title: High Accuracy Decoding of Dynamical Motion from a Large Retinal Population.
abstract: Motion tracking is a challenge the visual system has to solve by reading out the retinal population. It is still unclear how the information from different neurons can be combined together to estimate the position of an object. Here we recorded a large population of ganglion cells in a dense patch of salamander and guinea pig retinas while displaying a bar moving diffusively. We show that the bar's position can be reconstructed from retinal activity with a precision in the hyperacuity regime using a linear decoder acting on 100+ cells. We then took advantage of this unprecedented precision to explore the spatial structure of the retina's population code. The classical view would have suggested that the firing rates of the cells form a moving hill of activity tracking the bar's position. Instead, we found that most ganglion cells in the salamander fired sparsely and idiosyncratically, so that their neural image did not track the bar. Furthermore, ganglion cell activity spanned an area much larger than predicted by their receptive fields, with cells coding for motion far in their surround. As a result, population redundancy was high, and we could find multiple, disjoint subsets of neurons that encoded the trajectory with high precision. This organization allows for diverse collections of ganglion cells to represent high-accuracy motion information in a form easily read out by downstream neural circuits.
authors.affiliation: Department of Molecular Biology and Neuroscience Institute, Princeton University, Princeton, United States of America; Institut de la Vision, INSERM UMRS 968, UPMC UM 80, CNRS UMR 7210, Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Marre
authors.affiliation: Institute of Science and Technology Austria, Klosterneuburg, Austria.
authors.forename: Vicente
authors.initials: V
authors.lastname: Botella-Soler
authors.affiliation: Department of Psychology, University of Pennsylvania, Philadelphia, United States of America.
authors.forename: Kristina D
authors.initials: KD
authors.lastname: Simmons
authors.affiliation: Laboratoire de Physique Statistique, École Normale Supérieure, CNRS and UPMC, Paris, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Mora
authors.affiliation: Institute of Science and Technology Austria, Klosterneuburg, Austria.
authors.forename: Gašper
authors.initials: G
authors.lastname: Tkačik
authors.affiliation: Department of Molecular Biology and Neuroscience Institute, Princeton University, Princeton, United States of America.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Berry
mesh_terms: D000200:Action Potentials / Q000502:physiology* / Q000528:radiation effects; D000818:Animals; D003198:Computer Simulation; D006168:Guinea Pigs; D008027:Light; D008959:Models, Neurological; D009039:Motion Perception / Q000502:physiology* / Q000528:radiation effects; D009415:Nerve Net / Q000502:physiology* / Q000528:radiation effects; D010775:Photic Stimulation / Q000379:methods; D012165:Retinal Ganglion Cells / Q000502:physiology* / Q000528:radiation effects; D009435:Synaptic Transmission / Q000502:physiology / Q000528:radiation effects; D014562:Caudata; D014785:Vision, Ocular / Q000502:physiology* / Q000528:radiation effects