Two types of phase correction mechanism involved in synchronized tapping

We clarify internal phase correction mechanisms affecting timing control in a synchronization tapping task. Synchronization error (SE) was directly controlled within 450–1800 ms of the inter stimulusonset interval (ISI) with our experimental method. Two types of internal phase correction mechanism became evident. The first showed a strong negative correlation between SE change and change in inter taponset interval (ITI), suggesting a simple negative feedback mechanism. This correlation was observed under all ISI conditions. The second type showed a larger response with a low negative correlation and was observed only with long (1200–1800 ms) ISIs. Only the second mechanism was inhibited in a dual task condition. These results suggest that there are two types of internal phase correction mechanism.