28 research outputs found

    Modeling choice and reaction time during arbitrary visuomotor learning through the coordination of adaptive working memory and reinforcement learning

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    International audienceCurrent learning theory provides a comprehensive description of how humans and other animals learn, and places behavioral flexibility and automaticity at heart of adaptive behaviors. However, the computations supporting the interactions between goal-directed and habitual decision-making systems are still poorly understood. Previous functional magnetic resonance imaging (fMRI) results suggest that the brain hosts complementary computations that may differentially support goal-directed and habitual processes in the form of a dynamical interplay rather than a serial recruitment of strategies. To better elucidate the computations underlying flexible behavior, we develop a dual-system computational model that can predict both performance (i.e., participants' choices) and modulations in reaction times during learning of a stimulus–response association task. The habitual system is modeled with a simple Q-Learning algorithm (QL). For the goal-directed system, we propose a new Bayesian Working Memory (BWM) model that searches for information in the history of previous trials in order to minimize Shannon entropy. We propose a model for QL and BWM coordination such that the expensive memory manipulation is under control of, among others, the level of convergence of the habitual learning. We test the ability of QL or BWM alone to explain human behavior, and compare them with the performance of model combinations, to highlight the need for such combinations to explain behavior. Two of the tested combination models are derived from the literature, and the latter being our new proposal. In conclusion, all subjects were better explained by model combinations, and the majority of them are explained by our new coordination proposal

    Abstracts of the 2014 Brains, Minds, and Machines Summer School

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    A compilation of abstracts from the student projects of the 2014 Brains, Minds, and Machines Summer School, held at Woods Hole Marine Biological Lab, May 29 - June 12, 2014.This work was supported by the Center for Brains, Minds and Machines (CBMM), funded by NSF STC award CCF-1231216

    Sustainable computational science: the ReScience initiative

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    Computer science o ers a large set of tools for prototyping, writing, running, testing, validating, sharing and reproducing results, however computational science lags behind. In the best case, authors may provide their source code as a compressed archive and they may feel con dent their research is reproducible. But this is not exactly true. Jonathan Buckheit and David Donoho proposed more than two decades ago that an article about computational results is advertising, not scholarship. e actual scholarship is the full so ware environment, code, and data that produced the result. is implies new work ows, in particular in peer-reviews. Existing journals have been slow to adapt: source codes are rarely requested, hardly ever actually executed to check that they produce the results advertised in the article. ReScience is a peer-reviewed journal that targets computational research and encourages the explicit replication of already published research, promoting new and open-source implementations in order to ensure that the original research can be replicated from its description. To achieve this goal, the whole publishing chain is radically di erent from other traditional scienti c journals. ReScience resides on GitHub where each new implementation of a computational study is made available together with comments, explanations, and so ware tests

    Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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    Contains fulltext : 172380.pdf (publisher's version ) (Open Access

    Coordination de systèmes de mémoire : modèles théoriques du comportement animal et humain

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    During this PhD funded by the B2V Memories Observatory, we performed a mathematical modeling of behavior in three distinct tasks (with human subjects, monkeys and rodents), all involving coordination between memory systems. In the first experiment, we reproduced the behavior of human subjects (choice and reaction time) by combining the mathematical models of working memory and procedural memory. For each subject, we associated their behavior to the best possible model by comparing generic models of coordination of these two memories from the current literature as well as our own proposal of a dynamic interaction between memories. In the end, it was our proposal of an interaction instead of a strict separation which proved most effective in the majority of cases to explain the behavior of the subjects. In a second experiment, the same coordination models were tested in a monkey task. Considered as a transferability test, this experiment mainly demonstrates the need for coordination of memories to explain the behavior of certain monkeys. In a third experiment, we modeled the behavior of a group of mice confronted with the learning of a motor action sequence in a labyrinth without visual cues. Comparing with two other learning strategies (path integration and graph planning), the combination of an episodic memory with a procedural memory proved to be the best model to reproduce the behavior of mice.Durant ce doctorat financé par l'observatoire B2V des mémoires, nous avons réalisé une modélisation mathématique du comportement dans trois tâches distinctes (avec des sujets humains, des sujets singes et des rongeurs), mais qui supposent toutes une coordination entre systèmes de mémoire. Dans la première expérience, nous avons reproduit le comportement de sujets humains (choix et temps de réaction) en combinant les modèles mathématiques d'une mémoire de travail et d'une mémoire inflexible. Nous avons associé pour un sujet son comportement au meilleur modèle possible en comparant des modèles génériques de coordination de ces deux mémoires issues de la littérature actuelle ainsi que notre propre proposition d'une interaction dynamique entre les mémoires. Au final, c'est notre proposition d'une interaction au lieu d'une séparation stricte qui s'est avérée la plus efficace dans la majorité des cas pour expliquer le comportement des sujets. Dans une deuxième expérience, les mêmes modèles de coordination ont été testés dans une tâche chez le singe. Considérée comme un test de transférabilité, cette expérience démontre principalement la nécessité de coordination de mémoires pour expliquer le comportement de certains singes. Dans une troisième expérience, nous avons modélisé le comportement d'un groupe de souris confronté à l'apprentissage d'une séquence d'action motrice dans un labyrinthe sans indices externes. En comparant avec deux autres stratégies d'apprentissages (intégration de chemin et planification dans un graphe), la combinaison d'une mémoire épisodique avec une mémoire inflexible s'est révélée être le meilleur modèle pour reproduire le comportement des souris

    Pynapple-files

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    NWB files to be used for the pynapple and GLM package documentatio

    Coordination of memory systems : theoretical models of human and animals behavior

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    Durant ce doctorat financé par l'observatoire B2V des mémoires, nous avons réalisé une modélisation mathématique du comportement dans trois tâches distinctes (avec des sujets humains, des sujets singes et des rongeurs), mais qui supposent toutes une coordination entre systèmes de mémoire. Dans la première expérience, nous avons reproduit le comportement de sujets humains (choix et temps de réaction) en combinant les modèles mathématiques d'une mémoire de travail et d'une mémoire inflexible. Nous avons associé pour un sujet son comportement au meilleur modèle possible en comparant des modèles génériques de coordination de ces deux mémoires issues de la littérature actuelle ainsi que notre propre proposition d'une interaction dynamique entre les mémoires. Au final, c'est notre proposition d'une interaction au lieu d'une séparation stricte qui s'est avérée la plus efficace dans la majorité des cas pour expliquer le comportement des sujets. Dans une deuxième expérience, les mêmes modèles de coordination ont été testés dans une tâche chez le singe. Considérée comme un test de transférabilité, cette expérience démontre principalement la nécessité de coordination de mémoires pour expliquer le comportement de certains singes. Dans une troisième expérience, nous avons modélisé le comportement d'un groupe de souris confronté à l'apprentissage d'une séquence d'action motrice dans un labyrinthe sans indices externes. En comparant avec deux autres stratégies d'apprentissages (intégration de chemin et planification dans un graphe), la combinaison d'une mémoire épisodique avec une mémoire inflexible s'est révélée être le meilleur modèle pour reproduire le comportement des souris.During this PhD funded by the B2V Memories Observatory, we performed a mathematical modeling of behavior in three distinct tasks (with human subjects, monkeys and rodents), all involving coordination between memory systems. In the first experiment, we reproduced the behavior of human subjects (choice and reaction time) by combining the mathematical models of working memory and procedural memory. For each subject, we associated their behavior to the best possible model by comparing generic models of coordination of these two memories from the current literature as well as our own proposal of a dynamic interaction between memories. In the end, it was our proposal of an interaction instead of a strict separation which proved most effective in the majority of cases to explain the behavior of the subjects. In a second experiment, the same coordination models were tested in a monkey task. Considered as a transferability test, this experiment mainly demonstrates the need for coordination of memories to explain the behavior of certain monkeys. In a third experiment, we modeled the behavior of a group of mice confronted with the learning of a motor action sequence in a labyrinth without visual cues. Comparing with two other learning strategies (path integration and graph planning), the combination of an episodic memory with a procedural memory proved to be the best model to reproduce the behavior of mice

    NeMoS Tutorial

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    Collection of datasets for NeMoS tutorial (https://nemos.readthedocs.io/en/latest/

    Adaptive coordination of working-memory and reinforcement learning in non-human primates performing a trial-and-error problem solving task

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    International audienceAccumulating evidence suggest that human behavior in trial-and-error learning tasks based on decisions between discrete actions may involve a combination of reinforcement learning (RL) and working-memory (WM). While the understanding of brain activity at stake in this type of tasks often involve the comparison with non-human primate neurophysiological results, it is not clear whether monkeys use similar combined RL and WM processes to solve these tasks. Here we analyzed the behavior of five monkeys with computational models combining RL and WM. Our model-based analysis approach enables to not only fit trial-by-trial choices but also transient slowdowns in reaction times, indicative of WM use. We found that the behavior of the five monkeys was better explained in terms of a combination of RL and WM despite inter-individual differences. The same coordination dynamics we used in a previous study in humans best explained the behavior of some monkeys while the behavior of others showed the opposite pattern, revealing a possible different dynamics of WM process. We further analyzed different variants of the tested models to open a discussion on how the long pretraining in these tasks may have favored particular coordination dynamics between RL and WM. This points towards either inter-species differences or protocol differences which could be further tested in humans
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