ISM | Page 5 | Institut des Sciences du Mouvement

5 Mar 2020

15:30 à 17:00

Mechanistic determinants of effector-independent motor memory encoding

Pratik MUTHA (Indian Institute of Techology). Invité par Fabrice SARLEGNA.

Coordinated, purposeful movements learned with one effector generalize to another effector, a finding that has important implications for tool use, sports, performing arts and rehabilitation. This occurs because the motor memory acquired through learning comprises components that are effector-independent. Despite knowing this for decades, the neural mechanisms and substrates that are causally associated with the encoding of effector-independent motor memories, remain poorly understood. Here we exploit inter-effector generalization, the behavioral signature of effector-independent memory representations, to address this crucial gap. We first show in healthy human participants that post-learning generalization across effectors is principally predicted by the level of an implicit mechanism that evolves gradually during learning and produces a temporally stable memory. We then demonstrate that interfering with left but not right posterior parietal cortex (PPC) using high-definition cathodal transcranial direct current stimulation impedes learning mediated by this mechanism, thus potentially preventing the encoding of effector-independent memories. We confirm this in our final experiment in which we show that disrupting left PPC but not primary motor cortex after learning has been allowed to occur, blocks inter-effector generalization. Collectively, our results reveal the key mechanism that encodes an effector-independent memory trace and uncover a central role for the PPC in its representation. Remarkably, the encoding of such motor memory components outside primary sensorimotor regions likely underlies a parsimonious neural organization that enables more efficient movement planning in the brain, independent of the effector used to act.

12 Mar 2020

14:00 à 16:15

Vers des applications de l'imagerie polarimétrique pour la robotique mobile

Olivier MOREL (Laboratoire Electronique, Informatique et Image; Université de Bourgogne & CNRS). Invité par Julien SERRES.

La présentation traitera de mes principales activités de recherche autour de l'imagerie polarimétrique et de ses applications. L’imagerie polarimétrique est une technique permettant de représenter les informations de polarisation issues d’un objet ou d’une scène sous forme matricielle. Initialement dédiée à des applications d’analyse purement optique, elle s’est rapidement développée ces dix dernières années avec la mise sur le marché de caméras polarimétriques. Ces dernières permettent d’envisager des applications en robotique mobile car leur taille est devenue compacte et les informations de polarisation peuvent être exploitées en temps réel. Après avoir introduit quelques notions élémentaires, je présenterai les premières applications que nous avons développées en imagerie médicale sur l'analyse de mélanomes et sur la numérisation d'organes par laparoscopie. Puis je décrirai des applications orientées vers la vision avec le calibrage et l'utilisation de capteurs polarimétriques et omnidirectionnelles. Je terminerai mon exposé avec des applications dédiées à la robotique mobile avec l'analyse de scènes et l'estimation d'attitude par vision polarimétrique.

Bio :

Diplômé de l'école d'ingénieurs Polytech Savoie en 2001, Olivier Morel a obtenu un DEA en Informatique et Instrumentation de l'Image à l'Université de Bourgogne en 2002.

Il a soutenu sa thèse de doctorat en 2005 sur des travaux portant sur la reconstruction d'objets métalliques par imagerie polarimétrique. Il est depuis 2007, Maître de Conférences à l'Université de Bourgogne et ses travaux de recherche concernent principalement l'utilisation de l'imagerie non-conventionnelle : omnidirectionnelle, polarimétrique pour des applications en robotique mobile. De 2016 à 2018 il a coordonné le projet ANR VIPeR (VIsion Polarimétrique pour la navigation de Robots) qui a permis de développer cette thématique de recherche au sein de l'équipe ERL Vibot CNRS 6000.

19 Mar 2020

14:00 à 16:00

REPORT DU AU COVID-19. In the black box: decoding and neuromodulation of cognitive control

Stefania FICARELLA (Centre de Recherche en Psychologie de la Connaissance, du Langage et de l’Émotion (PsyCLÉ), Aix-Marseille Université). Invitée par Fabrice SARLEGNA.

Cognitive control allows to attain one’s goals by flexibly adapting behaviour to the requirements of the internal and external environment. My research has focused on (i) how cognitive control is modulated by factors which are internal (e.g. intentions, decisions) and external (e.g. time pressure, outcome uncertainty) to the subject, (ii) how it determines outcomes’ evaluation and motor learning which, in turns, may modify the way we interact with the environment and, ultimately, one’s intention and state of mind. I will briefly introduce the non-invasive brain stimulation studies I’ve conducted to explore the inter-relation between the internal and external environment and the cognitive control of action. I will then present one EEG/EMG study that explores the evaluation of decisions’ outcome, specifically the conscious detection of partial errors, subthreshold incorrect motor activations which do not result in full errors. Finally, I will introduce a clinical study (dystonic patients) in which we coupled non-invasive electrical brain stimulation to neuroimaging (MEG) to investigate the role of the cerebellum in motor preparation during motor learning.

Scientific Bio:
After having obtained a PhD in Cognitive and Brain Sciences in 2015 from the University of Trente (Italy), where I worked at the Center for Neuroscience
and Cognitive System (Fondazione Istituto Italiano di Tecnologia)/Center for the Mind/Brain Sciences under the supervision of Dr. Lorella Battelli, I moved to France. From 2015 to 2018 I worked as postdoctoral fellow with the group of Dr. Boris Burle at the Laboratoire de Neurosciences Cognitives (Aix-Marseille Université, CNRS, Marseille, France) and I subsequently moved to Paris (France) for a second postdoc at the Institut du Cerveau et de la Moelle épinière (ICM), joining the équipe MOV'IT (Normal and abnormal motor control: movement disorders and experimental therapeutic), headed by Profs. Stéphane Lehéricy and Marie Vidailhet. Starting January 2020, I obtained a temporary teaching position (ATER) at the faculty of Psychology in Aix-En-Provence (France), joining the Centre de Recherche en Psychologie de la Connaissance, du Langage et de l’Émotion (PsyCLÉ).

26 Mar 2020

15:00 à 17:00

REPORT DU AU COVID-19. Neural computations of olfactory navigation.

Dominique MARTINEZ (LORIA, Nancy). Invité par Stéphane VIOLLET.

I will present my work in computational neuroscience and neuro-robotics aiming at understanding the odour-guided behaviour of animals, especially insects. At the application level, the challenge is to create innovative olfactory sensors and robots that reproduce certain aspects of animal behaviour. A virtuous circle is created where biological models benefit from robotic experiments and inspire them in return. The most demonstrative result concerns a hybrid robot with insect antennae as biosensors for the detection and localization of chemical sources.

Short bio : Dominique Martinez is a research director at the CNRS (Centre National de le Recherche Scientifique) in France. He works in the Neurosys team at LORIA (LOrraine laboratory of Research in Informatics and its Applications) which is a computer science laboratory located in Nancy, France. His research is in computational neuroscience and neuro-robotics, focused in chemical sensing in both animals and machines.

30 Apr 2020

14:00 à 16:15

Bone remodelling brick by brick. Mechanics and Biology.

Rachele Allena (ENSAM, Paris). Invitée par Martine Pithioux.

Bone remodelling is a very complex multiscale and multiphysics phenomenon. The initiation of such a process is triggered by the osteocytes, mechanosensible bone cells able to transform a mechanical signal into a chemical one (i.e. mechanotransduction). Such signals are transmitted via the lacuno-canalicular network (LCN) to the osteoclasts, which are responsible to resorb the old and/or damaged bone. Once the osteoclasts have their job done, the osteoblasts migrate to the specifc site and colonize it. They eventually mineralize and differentiate into osteocytes and the cycle can start again. Pathologies such as osteoporosis or microdamage may modify the connectivity and the morphology of the LCN and therefore induce the osteocytes apoptosis and consequently bone remodelling. Furthermore, microdamage is strictly related to the cortical bone orthotropy since it mostly occurs at the interfaces osteons-osteons and osteons-lamellae.

It is evident that many aspects must be taken into account in order to consistently describe bone remodelling and they involve cellular behaviour and functions, microstructure and anisotropic properties evolution, microdamage, coupling between mechanics and biology, mechanical stimuli to mention some of them.

In this presentation I will show the different bricks I have developed so far as my longterm objective is to describe bone remodelling via an orthotropic damage model of the cortical bone.

Rachele Allena,

Assistant Professor, HDR

Co-Chair BioMAT, BioMedical Engineering Master

7 May 2020

14:00 à 15:30

Robotique autonome

Prof. Rochdi MERZOUKI (Polytech'Lille, Centre de Recherche en Informatique, Signal et Automatique de Lille). Invité par Franck Ruffier.

https://webtv.univ-lille.fr/video/8967/robotique-autonome-par-rochdi-mer...

14 May 2020

14:00 à 15:30

Ant navigation.

Antoine WYSTRACH (Centre de Recherches sur le Comportement Animal – CNRS/Université Paul Sabatier, Toulouse ). Invité par Franck RUFFIER.

The remarkable navigational abilities of social insects are proof that small brains can produce exquisitely efficient, robust navigation in complex environments. Because social insects produce specialist foragers that are amenable to field and lab studies, they have been productive model systems for studies of navigation. Ideas derived from these studies of insect navigation have shown how simple mechanisms can produce robust and seemingly complex behaviour. I show here how simple low-resolution panoramic views, without the need for cognitive processes such as object identification or labelling provides an elegant solution to cope with the complexity of the world. Recent insect navigation research has only been possible because of techniques enabling the recording of visual scenes from the perspective of the insect. Without such techniques one has to intuit an animal’s point of view (its Umwelt) and I discuss how this may lead to unhelpful assumptions about the cues available for navigation. In the future, ants running on a track ball in front of screens displaying ecological environments may provide a powerful tool to understand how complex behaviours can emerge from the interaction between brain, body and environment.

Post-scriptum :

Antoine Wystrach obtained his licence in biology in Caen, with a special focus on neuroscience and ecology. He then went to Paris 13 University for a master in Ethology, where animal behaviour is studied at the crossroad between ecology, neuroscience and psychology. AW started his own research project on ant visual navigation and realised a PhD combining lab (in the university of Toulouse Paul Sabatier) and field experiments in Australia (with Macquarie university). He then obtained 2 years founding from the the Fyssen Foundation to pursue his research on ant navigation in Sussex University, with a stronger focus on modelling. AW then went at the University of Edinburgh involved in a European project with the aim of modelling the neural mechanisms underpinning learning in drosophila larvae. He pursues in the mean time his research on ant navigation by collaborating with his previous lab in Sussex and Macquarie Universities. Beyond the field of insect navigation, AW’s research shows how apparently complex behaviours can arise from surprisingly simple explanations, and thus has an impact in the field of comparative cognition.