The accumulation of sensory evidence is a crucial aspect of perceptual decision-making, and it involves complex neural computations requiring sensory processing, weighing of sensory evidence for or against a decision, as well as short-term memory of accrued evidence. Given this complexity, it is likely that many cortical areas are causally involved in evidence accumulation. However, little is known about which areas are necessary for evidence accumulation; moreover, we do not understand the neuronal circuit mechanisms underlying this important phenomenon. To answer these questions, I am using a novel virtual navigation-based visual accumulation task for head-fixed mice, which I developed in collaboration with other members of the BRAIN COGS team, especially Sue Ann Koay and Ben Engelhard. I am combining the task with a suite of optical techniques to manipulate and record dorsal cortical activity on meso- to large spatial scales, informed by computational models of cognitive behavior. My findings suggest that evidence accumulation engages widespread processes throughout the entire dorsal cortex, with different areas performing different computations.
I am also following up on these results with much more temporally specific inactivations of different cortical areas, in isolation or combination. Combined with modeling, this will help us understand how different cortical areas act in concert to mediate evidence-accumulation-based decisions.