Sensorimotor synchronization: the impact of temporally displaced auditory feedback

When subjects are asked to tap in synchrony to a regular sequence of stimulus events (e.g., clicks), performance is not perfect in that, usually, an anticipation of the tap is observed. The present study examines the influence of temporally displaced auditory feedback on the size of this anticipatory error. Whereas earlier studies have shown that this asynchrony exhibits a linear increase in size as a function of an increasing delay in such additional auditory feedback, this study compared the impact of shifting feedback forward in time (i.e., feedback presented before the tap) with that of delayed auditory feedback. Results showed that the impact of feedback displacement on the amount of asynchrony differed for positive and negative displacements. Delayed feedback led to an increase in asynchrony, whereas negative displacements had (almost) no effect. This finding is related to a model assuming that the various feedback components arising from the tap (tactile, kinesthetic, auditory) are integrated to form one central representation, and that the timing of this central representation arises from a linear combination of the components involved.