Sensorimotor synchronization: neurophysiological markers of the asynchrony in a finger-tapping task

LUZ BAVASSI; JUAN KAMIENKOWSKI; MARIANO SIGMAN; RODRIGO LAJE

Psychological Research

Springer-Verlag Berlin Heidelberg

Año: 2015 p. 1 - 14

0340-0727

Sensorimotor synchronization (SMS) is a form of referential behavior in which an action is coordinated with a predictable external stimulus. The neural bases ofthe synchronization ability remain unknown, even in the simpler, paradigmatic task of finger tapping to a metronome. In this task the subject is instructed to tap in synchrony with a periodic sequence of brief tones, and the time difference between each response and the corresponding stimulus tone (asynchrony) is recorded. We make a step towards the identification of the neurophysiological markers of SMS by recording high-density EEG event relatedpotentials and the concurrent behavioral response stimulus asynchronies during an isochronous paced finger tapping task. Using principal component analysis, wefound an asymmetry between the traces for advanced and delayed responses to the stimulus, in accordance with previous behavioral observations from perturbation studies.We also found that the amplitude of the second component encodes the higher-level percept of asynchrony 100 ms after the current stimulus. Furthermore, its amplitude predicts the asynchrony of the next step, past 300 ms from the previous stimulus, independently of the period length. Moreover, the neurophysiological processing of synchronization errors is performed within a fixed-duration interval after the stimulus. Our results suggest that the correction of a large asynchrony in a periodic task and the recovery ofsynchrony after a perturbation could be driven by similar neural processes.