1. Laboratory of Neuroscience; Graduate School of Pharmaceutical Sciences, Hokkaido University; Sapporo 060-0812 Japan
2. Human Interface Laboratory, Department of Advanced Information Technology, Faculty of Information Science and Electrical Engineering; Kyushu University; Fukuoka 819-0395 Japan
3. Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science; Hokkaido University; Sapporo 001-0021 Japan