Cerebellar contributions to action and cognition: Prediction, timescale, and continuity.

The cerebellum is implicated in nearly every domain of human cognition, yet our understanding of how this subcortical structure contributes to cognition remains elusive. Efforts on this front have tended to fall into one of two camps. On one side are those who seek to identify a universal cerebellar transform, a single algorithm that can be applied across domains as diverse as sensorimotor learning, social cognition, and decision-making. On the other side are those who focus on functional specializations tailored for different task domains. In this perspective, we propose an integrated approach, one that recognizes functional specialization across different cerebellar subregions, but also builds on common constraints that help define the conditions that engage the cerebellum. Drawing on recurring principles from the cerebellum's well-established role in motor control, we identify three core constraints: 1) Prediction-the cerebellum performs anticipatory, simulation-based computations; 2) Timescale-the cerebellum generates predictions limited to short intervals; and 3) Continuity-the cerebellum facilitates the manipulation of mental representations in a continuous, but not discrete manner. Together, these constraints define the boundary conditions underlying how the cerebellum supports cognition, and, just as importantly, specify the types of computations that should not depend on the cerebellum.