LETTER Communicated by Mehdi Khamassi The Basal Ganglia Optimize Decision Making over General Perceptual Hypotheses

The basal ganglia are a subcortical group of interconnected nuclei in-volved in mediating action selection within cortex. A recent proposal is that this selection leads to optimal decision making over multiple alternatives because the basal ganglia anatomy maps onto a network implementation of an optimal statistical method for hypothesis testing, assuming that cortical activity encodes evidence for constrained gaussian-distributed alternatives. This letter demonstrates that this model of the basal ganglia extends naturally to encompass general Bayesian sequen-tial analysis over arbitrary probability distributions, which raises the proposal to a practically realizable theory over generic perceptual hypotheses. We also show that the evidence in this model can represent either log likelihoods, log-likelihood ratios, or log odds, all leading pro-posals for the cortical processing of sensory data. For these reasons, we claim that the basal ganglia optimize decision making over general per-ceptual hypotheses represented in cortex. The relation of this theory to cortical encoding, cortico-basal ganglia anatomy, and reinforcement learning is discussed.