Self-Generated Interval Subdivision Reduces Variability of Synchronization with a Very Slow Metronome

SUBDIVISION BY COUNTING HAS BEEN SHOWN TO improve interval discrimination for durations exceeding 1.2 s (Grondin,Meilleur-Wells, & Lachance, 1999). The present study examined whether simple interval subdivision (bisection) reduces variability of synchronization with a slow metronome. Interval durations ranged from 1 s to 3.25 s.Musically trained participants tapped in synchrony with the metronome while: (1) refraining from any subdivision, (2) mentally bisecting each interval, (3) making additional taps at the bisection points (double tempo tapping), or (4) tapping only at the bisection points (anti-phase tapping). In each task, the standard deviation of asynchronies and intertap intervals was found to increase almost linearly with interval duration, but the slope decreased from condition 1 to condition 4. Differences among conditions were nearly absent with intervals of 1 s (roughly consistent with Grondin et al., 1999), but emerged and increased steadily as interval duration increased. In double tempo tapping, anti-phase taps were less variable than in-phase taps and depended less on the immediately preceding taps. The findings are interpreted in terms of multiple temporal references in synchronization, and their potential relevance to musical ensemble playing is pointed out.