Abstract

For motor control the functional role of neural synchronization within the cortex and between cortex and spinal cord is still under debate as empirical findings often disagree and depend on the task under study. Spectral power strongly fluctuates with performance because it represents (event-related) local (de-)synchronization. Does this imply that cortico-spinal, i.e. long-range synchrony is merely a by-product of local, oscillator activity? Or, should synchrony be seen as an entity on its own, providing additional means for information transfer over longer distances?

Theoretical arguments for distinct roles of local and long-range synchrony find recent empirical support in recordings of motor cortex and muscle activity during motor learning. Cortico-spinal synchronization in the beta band will be shown to be particularly important in establishing bimanual coordination patterns since its gradual changes correlate with the learning dynamics. In consequence, cortico-spinal beta synchrony is likely to serve higher-level motor control functions as primary means of information coding and transfer along the neural axis.