Mathematics Colloquium: Neural coding and decoding: lossy compression and local invariances
3:10 p.m. Neill Hall 5W
Alexander G. Dimitrov
Abstract: Biological sensory systems, and more so individual neurons, do not represent external stimuli exactly. This obvious statement is a consequence of the almost infinite richness of the sensory world compared to the relative paucity of neural resources that are used to represent it. Even if the intrinsic uncertainty present in all biological systems is disregarded, there will always be a many-to-one representation of whole regions of sensory space by indistinguishable neural responses. When noise is included, the representation is many-to-many. One direction of research in sensory neuroscience, espoused by us and others, is to identify and model such regions, with the goal of eventually completely describing neural sensory function as the partitioning of sensory space into distinguishable regions, associated to different response states of a sensory system. In essence, our goal is to quantify the distortion function of a particular biological system. The questions we are trying to elucidate currently include: What information about the external world is represented in patterns of neural activity? How is this information used by the nervous system to process sensory stimuli? I will report on our progress in these directions.