. Author manuscript; available in PMC: 2017 Jun 12.
Published in final edited form as: Neural Comput. 2017 Mar 23;29(5):1229–1262. doi: 10.1162/NECO_a_00949
Published under a Creative Commons Attribution 3.0 Unported (CC BY 3.0) license. (http://creativecommons.org/licenses/by/3.0/).