1 Department of Biomedical Engineering, College of Health Science, Korea University, Seoul 136-100, South Korea
2 Center for Neural Science and WCI Center for Functional Connectomics, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea
3 Neuroscience Program, University of Science and Technology (UST), Daejeon 305-350, South Korea
4 KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701, South Korea