Finger tapping kinematics in isochronous synchronization: fast and slow phases and error correction

RIERA, PABLO E.; SPIOUSAS, IGNACIO; DELLA MAGGIONER, VALERIA; LAJE, RODRIGO

Ciudad de Buenos Aires

Congreso; 2nd FALAN Congress; 2016

During an externally paced finger-tapping synchronization task, the overall movement can be separated in two phases: a fast one, when the finger moves down, and a slow one when it moves up. In order to achieve average synchronization, the brain implements a largely unknown error correction mechanism that tends to decrease the next synchrony error based on past errors. Previous works have shown that the computation of the error correction takes place mostly during the slow phase, although those studies were limited to relatively slow sequences. In this work we recorded both the time of the tap and the trajectory of the finger in human subjects synchronizing to an isochronous auditory pacing signal (ISI ranging from 200 through 700 ms). As in previous studies, we observed that the error correction takes place mostly during the slow phase, as shown by a significant negative correlation between asynchrony and the subsequent slow phase duration, but only for the slower tempos. The faster tempos (ISI