1,721,203 research outputs found
Nouvelles propositions pour une physiologie de l 'action
No full textBerthoz Alain, Petit Jean-Luc. Nouvelles propositions pour une physiologie de l 'action. In: Intellectica. Revue de l'Association pour la Recherche Cognitive, n°36-37, 2003/1-2. Repenser le corps l'action et la cognition avec les neurosciences, sous la direction de Jean-Luc Petit. pp. 367-372
Switching from reaching to navigation: differential cognitive strategies for spatial memory in children and adults
No full textSwitching from reaching to navigation: differential cognitive strategies for spatial memory in children and adult
Anticipatory control and spatial cognition in locomotion and navigation through typical development and in cerebral palsy
No full textBehavioural evidence, summarized in this narrative review, supports a developmental model of locomotor control based on increasing neural integration of spatial reference frames. Two consistent adult locomotor behaviours are head stabilization and head anticipation: the head is stabilized to gravity and leads walking direction. This cephalocaudal orienting organization aligns gaze and vestibula with a reference frame centred on the upcoming walking direction, allowing anticipatory control on body kinematics, but is not fully developed until adolescence. Walking trajectories and those of hand movements share many aspects, including power laws coupling velocity to curvature, and minimized spatial variability. In fact, the adult brain can code trajectory geometry in an allocentric reference frame, irrespective of the end effector, regulating body kinematics thereafter. Locomotor trajectory formation, like head anticipation, matures in early adolescence, indicating common neurocomputational substrates. These late-developing control mechanisms can be distinguished from biomechanical problems in children with cerebral palsy (CP). Children's performance on a novel navigation test, the Magic Carpet, indicates that typical navigation development consists of the increasing integration of egocentric and allocentric reference frames. In CP, right-brain impairment seems to reduce navigation performance due to a maladaptive left-brain sequential egocentric strategy. Spatial integration should be considered more in rehabilitation. What this paper adds: Head stabilization to gravity and head anticipation of walking direction are fully developed around 11-13 years of age In adolescence, locomotor trajectories become smooth and consistent as a result of their planning in allocentric space. The Magic Carpet is a novel navigation task, showing that school-age children do not yet integrate egocentric and allocentric reference frames The motor and the cognitive aspects of locomotion can be differently affected and dissociated in children with cerebral palsy Early right-brain lesions reduce Magic Carpet performance inducing inefficient egocentric solving strategies Developmental Medicine and Child Neurology
Cognitive strategies for locomotor navigation in normal development and cerebral palsy
No full textCognitive strategies for locomotor navigation in normal development and cerebral pals
Sense of movement: Simplifying principles for humanoid robots
No full textBrain simplifying principles can improve robot capabilities, but currently robot control takes different paths.</jats:p
Bibliographie
No full textAndrieu Bernard et Berthoz Alain (dir.) (2011), Le Corps en acte. Centenaire Maurice Merleau-Ponty, Nancy, Presses universitaires de Nancy, coll. « Épistémologie du corps », 2011. Authié Colas N., Berthoz Alain, Sahel José-Alain et Safran Avinoam B. (2017), « Adaptive gaze strategies for locomotion with constricted visual field », Frontiers in Human Neuroscience, vol. 11, 2017 (DOI : 10.3389/fnhum.2017.00387). Baker Robert G. et Berthoz Alain (dir.) (1977), Control of Gaze by Brain Stem Neuro..
La disparition d’Alexandre Minkowski
No full textLazar Philippe, Kordon Claude, Huraux-Rendu Christiane, Berthoz Alain, Amiel-Tison Claudine, Moriette Guy, Papiernik Émile. La disparition d’Alexandre Minkowski. In: Santé, Société et Solidarité, n°1, 2004. Naître en France et au Québec. p. 10
Navigation strategies as revealed by error patterns on the Magic Carpet test in children with cerebral palsy
Get PDFShort-term memory develops differently in navigation vs. manual space. The Magic Carpet (MC) is a novel navigation test derived from the Walking Corsi Test and the manual Corsi Block-tapping Task (CBT). The MC requires mental rotations and executive function. In Cerebral Palsy (CP), CBT, and MC scores relate differently to clinical and lesional factors. Hypotheses of this study are: that frontal lesion specifically affect navigation in CP; that brain lesions affect MC cognitive strategies
Head stabilization in a humanoid robot: models and implementations
No full textNeuroscientific studies show that humans tend to stabilize their head orientation, while accomplishing a locomotor task. This is beneficial to image stabilization and in general to keep a reference frame for the body. In robotics, too, head stabilization during robot walking provides advantages in robot vision and gaze-guided locomotion. In order to obtain the head movement behaviors found in human walk, it is necessary and sufficient to be able to control the orientation (roll, pitch and yaw) of the head in space. Based on these principles, three controllers have been designed. We developed two classic robotic controllers, an inverse kinematics based controller, an inverse kinematics differential controller and a bio-inspired adaptive controller based on feedback error learning. The controllers use the inertial feedback from a IMU sensor and control neck joints in order to align the head orientation with the global orientation reference. We present the results for the head stabilization controllers, on two sets of experiments, validating the robustness of the proposed control methods. In particular, we focus our analysis on the effectiveness of the bio-inspired adaptive controller against the classic robotic controllers. The first set of experiments, tested on a simulated robot, focused on the controllers response to a set of disturbance frequencies and a step function. The other set of experiments were carried out on the SABIAN robot, where these controllers were implemented in conjunction with a model of the vestibulo-ocular reflex (VOR) and opto-kinetic reflex (OKR). Such a setup permits to compare the performances of the considered head stabilization controllers in conditions which mimic the human stabilization mechanisms composed of the joint effect of VOR, OKR and stabilization of the head. The results show that the bio-inspired adaptive controller is more beneficial for the stabilization of the head in tasks involving a sinusoidal torso disturbance, and it shows comparable performances to the inverse kinematics controller in case of the step response and the locomotion experiments conducted on the real robot
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