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Every day we make decisions about the actions we want to perform. These decisions are based on a trade-off between the benefits we hope to obtain from performing these actions, and the costs, in terms of effort, associated with those actions. This thesis examines the neural correlates of the cost/benefit trade-off through three studies conducted in healthy participants using functional magnetic resonance imaging. In the first study, we were able to dissociate the neural correlates of the computation of the cost/benefit trade-off from the neural correlates of the variables regulating this computation. Indeed, in this study, the computation of the cost/benefit trade-off was associated with the ventromedial prefrontal cortex, whereas confidence in the decision and the time spent in deliberating were associated with more dorsal parts of the medial prefrontal cortex. With our second study, we observed that, in two tasks, involving a mental or a physical effort, the performance was better explained by a Pavlovian bias than by loss aversion. In other words, as opposed to what has been shown mainly in choice tasks, individuals tended to give more weight to gains than to losses. The third study allowed us to show that, even in a simple reinforcement learning task, the brain areas linked to the exertion of a mental effort were recruited while the cost/benefit trade-off was being computed, suggesting that this task was not carried out purely automatically. All these results allow us to better characterize the brain areas involved in the cost/benefit trade-off and the conditions in which these areas are active., Tous les jours, nous prenons des décisions sur les actions que nous souhaitons entreprendre. Ces décisions se fondent sur un compromis entre les bénéfices que nous espérons obtenir après avoir effectué ces actions, et les coûts, en termes d’effort, associés à ces actions. Cette thèse s’intéresse aux bases cérébrales du compromis coûts/bénéfices au travers de trois études menées chez des participants sains à l’aide de l’imagerie par résonance magnétique fonctionnelle. Dans la première étude, nous avons pu dissocier les bases cérébrales du calcul du compromis coûts/bénéfices des bases cérébrales des variables régulant ce calcul. En effet, dans cette étude, le calcul du compromis coûts/bénéfices était associé au cortex préfrontal ventromédian alors que la confiance dans la décision et le temps passé à délibérer étaient associés à des parties plus dorsales du cortex préfrontal médian. La seconde étude a permis de montrer que, dans deux tâches, impliquant un effort mental ou physique, la performance s’expliquait mieux par un biais pavlovien, donnant plus de poids aux gains qu’aux pertes, que par une aversion à la perte, telle qu’elle a été caractérisée principalement dans des tâches de choix. La troisième étude nous a permis de montrer que, même dans une tâche simple d’apprentissage par renforcement, les aires cérébrales liées à l’exécution d’un effort mental étaient recrutées au moment du calcul du compromis coûts/bénéfices, suggérant que cette tâche n’était pas effectuée de manière purement automatique. L’ensemble de nos résultats permet de mieux caractériser les aires cérébrales impliquées dans le compromis coûts/bénéfices et les conditions dans lesquelles ces aires sont actives.

Every day we make decisions about the actions we want to perform. These decisions are based on a trade-off between the benefits we hope to obtain from performing these actions, and the costs, in terms of effort, associated with those actions. This thesis examines the neural correlates of the cost/benefit trade-off through three studies conducted in healthy participants using functional magnetic resonance imaging. In the first study, we were able to dissociate the neural correlates of the computation of the cost/benefit trade-off from the neural correlates of the variables regulating this computation. Indeed, in this study, the computation of the cost/benefit trade-off was associated with the ventromedial prefrontal cortex, whereas confidence in the decision and the time spent in deliberating were associated with more dorsal parts of the medial prefrontal cortex. With our second study, we observed that, in two tasks, involving a mental or a physical effort, the performance was better explained by a Pavlovian bias than by loss aversion. In other words, as opposed to what has been shown mainly in choice tasks, individuals tended to give more weight to gains than to losses. The third study allowed us to show that, even in a simple reinforcement learning task, the brain areas linked to the exertion of a mental effort were recruited while the cost/benefit trade-off was being computed, suggesting that this task was not carried out purely automatically. All these results allow us to better characterize the brain areas involved in the cost/benefit trade-off and the conditions in which these areas are active., Tous les jours, nous prenons des décisions sur les actions que nous souhaitons entreprendre. Ces décisions se fondent sur un compromis entre les bénéfices que nous espérons obtenir après avoir effectué ces actions, et les coûts, en termes d’effort, associés à ces actions. Cette thèse s’intéresse aux bases cérébrales du compromis coûts/bénéfices au travers de trois études menées chez des participants sains à l’aide de l’imagerie par résonance magnétique fonctionnelle. Dans la première étude, nous avons pu dissocier les bases cérébrales du calcul du compromis coûts/bénéfices des bases cérébrales des variables régulant ce calcul. En effet, dans cette étude, le calcul du compromis coûts/bénéfices était associé au cortex préfrontal ventromédian alors que la confiance dans la décision et le temps passé à délibérer étaient associés à des parties plus dorsales du cortex préfrontal médian. La seconde étude a permis de montrer que, dans deux tâches, impliquant un effort mental ou physique, la performance s’expliquait mieux par un biais pavlovien, donnant plus de poids aux gains qu’aux pertes, que par une aversion à la perte, telle qu’elle a été caractérisée principalement dans des tâches de choix. La troisième étude nous a permis de montrer que, même dans une tâche simple d’apprentissage par renforcement, les aires cérébrales liées à l’exécution d’un effort mental étaient recrutées au moment du calcul du compromis coûts/bénéfices, suggérant que cette tâche n’était pas effectuée de manière purement automatique. L’ensemble de nos résultats permet de mieux caractériser les aires cérébrales impliquées dans le compromis coûts/bénéfices et les conditions dans lesquelles ces aires sont actives.

We present an extension of the Individual Brain Charting dataset –a high spatial-resolution, multi-task, functional Magnetic Resonance Imaging dataset, intended to support the investigation on the functional principles governing cognition in the human brain. The concomitant data acquisition from the same 12 participants, in the same environment, allows to obtain in the long run finer cognitive topographies, free from inter-subject and inter-site variability. This second release provides more data from psychological domains present in the first release, and also yields data featuring new ones. It includes tasks on e.g. mental time travel, reward, theory-of-mind, pain, numerosity, self-reference effect and speech recognition. In total, 13 tasks with 86 contrasts were added to the dataset and 63 new components were included in the cognitive description of the ensuing contrasts. As the dataset becomes larger, the collection of the corresponding topographies becomes more comprehensive, leading to better brain-atlasing frameworks. This dataset is an open-access facility; raw data and derivatives are publicly available in neuroimaging repositories., Measurement(s) functional brain measurement • regional part of brain • brain measurement • cognition Technology Type(s) functional magnetic resonance imaging Factor Type(s) type of task Sample Characteristic - Organism Homo sapiens Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12958181

Deciding about courses of action involves minimizing costs and maximizing benefits. Decision neuroscience studies have implicated both the ventral and dorsal medial PFC (vmPFC and dmPFC) in signaling goal value and action cost, but the precise functional role of these regions is still a matter of debate. Here, we suggest a more general functional partition that applies not only to decisions but also to judgments about goal value (expected reward) and action cost (expected effort). In this conceptual framework, cognitive representations related to options (reward value and effort cost) are dissociated from metacognitive representations (confidence and deliberation) related to solving the task (providing a judgment or making a choice). We used an original approach aimed at identifying consistencies across several preference tasks, from likeability ratings to binary decisions involving both attribute integration and option comparison. fMRI results in human male and female participants confirmed the vmPFC as a generic valuation system, its activity increasing with reward value and decreasing with effort cost. In contrast, more dorsal regions were not concerned with the valuation of options but with metacognitive variables, confidence being reflected in mPFC activity and deliberation time in dmPFC activity. Thus, there was a dissociation between the effort attached to choice options (represented in the vmPFC) and the effort invested in deliberation (represented in the dmPFC), the latter being expressed in pupil dilation. More generally, assessing commonalities across preference tasks might help in reaching a unified view of the neural mechanisms underlying the cost/benefit tradeoffs that drive human behavior. SIGNIFICANCE STATEMENT Decision neuroscience studies have implicated the medial PFC in forming the cognitive representations that drive human choice behavior. However, different studies using different tasks have suggested somewhat inconsistent links between precise computational variables and specific brain regions. Here, we use fMRI to demonstrate a robust functional partition of the medial PFC that generalizes across tasks involving an estimation of goal value and/or action cost to provide a judgment or make a choice. This general functional partition makes a critical dissociation between neural representations of decisional factors (the expected costs and benefits attached to a given option) and metacognitive estimates (confidence in the judgment or choice, and effort invested in the deliberation process).