Synchronization of auditory-hand tapping coupling: the effect of aging.

Hand(s)-tapping tasks have been extensively studied in order to characterize the features of sensorimotor synchronization (SMS). These tasks frequently require participants to synchronize their tapping pace to an external, metronome-like sound. The impact of ageing on SMS abilities remains mainly unexplored. Thus, we conducted a series of hand tapping tasks on 15 young adults (YA) and 15 older adults (OA). The tasks included tapping with the dominant hand only (D), with the non-dominant hand only (ND), with both hands simultaneously (SIM), and alternating between the hands (ALT). Participants in each task performed a synchronization-continuation task, in which they had to tap for one minute according to an external sound set at their spontaneous motor tempo (separately identified), and then, after the sound stopped, continue tapping at the same tempo for another minute. Results indicated a set of preserved and degraded tapping behaviors in OA compared to YA. The ALT task produced the most deteriorated tapping performance, followed by the ND task; the other two tasks revealed no difference between the groups. These findings shed more light on how SMS declines across the lifespan and provide some preliminary but important information that may guide rehabilitation and diagnostic procedures.