Author:

Abstract:

Rhythmic timing is a key component of musical expertise as well as part of the normal behavioral repertoire. Effects of task complexity and adult-age related changes in timing accuracy are explained by the Hierarchical Timing Control model (HTC), which distinguishes low-level timing, sequencing, and task-set control levels. To determine the neural substrates of HTC levels we collected whole-brain functional scans from four groups of young (M=26.09 yr.) and older (M=61.62 yr.) professional musicians and age-matched novice controls (N=20 per group). Participants tapped rhythmic sequences with a wrist orthesis while lying supine in the scanner. Behavioral data showed the expected age x expertise interaction with older experts clearly outperforming young novices. Results from far-transfer task (Go-NOGo) indicated experts and novices were similar regarding domain-general processing speed, working memory, and cognitive control. fMRI data revealed a typical sensorimotor network for low-level timing, a parietal-premotor network for sequencing, and extensive prefrontal activation for the most complex timing tasks in novices. Low-Level timing activation was similar in experts, however, for complex rhythm tasks experts relied on specific premotor and SM1 areas. Results support the HTC model at the neural level and they dissociate expert and novice neural mechanisms.