Author:

Keywords:

fMRI, Expertise, Ageing, Musicians

Abstract:

We determined the neural underpinnings of hierarchical timing control (HTC) from whole-brain functional scans collected in 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 tasks (Digit-Symbol, Digit-Span, 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. For complex tasks we found novices relying on posterior cerebellar Lobules (VI + Crus), Intraparietal Sulci, and a parietal-prefrontal network. Location of clusters and activation increases with task complexity point to typical domain-general networks, with demonstrated age-sensitivity particular in prefrontal regions. In contrast, experts relied on specific premotor and SM1 areas and this reliance on specific expert mechanisms was similar across task conditions. To distinguish changes at the brain level in response to short-term practice from those of lifelong expertise we re-tested (including whole brain scans) our participants after six (novices), respectively one (experts) behavioral training sessions. Despite massive improvements in the novice group expert and novice neural mechanisms could still be dissociated.