Neurophysiological markers of asynchronies in a finger tapping task

LUZ BAVASSI; JUAN KAMIENKOWSKI; MARIANO SIGMAN; RODRIGO LAJE

Córdoba

Congreso; XXVIII Congreso de la Sociedad Argentina de Investigación en Neurociencias & Reunión Satélite: ?Bases Neurales de la Conducta: Neuroetología y Neurobiología de la Memoria en el Cono Sur?; 2013

Sensorimotor synchronization (SMS) is a form of referential behavior, mostly specifically human, in which an action is coordinated in time with a predictable external stimulus. Music and dance are archetypical SMS behaviors; yet, the neural bases of the synchronization ability remain unknown, even in the simpler, paradigmatic task of finger tapping to a metronome. We make a step towards the identification of the neurophysiological markers of SMS by recording high-density EEG event- related potentials and the concurrent behavioral response-stimulus asynchronies (time difference between each response and the corresponding stimulus) during a paced finger-tapping task, both isochronous and with temporal perturbations. Using Principal Component Analysis, we found an asymmetry between the traces for advanced and delayed responses to the stimulus; the second principal component encodes the higher-level percept of asynchrony 110 ms after the current stimulus for both types of tone sequences. Furthermore, its amplitude past 300 ms after the stimulus predicts the asynchrony magnitude at the next response. Our results suggest that the correction of a large asynchrony in a periodic task and the recovery of synchrony after a perturbation could be driven by similar neural processes, and that the neurophysiological processing of synchronization errors is performed within a fixed-duration interval after the stimulus.