Causal contribution and dynamical encoding in the striatum during evidence accumulation

Abstract

A broad range of decision-making processes involve gradual accumulation of evidence over time, but the neural circuits responsible for this computation are not yet established. Recent data indicates that cortical regions prominently associated with accumulating evidence, such as posterior parietal cortex and the frontal orienting fields, are not necessary for computing it. Which, then, are the regions responsible? Regions directly involved in evidence accumulation should satisfy the criteria of being necessary for accumulation-based decision-making behavior, having a graded neural encoding of accumulated evidence and causal contributing throughout the accumulation process. Here, we investigated the role of the anterior dorsal striatum (ADS) in a rodent auditory evidence accumulation task using a combination of behavioral, pharmacological, optogenetic, electrophysiological and computational approaches. We find that the ADS is the first brain region known to satisfy these criteria. Thus, the ADS may be the first identified node in the network responsible for evidence accumulation.