Associate Professor of Psychology at the College of Letters, Ritsumeikan University, Kyoto, Japan. BSc from the Department of Biology, University of Tsukuba, Tsukuba, Japan (1984), and a PhD degree (Doctor of Education) from the Institute of Psychology, University of Tsukuba (1991). He has xtensively studied visual illusions including geometric illusions, light illusions, color illusions, motion illusions and stereoscopic illusions.