The work presented here was completed by the author’s group at ATR (Jianwu Dang, Satoru Fujita, Seiji Adachi, Tatsuya Kitamura, Hironori Takemoto, Sayoko Takano, Yukiko Nota, Emi Murano, and Hiroyuki Hirata) and by our colleagues at ATR Brain Activity Imaging Center (Shinobu Masaki, Yasuhiro Shimada, Ichiro Fujimoto, and others). This research was conducted as part of “Research on Human Communication” with funding from the National Institute of Information and Communications Technology.