1. Center for Human Development and Family Science Department of Pediatrics and Neonatology Nagoya City University Graduate School of Medical Sciences Nagoya Aichi 467‐8601 Japan
2. Department of Paediatrics and Child Health, Centre for Developmental and Cognitive Neuroscience Kurume University School of Medicine Kurume Fukuoka 830‐0011 Japan
3. Centre for the Study of Medical Education Kurume University School of Medicine Kurume Fukuoka 830‐0011 Japan
4. Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine National Cheng‐Kung University Tainan 70457 Taiwan
5. Central Research Laboratory Hamamatsu Photonics K.K. Hamamatsu Shizuoka 434‐8601 Japan
6. Yanagawa Institute for Developmental Disabilities, International University of Health and Welfare Yanagawa Fukuoka 832‐0813 Japan
7. Graduate School of Information Sciences Tohoku University Sendai City Miyagi 980‐8579 Japan