GOFFART Laurent

Name : GOFFART
Surname : Laurent
Phone : 04 91 32 40 38
Fonction : Chercheur
Grade : CR1
Office : 2.05

Biography

Scientific investigations :

Equilibria and transitions : neurophysiology of the visuomotor presence

During the course of evolution, most animals were faced with the necessity to cope with the fact that their environment is not composed of stationary objects. In their world (Umwelt), the most significant events happen when things (animal or not, predator, prey, congener or else) move or when they move themselves. This reactive sensitivity to motion does not remain a passive contemplation; it is the opportunity for creating a link, spatiotemporally local, seeding the relation subject-object.

Our research is aimed at defining the neurophysiological substrate of this sensorimotor locosynchronization using the gaze orientation as an experimental probe.

The appearance of an event in the peripheral visual field indeed triggers 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 is now "visually captured" (it involves a larger number of neurons). It 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 (Hafed et al. 2009). The accuracy and precision of saccades and the symmetry of the unstable equilibrium that characterizes the so-called fixation (Goffart et al. 2012) do not remain randomly generated; they are guided by activities from the oculomotor cerebellum (Guerrasio et al. 2010; Quinet & Goffart 2015).

The foveal capture (foveation) also applies to targets that are moving. In this case, for the capture to be precise, the brain activity must develop signals that correspond to what would be called the "current spatiotemporal coordinates" of the targeted object (Fleuriet et al. 2011). Our works suggest that this neural dynamics defines in the best case, its here-and-now (hic-et-nunc) position (Fleuriet & Goffart 2012; Goffart, 2014; Bourrelly et al. 2014, 2015, 2016a,b). How is this 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)?

Some use the notions of prediction or internal model of the trajectory. But what is their neurophysiological explanation? Our experimental results lead us to consider instead attempts to synchronize with the present and current situation (Bourrelly et al. 2016). The repetition of this visuomotor presence yields a dynamic mnemonic "trace" which, in the physical world corresponds to the trajectory, but in the brain activity appears much more complex (Goffart et al. 2017). Moreover, prediction is more an operation consisting of actualizing a memorized experience (operation on the past) than a premonition, a bet about the future.

Using transient and local perturbation techniques (pharmacological inactivation, microstimulation), this research aims at defining the neuro-functional organization underlying the generation of an action that is spatiotemporally adapted to the on-going external conditions, on the basis of an afferent neuronal dynamics (Quinet & Goffart 2015) and a mnemonic dynamics built upon the past experience but actualized in the on-going action (Bourrelly et al. 2013, 2014, 2015, 2016). 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 of avoiding all teleological arguments, even refuting them.

This research is primarily performed in the non-human primate (macaque) in order to identify therefore the underlying neurophysiology. Efforts are being 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).

A selection of publications :

Synthesis works

Goffart L & Quinet J. Neurophysiologie de l’orientation saccadique du regard vers une cible visuelle. In: Autour de l’éthologie et de la cognition animale. F Delfour & MJ Dubois (Eds), ARCI, Presses Universitaires de Lyon, pp 19-33, 2005. hyperlien

Goffart L. Saccadic eye movements. In: Squire LR (ed.) Encyclopedia of Neuroscience, volume 8, pp. 437-444. Oxford: Academic Press, 2009. hyperlien

Goffart L. Singularités et coopérativités dans la réaction d’orientation. Ecole interdisciplinaire Berder 2011.

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

Goffart L. De la représentation cérébrale spatio-temporellement distribuée à la capture ici-et-maintenant d’un objet visuel en mouvement. in press 2017

Goffart L. De la représentation cérébrale spatio-temporellement distribuée à la capture ici-et-maintenant d’un objet visuel en mouvement. in presse 2017

Visual fixation as unstable equilibrium

Goffart L, Hafed ZM & Krauzlis RJ. Visual fixation as equilibrium: evidence from rostral superior colliculus inactivation. Journal of Neuroscience 32: 10627–10636, 2012. hyperlien

Goffart L, Quinet J, Chavane F & Masson GS Influence of background illumination on fixation and visually guided saccades in the rhesus monkey. Vision Research 46: 149 –162, 2006. hyperlien

Guerrasio L, Quinet J, Büttner U & Goffart L. The fastigial oculomotor region and the control of foveation during fixation. Journal of Neurophysiology 103: 1988-2001, 2010. hyperlien

Hafed ZM, Goffart L, Krauzlis RJ. Superior colliculus inactivation causes stable offsets in eye position during tracking. Journal of Neuroscience 28: 8124-8137, 2008. hyperlien

Hafed ZM, Goffart L & Krauzlis RJ. A neural mechanism for microsaccade generation in the primate superior colliculus. Science 323: 940-943, 2009. hyperlien

Taouali W, Goffart L, Alexandre F & Rougier N. A parsimonious computational model of visual target position encoding in the superior colliculus. Biological Cybernetics, 109: 549-559, 2015 hyperlien

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

Neural basis of spatiotemporal accuracy (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 in press 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

Fleuriet J & Goffart L. Saccadic interception of a moving visual target after a spatiotemporal perturbation. Journal of Neuroscience 32: 452–461, 2012. hyperlien

Fleuriet J, Hugues S, Perrinet L & Goffart L. Saccadic foveation of a moving visual target in the rhesus monkey. Journal of Neurophysiology 105: 883–895, 2011. hyperlien

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

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

Goffart L, Quinet J & Bourrelly C. Foveating a moving target, here-and-now. Journal of Vision 2014 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, 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 1004: 220-228, 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 92: 3351-3367, 2004. hyperlien

Hafed ZM, Goffart L, Krauzlis RJ. Superior colliculus inactivation causes stable offsets in eye position during tracking. Journal of Neuroscience 28: 8124-8137, 2008. hyperlien

Quinet J & Goffart L. Head unrestrained gaze shifts after muscimol injection in the caudal fastigial nucleus of the monkey. Journal of Neurophysiology 98: 3269–3283, 2007. hyperlien

Quinet J & Goffart L. Electrical microstimulation of the fastigial oculomotor region in the head unrestrained monkey. Journal of Neurophysiology 102: 320-336, 2009. hyperlien

Quinet J & Goffart L. Cerebellar control of saccade dynamics: contribution of the fastigial oculomotor region. Journal of Neurophysiology 113: 3323-3336, 2015. hyperlien

Quinet J & Goffart L. Does the brain extrapolate the position of a transient moving target? Journal of Neuroscience 35: 11780-11790, 2015. hyperlien

Internet links:

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

Goffart L. Brain processes for foveating a visual target here-and-now. Seminar Los Angeles UCLA 2016: https://hal.inria.fr/hal-01402663

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

https://cnrs.academia.edu/LaurentGoffart

Biography :

  • 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)
  • 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 led me to focus on the saccadic orienting reaction and to the morphogenesis. Pellionisz-Llinas (1982) was seminal in my search for the neurobiological foundations of S & T. The reflections of Henri Poincaré lead to the idea that these notions might merely be social conveniences conventions (concepts): S-T are 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).

Current perspectives: learning, memory, real-time immersion, dynamic morphing, neuro-epistemology, sensorimotor presence, contact, link ...

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