Enhancement of visuomotor synchronization by a regular pattern of stimulus presentation

Stable synchronization with external auditory/visual events is important for cooperative behavior, such as playing music in an orchestra. One way to enhance synchronization in the auditory domain is by inserting different tones between tones to synchronize. Synchronized tapping for every other tone or more (1: n tapping) is less variable than that for each tone (1:1 tapping). This phenomenon is called the "subdivision benefit," which is interpreted as that additional temporal references by subdivided tones make synchronization more stable. However, it is unclear whether visuomotor synchronization becomes more stable by subdividing a stimulus sequence. To clarify this, the present study compared 1:3 tapping with a sequence of three-picture patterns and 1:1 tapping with a single picture repetition. When the inter-tap interval (ITI) was 1200 ms or more, the tapping variability showed a subdivision benefit, irrespective of the position of the pictures (1st, 2nd, or 3rd picture) in the three-picture pattern. However, when the ITI was <1000 ms, subdivision did not have any significant effect. These results imply that the subdivision benefit is due to the additional temporal reference provided by the subdivided stimuli, and the benefit depends on the ITI length.