GOFFART Laurent

Name : GOFFART
Surname : Laurent
Phone : 04 91 32 40 38
Fonction : Chercheur
Grade : CRCN
Office : 2.05

Biography

"A humble approach is the one that lets the brain be investigated in its own grandeur instead of reducing it into a flat shadow" (Andras Pellionisz)

EQUILIBRIA AND TRANSITIONS : NEUROPHYSIOLOGY OF ORIENTATION AND VISUOMOTOR PRESENCE

How do activities of interconnected microscopic elements (neurons) enable a macroscopic organism to reach a visual object located in its external physical world ? In other words, how do we relate neuronal activities with kinematic measurements ? How do we relate events which are measured in mediums of different scales, temporalities and complexity orders ?

During the course of Evolution, most animals were faced with the necessity to cope with a dynamic environment. In the world peculiar to each species (Umwelt), the most significant events happen when things (animal or not, predator, prey, congener or else) move or when they move themselves. Endowed with a sensitivity and a reactivity to motion, the animals managed to interact with the objects of the external world, their interactions consisting of establishing contacts and links around zones of less instabilities; The sensitivity does not resume to the passive contemplation of a streaming landscape ; it is a "combative" engagement, the opportunity for creating spatiotemporally local links, for creating accompaniments, i.e., a sensorimotor presence constituting a relation subject-"object" which is oriented (considering disorientation at the origin of panic reactions and escape).

Our research is aimed at characterizing the neurophysiology of this relationship, dynamic and spatial, that an animal establishes with the objects of its visual environment, using the gaze orientation of the monkey as a model for comprehending human neurological disorders and also as an experimental probe. Aware of the stratification of measured phenomenon, we defend the following theoretical viewpoint: the zones of interaction are multipolar equilibria and the movements (saccadic or slow) are their restoration with dynamics which are determined by the intrinsic properties of mobilized sensorimotor channels.

The appearance of an event in the peripheral visual field triggers a transition, a rapid orienting gaze shift (saccade) at the end of which the image of the object becomes more or less well projected onto the retinal area endowed of the greatest visual acuity (the fovea). Thus, brought within the central visual field, the target involves a larger number of neurons. The reached equilibrium is represented by a bilateral cerebral activity whose fluctuations in the superior colliculus are proposed to be the origin of those microsaccades observed during visual fixation. We have shown that the symmetry of this unstable equilibrium involves the oculomotor cerebellum through the two caudal fastigial nuclei. We have also characterized how the neurons of these nuclei intervene in the restoration (saccade) of the equilibrium broken by any asymmetrical visual stimulus.

The foveal capture (foveation) also applies to targets that are moving. In this case, for the capture to be accurate, the brain activity must develop signals that correspond to what would be called the "current spatiotemporal coordinates" of the targeted object. Our works suggest that this neural dynamics defines in the best case, its here-and-now (hic-et-nunc) position. How is this physically local and "sharp" representation possible when one considers the multiple delays of neuronal conduction and the distributed encoding of a visual object in the brain? What is the internal structure of this thing that the classical measurements reduce to a point (x,y,z,t)?

Notions of prediction or internal model of the trajectory are sometimes used. But what do these notions mean in neurophysiological language? Our experimental results lead us to consider instead attempts to synchronize with the present and current situation. The repetition of this visuomotor presence (engagements) yields a dynamic mnemonic "trace" which, in the physical world corresponds to the trajectory, but in the brain activity appears to be a recruitment of resources. We do neither use the notion of prediction because it postulates a notion (the future) which is a cultural concept, likely meaningless at the neuronal level. As a matter of fact, when we study the activity of collicular neurons during interceptive saccades, we discover a "horizon" that does not expand beyond the locus/time of capture. In order to aim at understanding how a memorized experience is being actualized within the action, we prefer to avoid notions of premonition or gamble, and study the construction of sensorimotor schemes which are exact, i.e., efficient for the survival of the macroscopic organism.

Using transient and local perturbation techniques (pharmacological inactivation, microstimulation), this research aims at defining the neuro-functional organization that enables us to generate actions which are spatiotemporally adapted to the on-going external conditions, on the basis of an afferent neuronal dynamics and a mnemonic dynamics built upon the past experience but actualized in the on-going action. We want to understand how this is made possible, neurophysiologically speaking, i.e., to identify the channels and flows of neuronal activity which are hidden behind these multiple shortcuts, often vague and sterile, like internal model, etc., taking care also of avoiding any teleological argument, even refuting them because we do not think that the nervous system is a "machine" akin to most of those invented by homo faber.

This research is primarily performed in the non-human primate (macaque monkey) in order to identify the underlying neurophysiology and promote the neurology of sensorimotor disorders. Efforts have also been developed to extend it to other animal varieties such as the insect (hyperlien), in collaboration with Drs Y. Yamawaki and T. Carle (Kyushu University, Japan), with the aim to define more fundamentally, with neurobiological terms, the visuomotor presence, i.e., the locus and the instant of sensorimotor interaction which, once again, must not be considered as a point but as a dynamical equilibrium.

A selection of publications :

Syntheses

Goffart L. Itinéraire pour une contribution de la Neurophysiologie de l’orientation du regard à la recherche des conditions de possibilité de l’intuition spatiale. report for the habilitation to direct research 2020 hyperlien

Goffart L. Kinematics and the neurophysiological study of visually-guided eye movements. Progress in Brain Research 2019 hyperlien

Goffart L, Bourrelly C & Quinton J-C. Neurophysiology of visually-guided eye movements: Critical review and alternative viewpoint. Journal of Neurophysiology 2018 hyperlien

Goffart L. De la représentation cérébrale spatio-temporellement distribuée à la capture ici-et-maintenant d’un objet visuel en mouvement. In: L’avenir de la complexité et du désordre, Lévy J-C S & Ofman S Editions matériologiques 2018. hyperlien

Goffart L, Bourrelly C & Quinet J. Synchronizing the tracking eye movements with the motion of a visual target: basic neural processes. Progress in Brain Research 2017. hyperlien

Goffart L. Saccadic eye movements: Basic neural processes. Reference Module in Neuroscience and Biobehavioral Psychology 2017. hyperlien

Neural basis of spatiotemporal congruence (here-and-now)

Bourrelly C, Quinet J & Goffart L. Equilibria and transitions during visual tracking: Learning to track a moving visual target in the monkey. Society for Neuroscience Abstracts 2013. hyperlien

Bourrelly C, Quinet J & Goffart L. Unsupervised dynamic morphing of a spatiotemporal visual event during its oculomotor tracking. Journal of Vision 2014. hyperlien

Bourrelly C, Quinet J & Goffart L. Evolution of the oculomotor tracking with an accelerating or decelerating target Journal of Vision 2015. hyperlien

Bourrelly C, Quinet J, Cavanagh P & Goffart L. Learning the trajectory of a moving visual target and evolution of its tracking in the monkey. Journal of Neurophysiology 2016a. hyperlien

Bourrelly C, Quinet J, Cavanagh P & Goffart L. Abstraction of 2D head-centered positions from tracking a moving visual target: A study in the non-human primate. Soc. Neurosci. Abstr. 2016b. hyperlien

Bourrelly C, Quinet J & Goffart L. The caudal fastigial nucleus and the steering of saccades toward a moving visual target. Journal of Neurophysiology 2018. hyperlien

Bourrelly C, Quinet J & Goffart L. Pursuit disorder and saccade dysmetria after caudal fastigial inactivation in the monkey. Journal of Neurophysiology 2018. hyperlien

Fleuriet J & Goffart L. Saccadic interception of a moving visual target after a spatiotemporal perturbation. Journal of Neuroscience 2012. hyperlien

Fleuriet J, Hugues S, Perrinet L & Goffart L. Saccadic foveation of a moving visual target in the rhesus monkey. Journal of Neurophysiology 2011. hyperlien

Goffart L. Parallel and continuous visuomotor processing of simultaneously moving targets.Journal of Vision 2017. abstract hyperlien poster hyperlien

Goffart L, Cecala A & Gandhi N. The superior colliculus and the steering of saccades toward a moving visual target. Journal of Neurophysiology 2017b. hyperlien

Goffart L, Chen LL & Sparks DL. Saccade dysmetria during functional perturbation of the caudal fastigial nucleus in the monkey. Annals of the New York Academy of Sciences 2003. hyperlien

Goffart L, Chen LL & Sparks DL. Deficits in saccades and fixation during muscimol inactivation of the caudal fastigial nucleus in the rhesus monkey. Journal of Neurophysiology 2004. hyperlien

Goffart L & Fleuriet J. Hic-et-nunc (here-and-now) encoding of a moving target for its saccadic foveation. i-Perception 2012. hyperlien

Goffart L & Fleuriet J. Dynamic morphing of a spatiotemporal event for the orienting reaction. In: Ladislav Tauc & GDR MSPC Neurosciences Conference 2010.

Goffart L, Quinet J & Bourrelly C. Foveating a moving target, here-and-now. Journal of Vision 2014. hyperlien

Hafed ZM, Goffart L, Krauzlis RJ. Superior colliculus inactivation causes stable offsets in eye position during tracking. Journal of Neuroscience 2008. hyperlien

Quinet J & Goffart L. Head unrestrained gaze shifts after muscimol injection in the caudal fastigial nucleus of the monkey. Journal of Neurophysiology 2007. hyperlien

Quinet J & Goffart L. Electrical microstimulation of the fastigial oculomotor region in the head unrestrained monkey. Journal of Neurophysiology 2009. hyperlien

Quinet J & Goffart L. Cerebellar control of saccade dynamics: contribution of the fastigial oculomotor region. Journal of Neurophysiology 2015. hyperlien

Quinet J & Goffart L. Does the brain extrapolate the position of a transient moving target? Journal of Neuroscience 2015. hyperlien

Quinton J-C & Goffart L. A unified neural field model of the dynamics of goal-directed eye movements. Connection Science 30: 20-52, 2018. hyperlien

Gaze direction as equilibrium

Goffart L, Hafed ZM & Krauzlis RJ. Visual fixation as equilibrium: evidence from rostral superior colliculus inactivation. Journal of Neuroscience 2012. hyperlien

Guerrasio L, Quinet J, Büttner U & Goffart L. The fastigial oculomotor region and the control of foveation during fixation. Journal of Neurophysiology 2010. hyperlien

Hafed ZM, Goffart L & Krauzlis RJ. Superior colliculus inactivation causes stable offsets in eye position during tracking. Journal of Neuroscience 2008. hyperlien

Hafed ZM, Goffart L & Krauzlis RJ. A neural mechanism for microsaccade generation in the primate superior colliculus. Science 2009. hyperlien

Hafed ZM & Goffart L. Gaze direction as equilibrium: more evidence from spatial and temporal aspects of small-saccade triggering in the rhesus macaque monkey. Journal of Neurophysiology 2020. hyperlien

Krauzlis R, Goffart L. & Hafed ZM. Neuronal control of fixation and fixational eye movements. Philosophical Transactions of the Royal Society B, 20160205, 2017.

Taouali W, Goffart L, Alexandre F & Rougier N. A parsimonious computational model of visual target position encoding in the superior colliculus. Biological Cybernetics 2015 hyperlien

Internet links:

http://www.cnrs.fr/insb/recherche/p...

Goffart L. Brain processes for foveating a visual target here-and-now. Séminaire Los Angeles UCLA 2016: hyperlien

Goffart L. Neural processes underlying the accurate foveation and tracking of a visual target. Séminaire pour Kolloquium der Abteilung Allgemeine Psychologie/ Current Topics in Perception and Cognition, Prof. Karl Gegenfurtner, Giessen, Allemagne, 2018. hyperlien

https://www.researchgate.net/profil...

https://cnrs.academia.edu/LaurentGoffart

BIOGRAPHY :

2019 june 27th: monograph (written in French) for obtaining the habilitation to direct researches "Itinerary for a contribution of the Neurophysiology of gaze orientation to the research of the conditions of possibility of spatial intuition", Aix-Marseille University

2016-2020: preparation of a Doctorate of Philosophy at Centre Gilles Gaston Granger under the mentorship of Prof. G. Crocco and Dr I. Ly http://centregranger.cnrs.fr/spip.p...

2016: master degree in History and Philosophy of Fundamental Sciences (Aix-Marseille Université); Research report: Contribution critique à la recherche des fondements neuro-psycho-physiologiques de la notion d’espace (Prof. G. Crocco, Dr I. Ly)

1996: Philosophiae Doctor in Neurosciences (Claude Bernard University Lyon I); Thesis: L’orientation saccadique du regard vers une cible: étude de la contribution du cervelet médio-postérieur chez le chat en condition "tête libre" no 70-96 (Committee: Prof. W. Becker, Prof. A. Berthoz, Prof. J.M. Coquery, Dr G. Gauthier, Prof. M. Jeannerod, Dr D. Pelisson, Prof. A. Roucoux)

  • publications resulting from the doctoral work:
    • Pelisson D, Goffart L & Guillaume A. Control of saccadic eye movements and combined eye/head gaze shifts by the medio-posterior cerebellum. In: Neural control of space coding and action production (Eds. C. Prablanc, D. Pélisson and Y. Rossetti), Progress in Brain Research vol. 142, Elsevier, Amsterdam, pp 69-89, 2003. hyperlien
    • Pelisson D, Goffart L, Guillaume A & Quinet J. Visuomotor deficits induced by fastigial nucleus inactivation. The cerebellum 2: 71-76, 2003. hyperlien
    • Guillaume A, Goffart L, Courjon JH & Pelisson D. Altered visuomotor behavior during inactivation of the caudal fastigial nucleus in the cat. Experimental Brain Research 132: 457-463, 2000. hyperlien
    • Guillaume A, Goffart L & Pelisson D. Learning from cerebellar lesions about the temporal and spatial aspects of saccadic control. Behavioral and Brain Sciences 22: 687-688, 1999.
    • Goffart L & Pelisson D. Orienting gaze shifts during muscimol inactivation of the caudal fastigial nucleus in the cat. I. Gaze dysmetria. Journal of Neurophysiology 79: 1942-1958, 1998. hyperlien
    • Goffart L, Pelisson D & Guillaume A. Orienting gaze shifts during muscimol inactivation of the caudal fastigial nucleus in the cat. II. Dynamics and eye-head coupling. Journal of Neurophysiology 79: 1959-1976, 1998. hyperlien
    • Pelisson D, Goffart L & Guillaume A. Contribution of the rostral fastigial nucleus to the control of orienting gaze shifts in the head-unrestrained cat. Journal of Neurophysiology 80: 1180-1196, 1998. hyperlien
    • Goffart L, Guillaume A & Pelisson D. Compensation for gaze perturbations during inactivation of the caudal fastigial nucleus in the head-unrestrained cat. Journal of Neurophysiology 80: 1552-1557, 1998. hyperlien
    • Goffart L & Pelisson D. Changes in initiation of orienting gaze shifts after muscimol inactivation of the caudal fastigial nucleus in the cat. Journal of Physiology (London) 503.3: 657-671, 1997. hyperlien
    • Goffart L & Pelisson D. Cerebellar contribution to the spatial encoding of orienting gaze shifts in the head-free cat. Journal of Neurophysiology 72: 2547-2550, 1994. hyperlien
    • Goffart L & Pelisson D. Implication of the fastigial nucleus in target localization and execution of orienting gaze shifts in the cat. In: "Contemporary ocular motor and vestibular research: A tribute to David A. Robinson" A.F. Fuchs, T. Brandt, U. Büttner et D. Zee (Eds) Thieme Verlag, Stuttgart, pp 282-284, 1994.
  • 1991: master degree in Physiology (Lille University of Science and Technology - Lille I)
  • 1990: master degree in Psychology (Charles de Gaulle University – Lille III); Research report: Posture oculaire et facilitation cutanée du réflexe de Hoffmann (Prof. J.M. Coquery, Dr J. Honoré)

My scientific engagement starts in 1983 with the discovery of the kantian conceptions of space (S), time (T) and knowledge acquisition. The piagetian constructivism, the catastroph theory and the Physiology (Schiller & Stryker 1972; Changeux 1983; Jeannerod 1988; Paillard 1986) led me to focus on the saccadic orienting reaction and to its morphogenesis. Pellionisz-Llinas (1982) triggered the orientation of my research toward the contribution of the cerebellum. The reflections of Henri Poincaré leading to the idea that these notions might merely be collective conventions (concepts), S-T is then being replaced by a "lattice" of neuronal activation trajectories "weaved" (or "paved") by processes triggered whenever an external object is captured (contact here-and-now).

  • Changeux J-P (1983) L’homme neuronal. Fayard.
  • Jeannerod M (1988) The neural and behavioural organization of goal-directed movements. Oxford University Press.
  • Paillard J (1986) Itinéraire pour une psychophysiologie de l’action. Editions Actio.
  • Pellionisz A & Llinas R (1982) Space-time representation in the brain. the cerebellum as a predictive space-time metric tensor. Neuroscience 7: 2949-2970.
  • Schiller PH & Stryker M (1972) Single-unit recording and stimulation in superior colliculus of the alert rhesus monkey. J Neurophysiol 35: 915-924.

CURRENT PERSPECTIVES : learning, memory, real-time immersion, dynamic morphing, neuro-epistemology, sensorimotor presence, contact, link, spatial synchronization ...

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