Phase correction in sensorimotor synchronization with nonisochronous sequences

Phase correction, which is necessary for synchronization of movements with a rhythm, has been studied primarily with isochronous sequences.We used a phase perturbation method to examine phase correction in synchronization with nonisochronous sequences (3:2 interval ratios), using musically trained participants. In isochronous control sequences, the phase correction response (PCR) of the tap following a small phase shift was larger when the intervals were long (600 ms) than when they were short (400 ms). In nonisochronous cyclic two-interval patterns, we found a similar dependence of the PCR on the duration of the interval following a phase shift. In three-interval patterns, however, there was no clear dependence on interval duration. The metrical interpretation of the sequences (downbeat location) had no effect on phase correction. In general, phase correction was as effective with nonisochronous as with isochronous sequences.