A crucial step in timing research is to isolate clock components from other sources of temporal variability. Significant progress has been made both behaviorally and neurologically, using elaborate experimental designs that separate timing mechanisms from motoric sensory and mnemonic processes. Marked similarities between the temporal characteristics of the clock in perception and production tasks implicate a common timing system. Similar conclusions can be reached from clinical studies, indeed individuals with neocerebellar damage are impaired at discriminating and reproducing short intervals. However, other patient populations, especially those with disorders affecting the basal ganglia, also exhibit deficits in timing tasks. It therefore appears that temporal computation may be distributed throughout the brain with specific roles for different neural structures.