EEG correlates of motor skill learning

Abstract

Motor learning is a vital ability of the human brain in which multiple cortical areas like the primary motor cortex are involved. One way to investigate the fast motor learning brain dynamics is with use of electroencephalography (EEG). This non-invasive and mobile technique records continuous electrical activity on the brain cortex with a high temporal resolution. Although there has been considerable research into motor learning in humans, the mechanisms behind movement acquisition and execution are still largely unknown. A better understanding of motor learning is relevant to treatment and training in neurorehabilitation and sports medicine. The aim of this study was to provide insight into the neurophysiological mechanisms behind motor skill learning compared to motor execution. Motor skill learning is defined as the acquisition of a complex movement sequence by improving accuracy without comprising on speed. To investigate the neurophysiological mechanisms behind motor skill learning, 128-channel EEG was recorded in 20 young, right-handed, healthy participants while performing a motor skill learning task and a motor execution task. With use of adaptive mixture independent component analysis (AMICA), time-frequency analysis and equivalent dipole fitting source localisation, functional neurophysiological correlates of motor skill learning were investigated. Due to an excessive amount of electrical bridged electrodes, 12/20 participants were excluded from further analyses. In the 8 remaining participants, a cluster of independent components of electrical activity was located on the left primary motor cortex. In the motor learning task, lower β-frequency power was found in these components compared to the control task. This suggest that motor execution could be distinguished from motor learning on EEG by means of β activity in the left primary motor cortex. The results of this study can be used for future research on motor skill recovery in rehabilitation, motor learning in sports medicine and research on interventions to enhance motor learning, like non-invasive electrical brain stimulation.