Soutenance de thèse de Nicolas Orlando-Dessaints, inVibe team
Wednesday 20th December 2023, at 10:00 AM, Faculté de Médecine, salle de thèse 2
Nicolas Orlando-Dessaints, inVibe team (Inférence et Comportements Visuels)
Etude comportementale et neurophysiologique de l’extrapolation
visuomotrice chez le macaque
Abstract: Despite the delays in transmitting the retinal signals to the ocular motor nuclei, the ability of the oculomotor system to intercept and to track a moving visual target is remarkable. Sometimes, the gaze seems to be locked on the physical position (here and now) of the moving object. The aim of this work was to better understand the extrapolation involved in the ocular motor reactions produced in response to the motion of a visual target, before or during its occurrence, and after it has disappeared. In a first study, we describe the effect of the repeated presentation of a visual target that always moves in the same direction on saccadic and pursuit eye movements. The absence of anticipatory movement can be explained by the fact that our monkeys have not been sufficiently trained to emit such responses, in which case anticipatory movements should not be considered as a marker of higher cognitive functions but as the mere result of a habit. In a second neurophysiological study, we describe the temporal evolution and the limit of the influence of visual motion signals on the saccadic system after a transient perturbation applied in the deep superior colliculus by electrical stimulation. This study allowed us to characterize the moment when the visual signals at the origin of the visuomotor extrapolation reach a limit.