This work was supported by grants from the Strategic Research Program for Brain Sciences by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, and from the Funding Program for World-leading Innovative R&D on Science and Technology (FIRST) by the Cabinet Office of Japan, to H.O. and E.S., and the MEXT Grant-in-Aid for Young Scientists to N.K. This study was also partly supported by PRESTO of the Japan Science and Technology Agency to E.S. We thank Ms. Reona Kobayashi for her illustration of a common marmoset.