Auditory dominance in the error correction process: a synchronized tapping study.

The goal of this study was to reveal auditory dominance in the error correction process that operates in the synchronized tapping paradigm. We presented six female subjects with a sound and a flash, alternately and successively. The subjects' task was to tap in synchrony with the sequence of the attended to modality (the target sequence). The inter-onset interval of the target sequence was 996 ms but varied irregularly between 996 - alpha ms and 996 + alpha ms for the distractor sequence. We found that tapping accuracy was influenced by the irregularity of the distractor sequence. As distractor stimuli were temporally separated from target stimuli, auditory-visual integration in timing did not occur in our experiment. Therefore, the irregularity of the distractor sequence must have directly influenced the error correction process in timing and not indirectly by affecting the target sequence to subsequently influence the error correction process. We also found that tapping accuracy was influenced by the irregularity of the auditory distractor, even when the irregularity was unnoticeable, but it was not affected by the irregularity of the visual distractor when the irregularity was unnoticeable, which suggests that the error correction process is located before, or is independent of, the perception of irregularity in timing. We conclude that the error correction process depends more on temporal information from the auditory system than on information from the visual system.