1. Japan Science and Technology Agency ERATO Okanoya Emotional Information Project Wako 3510198 Japan
2. Laboratory for Biolinguistics RIKEN Brain Science Institute Wako 3510198 Japan
3. Graduate School of Arts and Sciences The University of Tokyo Tokyo 1538902 Japan
4. Laboratory for Vocal Behavior Mechanisms RIKEN Brain Science Institute Wako 3510198 Japan
5. Department of Organismic and Evolutionary Biology Harvard University Cambridge MA 02138 USA