1. The Institute of Scientific and Industrial ResearchOsaka University 8‐1 Mihogaoka, Ibaraki Osaka 567‐0047 Japan
2. Graduate School of Information SciencesHiroshima City University 3‐4‐1, Ozuka‐Higashi, Asaminami‐ku Hiroshima 731‐3194 Japan
3. Graduate School of MedicineOsaka University 2‐2 Yamadaoka, Suita Osaka 565‐0871 Japan
4. Medical SchoolKochi University Kohasu Oko‐cho, Nankoku‐shi Kochi 783‐8505 Japan
5. Jinmeikai Research Institute for Mental Health 4‐31, Koshimizu, Nishinomiya Hyogo 662‐0864 Japan