments, during learning and transfer phases. Our results first show that participants' choices in both tasks are best accounted for by a reinforcement-learning model featuring context-dependent learning and confirmatory updating. We then demonstrate that the complex, biased pattern of confidence judgments elicited during both tasks can be explained by an overweighting of the learned value of the chosen option in the computation of confidence judgments. We finally show that, consequently, the individual learning model parameters responsible for the learning biases-confirmatory updating and outcome context-dependency-are predictive of the individual metacognitive biases. We conclude suggesting that the metacognitive biases originate from fundamentally biased learning computations.

    Auteur(s) : Maël Lebreton Revue : Psychological Review

    Publié en

  • Decision-making under risk and ambiguity in adults with Tourette syndrome Article dans une revue:

    Background Tourette syndrome (TS) as well as its most common comorbidities are associated with a higher propensity for risky behaviour in everyday life. However, it is unclear whether this increased risk propensity in real-life contexts translates into a generally increased attitude towards risk. We aimed to assess decision-making under risk and ambiguity based on prospect theory by considering the effects of comorbidities and medication. Methods Fifty-four individuals with TS and 32 healthy controls performed risk and ambiguity decision-making tasks under both gains and losses conditions. Behavioural and computational parameters were evaluated using (i) univariate analysis to determine parameters difference taking independently; (ii) supervised multivariate analysis to evaluate whether our parameters could jointly account for between-group differences (iii) unsupervised multivariate analysis to explore the potential presence of sub-groups. Results Except for general ‘noisier’ (less consistent) decisions in TS, we showed no specific risk-taking behaviour in TS or any relation with tics severity or antipsychotic medication. However, the presence of comorbidities was associated with distortion of decision-making. Specifically, TS with obsessive–compulsive disorder comorbidity was associated with a higher risk-taking profile to increase gain and a higher risk-averse profile to decrease loss. TS with attention-deficit hyperactivity disorder comorbidity was associated with risk-seeking in the ambiguity context to reduce a potential loss. Conclusions Impaired valuation of risk and ambiguity was not related to TS per se . Our findings are important for clinical practice: the involvement of individuals with TS in real-life risky situations may actually rather result from other factors such as psychiatric comorbidities.

    Auteur(s) : Maël Lebreton Revue : Psychological Medicine

    Publié en

  • The impassable gap between experiential and symbolic values Article dans une revue:

    To choose between options of different natures, standard decision models presume that a single representational system ultimately indexes their subjective value on a common scale, regardless of how they are constructed. To challenge this assumption, we systematically investigated hybrid decisions between experiential options, whose value is built from past outcomes experience, and symbolic options which describe probabilistic outcomes. We show that participants' choices exhibited a pattern consistent with a systematic neglect of the experiential values. This normatively irrational decision strategy held after accounting for alternative explanations, and persisted when it bore an economics cost. Overall, our results demonstrate that experiential and symbolic values are not symmetrically considered in hybrid decisions, suggesting that they are not commensurable and recruit different representational systems which may be assigned different priority levels in the decision process. These findings challenge the dominant models commonly used in value-based decision-making research.

    Auteur(s) : Maël Lebreton Revue : Nature Human Behaviour

    Publié en

  • The computational roots of positivity and confirmation biases in reinforcement learning Article dans une revue:

    Humans do not integrate new information objectively: outcomes carrying a positive affective value and evidence confirming one's own prior belief are overweighed. Until recently, theoretical and empirical accounts of the positivity and confirmation biases assumed them to be specific to 'high-level' belief updates. We present evidence against this account. Learning rates in reinforcement learning (RL) tasks, estimated across different contexts and species, generally present the same characteristic asymmetry, suggesting that belief and value updating processes share key computational principles and distortions. This bias generates over-optimistic expectations about the probability of making the right choices and, consequently, generates over-optimistic reward expectations. We discuss the normative and neurobiological roots of these RL biases and their position within the greater picture of behavioral decision-making theories.

    Auteur(s) : Maël Lebreton Revue : Trends in Cognitive Sciences

    Publié en

  • Metacognition and the effect of incentive motivation in two compulsive disorders: Gambling disorder and obsessive–compulsive disorder Article dans une revue:

    Aims Compulsivity is a common phenotype among psychiatric disorders, such as obsessive–compulsive disorder (OCD) and gambling disorder (GD). Deficiencies in metacognition, such as the inability to estimate one's performance via confidence judgments could contribute to pathological decision‐making. Earlier research has shown that patients with OCD exhibit underconfidence, while patients with GD exhibit overconfidence. Moreover, it is known that motivational states (e.g. monetary incentives) influence metacognition, with gain (respectively loss) prospects increasing (respectively decreasing) confidence. Here, we reasoned that OCD and GD symptoms might correspond to an exacerbation of this interaction between metacognition and motivation. Methods We hypothesized GD's overconfidence to be exaggerated during gain prospects, while OCD's underconfidence to be worsened in loss context, which we expected to see represented in ventromedial prefrontal cortex (VMPFC) blood‐oxygen‐level‐dependent activity. We tested those hypotheses in a task‐based functional magnetic resonance imaging (fMRI) design (27 patients with GD, 28 patients with OCD, 55 controls). The trial is registered in the Dutch Trial Register (NL6171). Results We showed increased confidence for patients with GD versus patients with OCD, which could partly be explained by sex and IQ. Although our primary analyses did not support the hypothesized interaction between incentives and groups, exploratory analyses did show increased confidence in patients with GD specifically in gain context. fMRI analyses confirmed a central role for VMPFC in the processing of confidence and incentives, but no differences between the groups. Conclusion Patients with OCD and those with GD reside at opposite ends of the confidence spectrum, while no interaction with incentives was found, nor group differences in neuronal processing of confidence.

    Auteur(s) : Maël Lebreton Revue : Psychiatry and Clinical Neurosciences

    Publié en