Cortico-striatal Representation of Time in Animals and Humans

Interval timing in the seconds-to-minutes range is crucial to learning, memory, and decision-making. Recent findings argue for the involvement of cortico-striatal circuits that are optimized by the dopaminergic modulation of oscillatory activity and lateral connectivity at the level of cortico-striatal inputs. Striatal medium spiny neurons are proposed to detect the coincident activity of specific beat patterns of cortical oscillations, thereby permitting the discrimination of supra-second durations based upon the reoccurring patterns of subsecond neural firing. This proposal for the cortico-striatal representation of time is consistent with the observed psychophysical properties of interval timing (e.g. linear time scale and scalar variance) as well as much of the available pharmacological, lesion, patient, electrophysiological, and neuroimaging data from animals and humans (e.g. dopamine-related timing deficits in Huntington's and Parkinson's disease as well as related animal models). The conclusion is that although the striatum serves as a 'core timer', it is part of a distributed timing system involving the coordination of large-scale oscillatory networks.