Synchronizing human movement with an external clock source.

Temporal information processing was studied in humans attempting to tap a key in synchrony with a metronome whose base period was subjected to subliminal random changes. Statistical measures of the sequential timing of metronome and key-tap events were compared with similar time series generated by computer-simulated models of synchronization strategies. From this analysis, synchronization appears to be a sensory-dependent second-order recursive process indexed and stabilized by a combination of internal and external resetting events, with at least two independent sources of timing error.