Atsushi Nambu1, Ichiro Tsuda2, Tatsuya Mima3. 1. Division of System Neurophysiology, National Institute for Physiological Sciences, Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan. Electronic address: nambu@nips.ac.jp. 2. Chubu University Academy of Emerging Sciences, Kasugai, Aichi 487-8501, Japan. 3. The Graduate School of Core Ethics and Frontier Sciences, Ritsumeikan University, Kyoto, 603-8577, Japan.