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Motor performance is accompanied by neural activity in various cortical and sub-cortical areas. This intricate network has to be delicately orchestrated. We analyzed the role of beta synchronization in motor learning using magneto-encephalography combined with electromyography. Cortico-spinal synchronization in the beta band was found to be of particular importance in establishing bimanual movement patterns in the context of a 3:2 polyrhythmic (isometric) force production task. Its dynamics correlated highly with the learning of this complex bimanual motor skill. We submit that the cortical dynamics entrains the spinal motor system by which cortico-spinal beta synchrony serves higher-level motor control functions as primary means of information transfer along the neural axis., (Copyright 2009 Elsevier Inc. All rights reserved.)

We studied the neural changes accompanying the learning of a perceptual-motor task involving polyrhythmic bimanual force production. Motor learning was characterized by an increase in stability of performance. To assess after-effects in the corresponding neural network, magnetoencophalographic and electromyographic signals were recorded and analyzed in terms of (event-related) amplitude changes and synchronization patterns. The topology of the network was first identified using a beamformer analysis, which revealed differential effects of activation in cortical areas and cerebellar hemispheres. We found event-related (de-)synchronization of beta-activity in bilateral cortical motor areas and alpha-modulations in the cerebellum. The alpha-modulation increased after learning and, simultaneously, the bilateral M1 coupling increased around the movement frequency reflecting improved motor timing. Furthermore, the inter-hemispheric gamma-synchronization between primary motor areas decreased, which may reflect a reduced attentional demand after learning.