The talk will focus on decision-making under conditions of uncertainty. I will present a new task in mice designed to probe neural processes leading up to a decision, based on noisy sensory evidence and prior task knowledge, and report findings of cortex-wide dynamics during the task, which identify the premotor neocortex as representing the animal’s state of belief prior to choice commitment. I will discuss a conceptual framework that can explains these findings, and finish on discussion of potential neural mechanisms contributing to activation premotor neocortex, such as the deep nuclei of the cerebellum