Effects of learning and movement frequency on polyrhythmic tapping performance

This study examined the effect of learning a complex bimanual coordination task at different movement frequencies. 30 subjects performed 5:3 polyrhythmic tapping at either high, medium, or low movement frequency on a rhythmic synchronization task and then reproduced the polyrhythmic pattern repeatedly in the spontaneous task. Analysis showed that practice on the synchronization task qualitatively changed correct responses into anticipatory ones. The synchronization learning of the polyrhythm caused the anticipatory responses and so, may involve memorization of serial positions within the polyrhythm. Also, more anticipatory responses were indicated in performance at the medium and low frequencies than at the high frequency on the synchronization task. In addition, deviations of taps from expected tapping positions were observed in performance of the spontaneous task at the high frequency. These results suggest that the movement frequency qualitatively influenced the learning of this bimanual coordination. Especially at the high frequency, frequent shifts to other coordination patterns occurred on the spontaneous task. This means that the performance at higher frequency is more strongly affected by entrainment between the two hands.