NeuroMat webinar
When: June 8, at 10 am (S.Paulo local time) / 3pm (Nice local time)
Speaker: Bruno Cessac, head of Biovision Lab
Institution: Université Côte d´Azur, Inria/Biovision team and Neuromod Institute
Title: The retina as a dynamical system
Abstract: The retina is the entrance to the visual system. The development of new technologies and experimental methodologies (MEA, 2-photon, genetic engineering, pharmacology) and the resulting experiments have made it possible to show that the retina is not a mere camera, transforming the flow of photons coming from a visual scene in sequences of action potentials interpretable by the visual cortex. It appears, in contrast, that the specific and hierarchical structure of the retina allows it to pre-process visual information, at different scales, in order to reduce redundancy and increase the speed, efficiency, and reliability of visual responses.
This is particularly salient in the processing of motion, which is the essence of what our visual system receives as input: there are no static objects since our body, our head, our eyes are constantly on the move. The retina is thus a fascinating object and its study opens the door to better understand how our brain processes information (here, visual information).In this talk, we will adopt a specific, modeler, point of view. The retina is a specific organ, with specific neurons and circuits, rather different from their cortical counterparts, leading to specific questions – requiring specific techniques – that can be addressed in the realm of dynamical systems theory. More precisely, the retina is a high dimensional, nonautonomous dynamical system, layered and structured, with nonstationary and spatially inhomogeneous entries (visual scenes). It is, therefore, necessary to go, as much as we can, beyond the assumption of stationarity.After a brief introduction on retina’s structure and dynamics where we will stick as much as possible (for a modeler) to biology, we will present some results where dynamical systems-, bifurcations-, and ergodic-theory provide useful insights on retinal behavior and dynamics: retinal waves, motion anticipation and spatio-temporal correlations induced by a stimulus.
This is particularly salient in the processing of motion, which is the essence of what our visual system receives as input: there are no static objects since our body, our head, our eyes are constantly on the move. The retina is thus a fascinating object and its study opens the door to better understand how our brain processes information (here, visual information).In this talk, we will adopt a specific, modeler, point of view. The retina is a specific organ, with specific neurons and circuits, rather different from their cortical counterparts, leading to specific questions – requiring specific techniques – that can be addressed in the realm of dynamical systems theory. More precisely, the retina is a high dimensional, nonautonomous dynamical system, layered and structured, with nonstationary and spatially inhomogeneous entries (visual scenes). It is, therefore, necessary to go, as much as we can, beyond the assumption of stationarity.After a brief introduction on retina’s structure and dynamics where we will stick as much as possible (for a modeler) to biology, we will present some results where dynamical systems-, bifurcations-, and ergodic-theory provide useful insights on retinal behavior and dynamics: retinal waves, motion anticipation and spatio-temporal correlations induced by a stimulus.
Video of the presentation: https://www.youtube.com/watch?v=BJ-5O-HJg_Y
