30 research outputs found
Îases cĂ©rĂ©brales du compromis coĂ»ts/bĂ©nĂ©fices
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 dĂ©cisions sur les actions que nous souhaitons entreprendre. Ces dĂ©cisions se fondent sur un compromis entre les bĂ©nĂ©fices que nous espĂ©rons obtenir aprĂšs avoir effectuĂ© ces actions, et les coĂ»ts, en termes dâeffort, associĂ©s Ă ces actions. Cette thĂšse sâintĂ©resse aux bases cĂ©rĂ©brales du compromis coĂ»ts/bĂ©nĂ©fices au travers de trois Ă©tudes menĂ©es chez des participants sains Ă lâaide de lâimagerie par rĂ©sonance magnĂ©tique fonctionnelle. Dans la premiĂšre Ă©tude, nous avons pu dissocier les bases cĂ©rĂ©brales du calcul du compromis coĂ»ts/bĂ©nĂ©fices des bases cĂ©rĂ©brales des variables rĂ©gulant ce calcul. En effet, dans cette Ă©tude, le calcul du compromis coĂ»ts/bĂ©nĂ©fices Ă©tait associĂ© au cortex prĂ©frontal ventromĂ©dian alors que la confiance dans la dĂ©cision et le temps passĂ© Ă dĂ©libĂ©rer Ă©taient associĂ©s Ă des parties plus dorsales du cortex prĂ©frontal mĂ©dian. La seconde Ă©tude a permis de montrer que, dans deux tĂąches, impliquant un effort mental ou physique, la performance sâexpliquait mieux par un biais pavlovien, donnant plus de poids aux gains quâaux pertes, que par une aversion Ă la perte, telle quâelle a Ă©tĂ© caractĂ©risĂ©e principalement dans des tĂąches de choix. La troisiĂšme Ă©tude nous a permis de montrer que, mĂȘme dans une tĂąche simple dâapprentissage par renforcement, les aires cĂ©rĂ©brales liĂ©es Ă lâexĂ©cution dâun effort mental Ă©taient recrutĂ©es au moment du calcul du compromis coĂ»ts/bĂ©nĂ©fices, suggĂ©rant que cette tĂąche nâĂ©tait pas effectuĂ©e de maniĂšre purement automatique. Lâensemble de nos rĂ©sultats permet de mieux caractĂ©riser les aires cĂ©rĂ©brales impliquĂ©es dans le compromis coĂ»ts/bĂ©nĂ©fices et les conditions dans lesquelles ces aires sont actives
Neural correlates of the cost/benefit tradeoff
Tous les jours, nous prenons des dĂ©cisions sur les actions que nous souhaitons entreprendre. Ces dĂ©cisions se fondent sur un compromis entre les bĂ©nĂ©fices que nous espĂ©rons obtenir aprĂšs avoir effectuĂ© ces actions, et les coĂ»ts, en termes dâeffort, associĂ©s Ă ces actions. Cette thĂšse sâintĂ©resse aux bases cĂ©rĂ©brales du compromis coĂ»ts/bĂ©nĂ©fices au travers de trois Ă©tudes menĂ©es chez des participants sains Ă lâaide de lâimagerie par rĂ©sonance magnĂ©tique fonctionnelle. Dans la premiĂšre Ă©tude, nous avons pu dissocier les bases cĂ©rĂ©brales du calcul du compromis coĂ»ts/bĂ©nĂ©fices des bases cĂ©rĂ©brales des variables rĂ©gulant ce calcul. En effet, dans cette Ă©tude, le calcul du compromis coĂ»ts/bĂ©nĂ©fices Ă©tait associĂ© au cortex prĂ©frontal ventromĂ©dian alors que la confiance dans la dĂ©cision et le temps passĂ© Ă dĂ©libĂ©rer Ă©taient associĂ©s Ă des parties plus dorsales du cortex prĂ©frontal mĂ©dian. La seconde Ă©tude a permis de montrer que, dans deux tĂąches, impliquant un effort mental ou physique, la performance sâexpliquait mieux par un biais pavlovien, donnant plus de poids aux gains quâaux pertes, que par une aversion Ă la perte, telle quâelle a Ă©tĂ© caractĂ©risĂ©e principalement dans des tĂąches de choix. La troisiĂšme Ă©tude nous a permis de montrer que, mĂȘme dans une tĂąche simple dâapprentissage par renforcement, les aires cĂ©rĂ©brales liĂ©es Ă lâexĂ©cution dâun effort mental Ă©taient recrutĂ©es au moment du calcul du compromis coĂ»ts/bĂ©nĂ©fices, suggĂ©rant que cette tĂąche nâĂ©tait pas effectuĂ©e de maniĂšre purement automatique. Lâensemble de nos rĂ©sultats permet de mieux caractĂ©riser les aires cĂ©rĂ©brales impliquĂ©es dans le compromis coĂ»ts/bĂ©nĂ©fices 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
Español y qawasqar
Signo y Seña es la revista especializada del Instituto de LingĂŒĂstica de la Facultad de FilosofĂa y Letras de la Universidad de Buenos Aires. Convoca y estĂĄ destinada a investigadores del lenguaje formados y en formaciĂłn tanto de la Argentina como del exterior. Es una publicaciĂłn semestral electrĂłnica y de libre acceso que tiene como objetivo fundamental promover el debate, el intercambio de ideas y la difusiĂłn de investigaciones recientes de todas las ĂĄreas de la lingĂŒĂstica. Signo y Seña incluye en cada nĂșmero: una secciĂłn temĂĄtica o monogrĂĄfica a cargo de reconocidos especialistas en el ĂĄrea,una secciĂłn general de resultados investigaciones de todas las ĂĄreas de la LingĂŒĂstica y una secciĂłn de reseñas y novedades referentes a la disciplina. En sus pĂĄginas se publican trabajos originales e inĂ©ditos evaluados con el sistema de pares externos doble ciego en español y en portuguĂ©s.
José Emperaire et les Qawasqar. Notes linguistiques inédites sur Les Nomades de la Mer
Annette and JosĂ© Emperaire dedicated an important part of their life to the study of the culture of the indians of Patagonia and Tierra del Fuego. After living approximately two years with the Qawasqar of occidental Patagonia, also called Alakaluf, JosĂ© Emperaire gathered an important documentation about their life and their culture. His book Les Nomades de la Mer is devoted to them. One of his intentions was to publish a dictionary of their language which had been neglected by the linguists. Part of his original linguistic notes are published here, thanks to the generosity of Annette Laming-Emperaire. Without modifying anything, we simply added a phonologic notation for each term.Annette et JosĂ© Emperaire ont consacrĂ© une grande partie de leur vie Ă l'Ă©tude de la culture des indiens de la Patagonie et de la Terre de Feu. AprĂšs avoir vĂ©cu environ deux ans avec les Qawasqar de la Patagonie occidentale, connus aussi comme Alakaluf, JosĂ© Emperaire a recueilli une importante documentation sur leur vie et leur culture. Son livre Les Nomades de la Mer leur est consacrĂ©. Une de ses intentions Ă©tait de publier un dictionnaire de leur langue, nĂ©gligĂ©e Ă l'Ă©poque par les linguistes. On publie ici une partie de ses notes linguistiques inĂ©dites, grĂące Ă la gĂ©nĂ©rositĂ© d'Annette Laming-Emperaire. Sans rien modifier au texte original, nous avons simplement ajoutĂ© une notation phonologique pour chaque terme.Annette y JosĂ© Emperaire dedicaron una importante parte de su vida al estudio de la cultura de los indĂgenas de Patagonia y Tierra del Fuego. DespuĂ©s de convivir aproximada- mente durante dos aĆos. con los Qawasqar de Patagonia occidental, llamados tambiĂ©n Alakaluf, JosĂ© Emperaire recogiĂł una documentacion importante sobre su vida y cultura. Su libro "Les Nomades de la Mer" esta consagrado a ellos. Una de sus intenciones fue publicar un diccionario de su idioma, descuidado en aquel tiempo por los linguĂstas. Una parte de sus notas lingĂŒisticas inĂ©ditas se publican aquĂ gracias a la generosidad de Annette Laming-Emperaire. Sin modificar el texto original, hemos aĆadido solamente una notation fonolĂłgica para cada tĂ©rmino.Clairis Christos. JosĂ© Emperaire et les Qawasqar. Notes linguistiques inĂ©dites sur Les Nomades de la Mer. In: Journal de la SociĂ©tĂ© des AmĂ©ricanistes. Tome 67, 1980. pp. 359-382
Îases cĂ©rĂ©brales du compromis coĂ»ts/bĂ©nĂ©fices
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 dĂ©cisions sur les actions que nous souhaitons entreprendre. Ces dĂ©cisions se fondent sur un compromis entre les bĂ©nĂ©fices que nous espĂ©rons obtenir aprĂšs avoir effectuĂ© ces actions, et les coĂ»ts, en termes dâeffort, associĂ©s Ă ces actions. Cette thĂšse sâintĂ©resse aux bases cĂ©rĂ©brales du compromis coĂ»ts/bĂ©nĂ©fices au travers de trois Ă©tudes menĂ©es chez des participants sains Ă lâaide de lâimagerie par rĂ©sonance magnĂ©tique fonctionnelle. Dans la premiĂšre Ă©tude, nous avons pu dissocier les bases cĂ©rĂ©brales du calcul du compromis coĂ»ts/bĂ©nĂ©fices des bases cĂ©rĂ©brales des variables rĂ©gulant ce calcul. En effet, dans cette Ă©tude, le calcul du compromis coĂ»ts/bĂ©nĂ©fices Ă©tait associĂ© au cortex prĂ©frontal ventromĂ©dian alors que la confiance dans la dĂ©cision et le temps passĂ© Ă dĂ©libĂ©rer Ă©taient associĂ©s Ă des parties plus dorsales du cortex prĂ©frontal mĂ©dian. La seconde Ă©tude a permis de montrer que, dans deux tĂąches, impliquant un effort mental ou physique, la performance sâexpliquait mieux par un biais pavlovien, donnant plus de poids aux gains quâaux pertes, que par une aversion Ă la perte, telle quâelle a Ă©tĂ© caractĂ©risĂ©e principalement dans des tĂąches de choix. La troisiĂšme Ă©tude nous a permis de montrer que, mĂȘme dans une tĂąche simple dâapprentissage par renforcement, les aires cĂ©rĂ©brales liĂ©es Ă lâexĂ©cution dâun effort mental Ă©taient recrutĂ©es au moment du calcul du compromis coĂ»ts/bĂ©nĂ©fices, suggĂ©rant que cette tĂąche nâĂ©tait pas effectuĂ©e de maniĂšre purement automatique. Lâensemble de nos rĂ©sultats permet de mieux caractĂ©riser les aires cĂ©rĂ©brales impliquĂ©es dans le compromis coĂ»ts/bĂ©nĂ©fices et les conditions dans lesquelles ces aires sont actives