Motor contributions to temporal prediction extend beyond periodic rhythms
TL;DR
Tapping significantly improved timing accuracy for isochronous and decelerating rhythms, demonstrating that strict periodicity is not a prerequisite for motor benefits and that movement-induced delayed expectations during acceleration may override the predictive benefits of motor alignment.
Abstract
The auditory system requires a reliable and rapid tracking of the temporal dynamics of sounds. While moving in sync with a rhythm can improve timing perception, most research has focused on isochronous rhythms, conflating periodicity with predictability. This study aimed to determine whether the benefits of auditory-motor synchronization extend to aperiodic rhythms with predictable temporal structures and to uncover the neural correlates associated with the motor-enhanced benefit in timing performance. Participants listened to periodic (isochronous) and aperiodic (tempo-changing) rhythms while electroencephalography (EEG) was recorded. They imagined the continuation of each rhythm for two beats and judged the timing of a final target sound while either tapping along or listening attentively. Results showed that participants could synchronize their movements across all rhythm types. However, movement differentially affected temporal judgment across rhythms. Tapping significantly improved timing accuracy for isochronous and decelerating rhythms, demonstrating that strict periodicity is not a prerequisite for motor benefits. However, tapping impaired performance for accelerating rhythms. Behavioral evidence, supported by ERP findings, suggests that movement-induced delayed expectations during acceleration may override the predictive benefits of motor alignment. Thus, while the motor system supports general predictive processing beyond periodicity, accelerations and decelerations involve distinct predictive and motor processing demands.