A Simple Neural Decoder and its Motivation

I will talk about two related projects. The first arose as an attempt to answer the following question: How do neural populations in the cortex keep track of sensory signals, separating them from noisy ongoing activity? We demonstrate that sensory signals are encoded more reliably in low-dimensional subspaces defined by correlations between neural activity in primary sensory cortex and upstream sensory brain regions. We analytically show that these correlation-based coding subspaces can reach optimal limits as noise correlations between cortex and upstream regions are reduced, and that this principle generalizes across diverse sensory stimuli in the olfactory system and the visual system of awake mice.  

Second, I will describe the observations that motivated that project, on the difference in the olfactory response between inhale and exhale. This difference is evident early in the olfactory pathway, and we hypothesize that it arises in part because of fluid mechanical forces in the nasal cavity. I will show how we are constructing a phase preference map for mechanical forcing and exploring how this adapts to modifications of the breath cycle. This is joint work with Cheng Ly (Virginia Commonwealth U), Woodrow Shew (U Arkansas), and our trainees.