Short-term learning of a visually guided power-grip task is associated with dynamic changes in EEG oscillatory activity C. Kranczioch a,b, * , S. Athanassiou b , S. Shen b , G. Gao b,c , A. Sterr b a Department of Psychology, University of Portsmouth, King Henry Building, King Henry Ist Street, Portsmouth PO1 2DY, UK b Cognitive Neuroscience Research Team, Department of Psychology, University of Surrey, Guildford, UK c Department of Computer Science, University College London, UK Accepted 17 February 2008 Available online 1 April 2008 Abstract Objective: Performing a motor task after a period of training has been associated with reduced cortical activity and changes in oscillatory brain activity. Little is known about whether learning also affects the neural network associated with motor preparation and post move- ment processes. Here we investigate how short-term motor learning affects oscillatory brain activity during the preparation, execution, and post-movement stage of a force–feedback task. Methods: Participants performed a visually guided power-grip tracking task. EEG was recorded from 64 scalp electrodes. Power and coherence data for the early and late stages of the task were compared. Results: Performance improved with practice. During the preparation for the task alpha power was reduced for late experimental blocks. A movement execution-related decrease in beta power was attenuated with increasing task practice. A post-movement increase in alpha and lower beta activity was observed that decreased with learning. Coherence analysis revealed changes in cortico-cortical coupling with regard to the stage of the visuomotor task and with regard to learning. Learning was variably associated with increased coherence between contralateral and/or ipsilateral frontal and parietal, fronto-central, and occipital brain regions. Conclusions: Practice of a visuomotor power-grip task is associated with various changes in the activity of a widespread cortical network. These changes might promote visuomotor learning. Significance: This study provides important new evidence for and sheds new light on the complex nature of the brain processes under- lying visuomotor integration and short-term learning. Ó 2008 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved. Keywords: ERD; Desynchronisation; ERS; Synchronisation; Motor system; Power; Beta-rebound; Visual force-feedback; Coherence 1. Introduction The ability to continuously adapt motor output based on visual feedback requires the integration of activity in a net- work of frontal, parietal and sensorimotor brain regions (Floyer-Lea and Matthews, 2004; Vaillancourt et al., 2003). The electrophysiological signature of visuomotor integration is a decrease in oscillatory activity, in particular in the alpha and lower beta (8–21 Hz) frequency bands (Clas- sen et al., 1998; Rearick et al., 2001). Another variable to which visuomotor integration has been related to is long- range oscillatory neuronal synchronisation in the beta and gamma frequency ranges (13–80 Hz) (Aoki et al., 1999; Babi- loni et al., 2006; Baker et al., 1999; Lee, 2003; Ohara et al., 2000). In particular, the finding of high-frequency synchro- nisation between visual, parietal, and motor cortices (Clas- sen et al., 1998; Roelfsema et al., 1997) suggests that the synchronisation or coherence of neuronal activity across dis- tant brain regions might be the neural mechanism by which visuomotor integration is implemented. 1388-2457/$34.00 Ó 2008 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.clinph.2008.02.011 * Corresponding author. Address: Department of Psychology, Univer- sity of Portsmouth, King Henry Building, King Henry Ist Street, Portsmouth PO1 2DY, United Kingdom. Tel.: +44 (0) 23 9284 6330; fax: +44 (0) 23 9284 6300. E-mail address: conny.kranczioh@port.ac.uk (C. Kranczioch). www.elsevier.com/locate/clinph Clinical Neurophysiology 119 (2008) 1419–1430