Référentiels pour l'intégration multisensorielle et sensorimotrice : une approche neuro-robotique

Le sujet de cette thèse aborde le problème de la représentation de l'espace dans la boucle sensorimotrice chez le primate et sur des systèmes robotiques. Chez l'être vivant, l'intégration multisensorielle passe par la problématique des référentiels pour lesquels il existe des modèles théoriques basés sur des données électrophysiologiques. Cependant ces derniers n'expliquent pas tous les résultats issus des travaux en neurosciences. Dans une première partie de l'étude, nous avons enregistré et mis en évidence, chez le singe vigile, l'influence de la direction de la tête par rapport au corps et de son interaction avec celle de l'œil par rapport à la tête au sein de l'aire visuelle primaire (V1) sous forme de modulation de l'activité neuronale. L'effet de la position de la tête n'avait été, jusqu'à présent, montré que dans le cortex pariétal, aire hautement intégrative. Nos résultats mettent clairement en évidence l'existence d'une intégration distribuée et d'une construction d'une représentation stable et unifiée en amont du cortex pariétal. Ces intégrations semblent exister également après le cortex pariétal postérieur. Des résultats électrophysiologiques, longtemps ignorés mais confirmés récemment ont montré l'influence de la position des yeux au sein du cortex prémoteur dorsal. Une deuxième étude basée sur le formalisme de l'asservissement visuel en robotique, nous a permis de proposer une interprétation de ces résultats. La mise en œuvre d'un réseau de neurones artificiels entraîné à partir de ce formalisme montre la similitude de l'influence des effets de la position des yeux observés au niveau cortical et confirme notre interprétation. Sur l'ensemble de tous ces travaux, nous proposons une discussion sous l'angle des deux formalismes neuro-robotique où nous présentons un bilan fonctionnel de la perception à l'action. Finalement, nous proposons l'existence d'une origine multisensorielle qui avantagerait l'intégration multisensorielle en neurosciences comme en robotique.This thesis is an interdisciplinary approach in Neuroscience and robotics that investigates the frame of references based on multisensory integration in the sensorimotor loop. Theoretical modeling based on experimental studies in neuroscience have been proposed but are not satisfactory. In a first study we have performed electrophysiological recordings in the primary visual cortex of a behaving monkey and showed that extraretinal signals related to the eye position and to the neck position modulate visual activity of cortical neurons. This result parallels previous data shown in the parietal cortex and strongly suggest a distributed cortical mechanism for construction of space representation. The second study aimed to interpret the modulation, due to eye position relative to the head, of the neuronal activity in the dorsal premotor cortex. For this, humanoid robotics formalisms were used, in particular visual servoing. We used this purely mathematical model to train an artificial neural network in order to show similarities between artificial neural activity and biological neuronal activity. From this work, we propose a discussion in terms of both neuroscience and robotics formalisms, where we present a functional assessment from perception to action. Finally, we propose the existence of a multisensory origin that would benefit the multisensory integration in neuroscience as in robotics

A robotics approach for interpreting the gaze-related modulation of the activity of premotor neurons during reaching

International audienceThis paper deals with the modeling of the activity of premotor neurons associated with the execution of a visually guided reaching movement in primates. We address this question from a robotics point of view, by considering a simplified kinematic model of the head, eye and arm joints. By using the formalism of visual servoing, we show that the hand controller depends on the direction of the head and the eye, as soon as the hand-target difference vector is expressed in eye-centered coordinates. Based on this result, we propose a new interpretation of previous electrophysiological recordings in monkey, showing the existence of a gaze-related modulation of the activity of premotor neurons during reaching. This approach sheds a new light on this phenomenon which, so far, is not clearly understood

Humanoid human-like reaching control based on movement primitives

This paper deals with the problem of generating realistic human-like reaching movements from a small set of movement primitives. Two kinds of movement databases are used as reference. The first one is obtained numerically, by applying biological principles of motor control on the dynamic model of the robot arm. The second one is obtained by recording reaching movements of human subjects. From these databases, primitives are extracted and analyzed by using Principal Component Analysis. An original generalization method is then proposed for generating movements that did not belong to the initial database. We show that twenty primitives allow to produce new movements, having characteristics similar to that of humans. Experiments on the humanoid robot HRP-2 are presented to illustrate the result

Référentiels pour l'intégration multisensorielle et sensorimotrice (une approche neuro-robotique)

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Why should we use 3D Collaborative Virtual Environments for Cyber Security?

International audienc

3D CyberCOP: a Collaborative Platform for Cybersecurity Data Analysis and Training

in proceedings of CDVE 2018 (15th International Conference on Cooperative Design, Visualization and Engineering), Springer, p. 176-183, Hangzhou, China, October 21-24, 2018International audienceAlthough Immersive Analytics solutions are now developed in order to ease data analysis, cyber security systems are still using classical graphical representations and are not harnessing yet the potential of virtual reality systems and collaborative virtual environments. 3D Col-laborative Virtual Environments (3DCVE) can be used in order to merge learning and data analysis approaches, as they can allow users to have a better understanding of a cyber situation by mediating interactions towards them and also by providing different points of view of the same data, on different scales. So we propose a 3D Cyber Common Operational Picture (3D CyberCOP) that will allow operators to face together a situation by using immersive and non immersive visualizations and by collaborating through user-defined roles. After visiting French Security Operations Centers (SOCs), we have defined a collaborative interaction model and some use-cases, to assess of the effectiveness of our solution

From Cyber Security Activities to Collaborative Virtual Environments Practices through the 3D CyberCOP Platform

International audienceAlthough collaborative practices between cyber organizations are well documented, managing activities within these organizations is still challenging as cyber operators tasks are very demanding and usually done individually. As human factors studies in cyber environments are still difficult to perform, tools and collaborative practices are evolving slowly and training is always required to increase teamwork efficiency. Contrary to other research fields, cyber security is not harnessing yet the capabilities of Collaborative Virtual Environments (CVE) which can be used both for immersive and interactive data visualization and serious gaming for training. In order to tackle cyber security teamwork issues, we propose a 3D CVE called the 3D Cyber Common Operational Picture, which aims at taking advantage of CVE practices to enhance cyber collaborative activities. Based on four Security Operations Centers (SOCs) visits we have made in different organizations, we have designed a cyber collaborative activity model which has been used as a reference to design our 3D CyberCOP platform features, such as asymetrical collaboration, mutual awareness and roles specialization. Our approach can be adapted to several use cases, and we are currently developing a cyber incident analysis scenario based on an event-driven architecture, as a proof of concept

Deamidation and disulfide bridge formation in human calbindin D28k with effects on calcium binding

Calbindin D28k (calbindin) is a cytoplasmic protein expressed in the central nervous system, which is implied in Ca2+ homeostasis and enzyme regulation. A combination of biochemical methods and mass spectrometry has been used to identify post-translational modifications of human calbindin. The protein was studied at 37°C or 50°C in the presence or absence of Ca2+. One deamidation site was identified at position 203 (Asn) under all conditions. Kinetic experiments show that deamidation of Asn 203 occurs at a rate of 0.023 h−1 at 50°C for Ca2+-free calbindin. Deamidation is slower for the Ca2+-saturated protein. The deamidation process leads to two Asp iso-forms, regular Asp and iso-Asp. The form with regular Asp 203 binds four Ca2+ ions with high affinity and positive cooperativity, i.e., in a very similar manner to non-deamidated protein. The form with β-aspartic acid (or iso-Asp 203) has reduced affinity for two or three sites leading to sequential Ca2+ binding, i.e., the Ca2+-binding properties are significantly perturbed. The status of the cysteine residues was also assessed. Under nonreducing conditions, cysteines 94 and 100 were found both in reduced and oxidized form, in the latter case in an intramolecular disulfide bond. In contrast, cysteines 187, 219, and 257 were not involved in any disulfide bonds. Both the reduced and oxidized forms of the protein bind four Ca2+ ions with high affinity in a parallel manner and with positive cooperativity

Qui veut laver ma blouse ? La légitimation collective d’activités teintes. Le cas des équipes de gestion de pôles

National audienceFrench hospitals’ governance reform has, directly or not, created new roles: clinical directors, senior nurse assistants, business managers and executive managers. These roles are still recent and not yet legitimate within hospitals. Furthermore, they are associated with a strong social stigma in those organizations: care management. Our work aims at better understanding the way clinical directions’ teams consider their management activities as dirty work; and the strategies through which they try to legitimate these activities in front of their colleagues. We carried out a case study of 7 “Mother-Child” clinical directions’ teams in France, through a qualitative methodology (56 interviews, including 25 interviews with targeted actors; 20 observations of directorate meetings). Our results show that activity legitimization strategies vary depending on actors and teams. They are both organizationally based (delegation) and discursively based (reframing, recalibrating, audience diversifying). We specifically suggest that these strategies depend on clinical directions’ team organization. We discuss two layouts of strategies: strategies of clinical director’s delegation and those of collective commitment. Tinted roles’ legitimization thus depends on both individuals’ discursive resources (and places for discussions) and individual’s power within the organization (and hierarchical and functional relationships).Directement ou non, la nouvelle gouvernance hospitalière a créé de nouveaux rôles : chef de pôle d’activité, cadre coordonnateur de pôle, cadre administratif de pôle, directeur délégué de pôle. Ces rôles, encore récents et peu légitimes au sein des hôpitaux, sont en plus associés à une teinte sociale encore prégnante dans ces organisations : la gestion des soins. Notre travail vise à mieux comprendre la manière dont les équipes de pôle conçoivent leurs activités de gestion en tant que sale boulot ; ainsi que les stratégies par lesquelles ils tentent de les légitimer auprès de leurs collègues. Pour cela, nous avons mené une étude de 7 cas d’équipes de gestion de pôles « Mère-Enfant » en France, à partir d’une démarche qualitative (56 entretiens, dont 25 avec les acteurs ciblés ; 20 observations de réunions de pôle). Nos résultats montrent que les stratégies de légitimation des activités diffèrent selon les acteurs et les équipes de pôle. Elles sont à la fois d’ordre organisationnel (délégation) et discursif (recadrage, recalibrage, diversification de l’audience). En particulier, nous avançons que ces stratégies découlent des modes d’organisation dans chaque équipe de pôle. Notre discussion nous amène à distinguer deux configurations de stratégies : les stratégies par délégation du chef de pôle et celles par endossement de l’ensemble de l’équipe. La légitimation de rôles teintés dépend donc à la fois des ressources discursives des individus (et donc des instances de dialogue) mais aussi du pouvoir de chacun dans l’organisation (et donc des liens hiérarchiques et fonctionnels qui les unissent)

Certifié « Cadre administratif de pôle ». L’encastrement identitaire pour légitimer un nouveau rôle

International audienceThe hospital new governance reform has created a brand new role of administrative man- ager of clinical directorates. This administrative manager should assist a clinical director, along with a senior nurse, however he has no clear instruction about his/her activities, while his/her environment is highly institutionalized. This article aims at investigating the legitimization process of this new role within clinical directorates’ teams: how adminis- trative managers try to legitimize their role as perceived by their colleagues? To address the issue, we resort to the literature relating to both new organizational practices legit- imization, and identity work; our empirics consists in case studies of 4 “Mother-Child” clinical directorate teams in France, each of one involving an administrative manager. We proceed through qualitative methods including 30 interviews and 8 meeting observations. Our results show how administrative managers struggle to integrate their identity into their colleagues’ work systems, while justifying to them the usefulness of their role. We finally discuss the concept of identity embeddedness in relation to neo-institutional and identity work theories, as well as implications for clinical directory teams.La nouvelle gouvernance hospitalière a créé un nouveau rôle de cadre administratif de pôle d’activité, rôle totalement inédit dans les hôpitaux. Censé assister le chef de pôle, en collaboration avec un cadre coordonnateur, ce cadre administratif n’a cependant pas une ligne de fonctionnement claire, d’autant plus dans un environnement qui, lui, est fortement institutionnalisé. Nous posons dans ce travail la question de la légitimation de ce nouveau rôle au sein des équipes de pôle : comment les cadres administratifs procèdent-ils pour légitimer leur rôle aux yeux de leurs collègues ? Pour y répondre, nous mobilisons la litté- rature concernant la légitimation de nouvelles pratiques ainsi que celle relative au travail identitaire ; puis nous utilisons une étude de 4 cas d’équipes de pôle « Mère-Enfant » en France, comprenant chacune un cadre administratif, à partir d’une démarche qualitative (30 entretiens, 8 observations de réunions). Nos résultats montrent comment les cadres administratifs de pôle s’attèlent à insérer leur identité dans le fonctionnement des équipes de pôle, tout en justifiant l’utilité de leur rôle auprès de ces acteurs. Nous discutons finalement le concept d’encastrement identitaire en lien avec la théorie néo-institutionnelle et celle du travail identitaire, ainsi que les implications pour la gestion des équipes de pôle