Effect of time delay on performance and timing control in dyadic rhythm coordination using finger tapping

In musical ensembles, people synchronise with each other despite the presence of time delays such as those related to sound transmission. However, the ways in which time delays in synchronisation are overcome remain unclear. This study aimed to investigate the basic characteristics and mechanism of synchronisation with time delays using a dyadic synchronisation-continuation finger-tapping task with time delays ranging from 0 to 240 ms. The results reveal that synchronisation performance improved under time delays of 40-160 ms compared with in the other conditions. This tolerance to the time delay could have been because such a delay allowed both participants in each pair to tap before receiving the stimuli from their partner, as seen in synchronisation with a constant-tempo metronome. In addition, the dependency of the timing control on the partner's previous inter-tap interval decreased at a time delay of 80 ms, relating to the fact that the acceleration and deceleration of the tapping tempo reduced under certain time delays, while the synchronisation performance improved. Uncertainty in the timing of the partner's stimulus could induce greater anticipatory responses, making it possible to tolerate longer time delays in dyadic finger-tapping tasks.