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Reliability of online visual and proprioceptive feedback: impact on learning and sensorimotor coding
No full textInternational audienceMultisensory integration is essential for learning and sensorimotor coding, facilitating learners' adaptation to environmental changes. Recent findings confirm that introducing unreliability into visual feedback enhances the use of motor coding, probably because proprioceptive cues are given greater weight. The present study was designed to test this hypothesis and, more generally, to explore the impact of visual versus proprioceptive cue reliability on learning processes. Participants performed a 12-target pointing sequence 100 times with different combinations of visual and proprioceptive feedback: reliable versus unreliable. Retention tests and intermanual transfer tests were administered 24 hours later. Results showed that learning and sensorimotor coding were both affected by the different combinations of visual and proprioceptive cue reliability. Fully reliable feedback allowed for the best retention, while fully unreliable feedback resulted in the worst retention. Visual reliability alone mediated the level of visuospatial coding performance in visuospatial transfer, regardless of the level of proprioceptive reliability, and conversely, reliable proprioception combined with unreliable vision provided the optimum sensory environment for motor coding in the motor transfer test.Overall, our study highlighted the essential role of both visual cue reliability and proprioceptive cue reliability -and their interactions-in motor learning and its generalization
Sur la complexité des jugements métacognitifs de la mémoire : preuves de la confiance rétrospective, du sentiment de savoir et des adultes âgés
No full textInternational audienceDissociations in types of memory tasks emerge when comparing feeling-of-knowing (FOK) judgments, predictions of upcoming performance, and retrospective confidence. This pattern has been used to construct theories of metacognitive access to memory, particularly in memory-impaired groups. In particular, older adults’ metacognitive sensitivity appears to vary between episodic (impaired) and semantic (intact) memory. However, this could be explained by the limitations of metacognitive measures and/or memory differences. We aimed to test these dissociations of metacognition with aging by comparing metacognitive efficiency in episodic and semantic tasks using two types of judgment: retrospective confidence judgments (RCJs) and FOK judgments. Metacognitive efficiency was estimated in 240 participants aged 19–79 years using a hierarchical Bayesian framework. Results showed that metacognitive efficiency for RCJs declined with age in the semantic task, even though task performance increased with age, while metacognitive efficiency was stable in the episodic task. Surprisingly, metacognitive efficiency was very low (although significantly higher than zero) for both FOK tasks regardless of age compared to similar previous studies. We suggested this might be due to the online testing. These results point to metacognition being multifaceted and varying according to judgment, domains, and populations.Des dissociations dans les types de tâches de mémorisation apparaissent lorsque l'on compare les jugements de sentiment de connaissance (FOK), les prédictions de performance à venir et la confiance rétrospective. Ce modèle a été utilisé pour élaborer des théories sur l'accès métacognitif à la mémoire, en particulier chez les groupes avec des troubles de la mémoire. En particulier, la sensibilité métacognitive des personnes âgées semble varier entre la mémoire épisodique (altérée) et la mémoire sémantique (intacte). Cependant, cela pourrait s'expliquer par les limites des mesures métacognitives et/ou les différences de mémoire. Nous avons voulu tester ces dissociations de la métacognition avec le vieillissement en comparant l'efficacité métacognitive dans des tâches épisodiques et sémantiques en utilisant deux types de jugement : les jugements de confiance rétrospectifs (RCJs) et les jugements FOK. L'efficacité métacognitive a été estimée chez 240 participants âgés de 19 à 79 ans àen s'appuyant sur un cadre hiérarchique bayésien. Les résultats ont montré que l'efficacité métacognitive pour les RCJs diminuait avec l'âge dans la tâche sémantique, même si la performance de la tâche augmentait avec l'âge, alors que l'efficacité métacognitive était stable dans la tâche épisodique. De manière surprenante, l'efficacité métacognitive était très faible (bien que significativement supérieure à zéro) pour les deux tâches FOK, quel que soit l'âge, par rapport à des études antérieures similaires. Nous avons suggéré que cela pouvait être dû au test en ligne. Ces résultats montrent que la métacognition est à facettes multiples et varie en fonction du jugement, des domaines et des populations
Looking for the origins of the human brain: the role of South Africa in the history of (palaeo)neurology
No full textInternational audienceIn 1925, Raymond Arthur Dart published his description and interpretations of the 'Taung Child' in the journal Nature, including a description of the natural brain endocast associated with the face and mandible. Details preserved in the endocast of the Taung Child have opened critical questions and debates about how the human brain evolved, and how to identify and study evidence of brain changes from fossil hominin crania. In this paper, we review and synthesise methodological innovations (how do we study fossil hominin brains?) and critical conceptual shifts (how did the hominin brain evolve?) triggered by the discovery of the Taung Child. In particular, we detail the impact of the study of the well-preserved crania and natural endocasts from the southern African hominin-bearing sites on our understanding of brain evolution and the integration of newly developed analytical tools into research in palaeoneurology (e.g. imaging techniques, 3D modelling). Additionally, we examine how the use of digital replicas of fossil hominin endocasts and the need to study extant human brains to form a comparative platform might raise questions about research practices (e.g. study and exhibition of fossil and extant human brains) and management of such invaluable heritage resources (e.g. data sharing). We finally consider how our view of human brain evolution, and in particular the putative uniqueness of the hominin brain, has changed over the last century
Three-dimensional dental topography of fossil suids and paleoenvironmental reconstruction of earliest Vallesian (Late Miocene) sites from the Vallès-Penedès Basin (NE Iberian Peninsula)
No full textInternational audienceThe earliest Vallesian (∼11.2 Ma) sites of Castell de Barberà (CB) and Creu de Conill 20 (CCN20), in the Vallès-Penedès Basin (NE Iberian Peninsula), are similarly well sampled but display differences in faunal composition that hint at paleoenvironmental differences. Most importantly, CB records one of the few co-occurrences of hominoids and pliopithecoids in the Miocene of Europe, while primates are seemingly absent from CCN20. Differences are also reflected in the more diverse suid assemblage from CB. To ascertain the paleoecological basis for such differences, here we investigate the diets of the suids from these sites—the suine Propotamochoerus palaeochoerus, the tetraconodontines Parachleustochoerus valentini and Versoporcus steinheimensis, and the listriodontine Listriodon splendens. We use 3D dental topography to infer paleodiet and provide further insight into the local paleoenvironmental differences between these sites. We measure four variables —orientation patch count, relief index, angularity, and mean surface slope— and distinguish herbivorous from omnivorous taxa, with the former categorized as browsers, mixed feeders, and grazers. The analyzed suids are similar in terms of angularity but differ in mean surface slope, orientation patch count and relief index. A canonical variate analysis classifies the CB and CCN20 suids as herbivorous (mixed feeders), except for P. palaeochoerus from CCN20, which displays greater similarities to omnivores (higher surface complexity), suggesting more varied diets in the latter locality. We conclude that, despite being roughly coeval and geographically close (∼10 km), these two sites record different local paleoenvironments —with CB representing a very humid and densely forested habitat, and CCN20 recording a more open, arid, and seasonal environment. This confirms previous inferences based on faunal composition and would explain the absense of primates from CCN20. Our study further highlights the relevance of local paleoenvironments for understanding differences in faunal composition among past communities from the same area
Prérequis et organisation du parcours de soins en vue de l’utilisation d’une thérapie cellulaire ou génique par cellules stromales mésenchymateuses (CSM) ou par cellules T porteuses d’un récepteur antigénique chimérique (CAR-T cells) chez les patients avec maladies auto-immunes systémiques
No full textInternational audienceFirst-line treatments of autoimmune systemic diseases (ARD) are based on the use of various types of immunosuppressive or immunomodulatory drugs, either alone or in association, according to standardized reference protocols. Prolonged use of these drugs in severe or refractory ARD is associated with high morbidity and increased mortality. Innovative cell therapies represent a new promising approach for patients with ARDs, with the recent clinical use of: a) mesenchymal stromal cells (MSCs), based on their immunomodulatory, antifibrotic and pro-angiogenic properties and b) Chimeric Antigen Receptors (CAR) T cell therapies T lymphocytes, where genetically modified expression of a chimeric antigen receptor (CAR-T cells). Therapeutic use of MSC or CAR-T cells, remains indications of exception in patients with severe ARDs resistant to prior standard therapies with new prerequisite and organisation of health-care pathways as compared to traditional drugs, not only for the Cell and Gene Therapy (CGT) product definition and delivery process, but also for the patient clinical management before and after administration of the CGT product. The aim of this workshop under the auspices of the French Speaking Society of Bone Marrow and Cell transplantation (SFGM-TC) working group on autoimmune diseases (MATHEC) is to describe: a) the prerequisite for French hospitals to set-up the specific health-care pathways for MSC or CART therapy in ARDs patients, in accordance with regulatory and safety needs to perform academic or industry sponsored clinical trials, and b) the care-pathway for ARD patients treated with CGT, highlighting the importance of working in tandem between the ARD and the CAR-T cell specialist all along the indication, procedures and follow-up of ARDs. Patient safety considerations are central to guidance on patient selection to be validated collectively at the multidisciplinary team meeting (MDTM) based on recent (less than 3 months) thorough patient evaluation. MSC and CAR-T procedural aspects and follow-up are then carried out within appropriately experienced and SFGM-TC accredited centres in close collaboration with the ADs specialist
InteropUnityCUDA: Un outil d'intéropérabilité entre Unity et CUDA
No full textInternational audienceUnity is a powerful and versatile tool for creating real time experiments. It comes with a homemade c-like language to program GPGPU massively parallel algorithms: Unity's compute shader language. As Unity has been primarily made for multi-platform games creation, this language comes with several limitations: for example, it does not support multi-GPU computation, and it lacks of complete math libraries.To overcome these flaws, the GPU manufacturers have developed programming models that allow developers to leverage the power of modern GPUs for general-purpose computing, like CUDA or HIP. Therefore, to bring these features and flexibility to Unity, this article proposes an open source tool to perform interoperability between Unity and CUDA.Unity est un outil puissant et polyvalent pour créer des expériences en temps réel. Il est livré avec un langage maison de type c pour programmer des algorithmes massivement parallèles GPGPU : Le langage compute shader d'Unity. Comme Unity a été principalement conçu pour la création de jeux multiplateformes, ce langage présente plusieurs limitations : par exemple, il ne prend pas en charge les calculs multi-GPU et ne dispose pas de bibliothèques mathématiques complètes.Pour pallier ces lacunes, les fabricants de GPU ont développé des modèles de programmation qui permettent aux développeurs d'exploiter la puissance des GPU modernes à des fins de calcul général, comme CUDA ou HIP. Par conséquent, pour apporter ces fonctionnalités et cette flexibilité à Unity, cet article propose un outil open source pour réaliser l'interopérabilité entre Unity et CUDA
Cathinone metabolism and biliary excretion in an ex-vivo pig liver model: example of 4-Cl-PVP and eutylone
No full textInternational audienceObjective: Recently, the pig liver model perfused ex vivo using a normothermic machine perfusion (NMP) has been proposed as a suitable model to study xenobiotic metabolism and biliary excretion. The aim of our study is to describe the metabolism of NPS such as cathinones (with a focus on 4-Cl-PVP and eutylone) in blood and bile, using a normothermic perfused pig liver model.Methods: Livers (n = 4) from male large white pigs, 3-4 months of age and weighing approximately 75-80 kg, were harvested and reperfused onto an NMP (LiverAssist®, XVIVO) using autologous whole blood at 38 °C. 4-Cl-PVP and eutylone were administered as a bolus in the circulating blood at T0 with the aim of achieving a concentration of 1 μg/mL in the reperfusion system. The assays were carried out on plasma and bile between 0 and 120 min after cathinone administration using an targeted and untargeted approaches based on liquid chromatography coupled with high resolution mass spectrometry (Q-Exactive Thermo Scientific®).Results: In plasma, the concentration of 4-Cl-PVP and eutylone decreased rapidly with elimination half-lives of 4 min and 0.25 min, respectively. Their phase I and phase II metabolites were detected in plasma as early as 1 min. In bile, 4-Cl-PVP and eutylone were detected with maximum intensity between 0 and 30 min post-administration, and the main metabolites found in plasma were found in bile. Phase II derivatives showed increasing biliary excretion over time up to 120 min.Conclusion: The pig liver model perfused ex vivo using an NMP represent a promising model in pharmaco-toxicology, particularly for toxicokinetic investigations of cathinones. This model may be of interest in the absence of authentic cases of cathinone consumption or other NPS consumption to identify relevant metabolites consumption markers. In addition, the possibility of collecting bile in this model represents an additional advantage for studying biliary excretion of NPS and their metabolites in forensic toxicology
Participation à une table ronde : l'égalité des genres dans l’éducation
No full textInternational audienceTable ronde organisée dans le cadre de la venue des partenaires européens de l’Espace Mendès France du projet Erasmus+ WISE [Welfare for Improved Social dimension of Education], à l’occasion d’une résidence de travail sur les questions d’égalité de genres dans les sciences, techniques et entrepreneuriat.Table ronde animée par Héloïse Morel, responsable du Lieu multiple, avec Joachim Benet, sociologue, université de Poitiers ; Isabelle Pianet, ingénieure de recherche au CNRS, membre de l’association Femmes et ; Céline Naudin, professeure de mathématiques au collège Jules Verne, coordinatrice de la classe à horaires aménagées Maths et Numérique et Cyril Naudin, proviseur adjoint du LP2I, ancien chargé de mission égalité filles-garçon au rectorat d’Académie de Poitiers
Characterization of cell and nucleus stiffness by coupling Scanning Ion Conductance Microscopy (SICM) and finite element modeling
No full textPart of the 49th congress of the Société de Biomécanique proceedingsInternational audienc
