Complex information processing networks of EEG oscillations during voluntary movements

A complex physical pattern of connections has been widely observed in many real-world systems, including social, biological, and technological networks. This ubiquitous characteristic of complex systems has also been observed in functional/structural networks of the human brain. In this study, we examined complex network topology of EEG-based functional connections while subjects performed voluntary movements. The complex system of the brain networks revealed an ideal balance between efficient information processing of local specialization and global integration, as reflected by small-world index across a wide range of EEG frequency-bands, i.e., theta, alpha, beta, and gamma oscillations. Further, directing subjective experience towards inner processes to voluntary movement altered the information processing of the brain networks wired by gamma oscillations. Brain functional networks demonstrate distinct small-world property depending on the strategy initiating voluntary movements while preserving the ubiquitous network characteristics found in many complex systems. Estimation of this alteration could prove helpful for understanding the brain mechanism of voluntary movements as well as for the evaluation of the efficiency of brain network.