3:30–4:30 pm KPTC 106
Physics Colloquium Series
Thursday, February 2, 2024, 3:30 PM, KPTC 106
5720 S. Ellis Avenue
Brent Doiron, Director, Grossman Center for Quantitative Biology and Human Behavior, University of Chicago
"Heterogeneity and dimension in recurrent neuronal networks"
Abstract
We will discuss two distinct features of neuronal response. First, neuronal activity is very heterogeneous -- in response to a specific stimulus or behavior some neurons emit many action potentials, and many others are relatively silent. heterogeneous the distribution of trial-averaged responses, the lower the effective dimension of population trial-to-trial covariability. This surprising prediction is tested and validated using multiple population datasets from numerous brain areas in both non-human primates and mice. We present a simple theory whereby a more heterogeneous neuronal code leads to better fine discrimination performance through a lowering of the dimension of population covariability. In line with this result, we show that neural populations across the brain exhibit both more heterogeneous mean responses and lower-dimensional fluctuations when the brain is in more heightened states of information processing. In sum, we present a key organizational principle of neural population response that is widely observed across the nervous system and acts to synergistically improve population representation.