Cognitive processes are disentangled at cortex-wide scales

Abstract

Most decisions involve multiple cognitive processes. Recent findings suggest that these processes are distributed across the cortex1-21, but that single regions implement them via orthogonal population-activity patterns14,21-33. How are these local geometries combined across the cortex? Here, we designed a virtual-navigation task for mice that dissociates the accumulation and short-term memory of sensory evidence, and choice. Combining dimensionality reduction and decoding models with cortex-wide widefield Ca2+ imaging, we observed distributed but near-orthogonal coding subspaces for these different cognitive processes, and that this geometry breaks down during erroneous choices. Further, only the memory subspace corresponded to a spontaneous activity-timescale hierarchy, suggesting that it co-opts intrinsic circuit properties. Thus, we reconcile previous findings by showing that cortex-wide dynamics supporting distinct cognitive processes are disentangled.