Taxonomies of Timing: Where Does the Cerebellum Fit In?

Abstract

Recent models of interval timing have emphasized local, modality-specific processes or a core network centered on a cortico-thalamic-striatal circuit, leaving the role of the cerebellum unclear. We examine this issue, using current taxonomies of timing as a guide to review the association of the cerebellum in motor and perceptual tasks in which timing information is explicit or implicit. Evidence from neuropsychological, neurophysiological, and neuroimaging studies indicates that the involvement of the cerebellum in timing is not restricted to any subdomain of this taxonomy. However, an emerging pattern is that tasks in which timing is done in cyclic continuous contexts do not rely on the cerebellum. In such scenarios, timing may be an emergent property of system dynamics, and especially oscillatory entrainment. The cerebellum may be necessary to time discrete intervals in the absence of continuous cyclic dynamics.

Figure 1

The involvement of the cerebellum in subdomains of timing. As suggested by Coull and Nobre [22**], timing can be conducted explicitly or implicitly, in the motor or perceptual domains. Representative tasks are listed for each subdomain, some of which involve the cerebellum (black) and some that do not (red). The cerebellum is associated with all tasks that are based on temporal contexts defined by discrete intervals. In contrast, tasks that do not involve the cerebellum are those in which timing is established or emerges from a continuous cyclic context.