Funamizu, Akihiro http://orcid.org/0000-0001-8085-1048
Kuhn, Bernd http://orcid.org/0000-0002-6852-2433
Doya, Kenji http://orcid.org/0000-0002-2446-6820
Article History
Received: 18 March 2016
Accepted: 8 August 2016
First Online: 19 September 2016
Competing interests
: The authors declare no competing financial interests.