[1] RIKEN, MIT, Picower Ctr Learning & Memory, Ctr Res Neurosci, Cambridge, MA 02139 USA
[2] MIT, Dept Brain & Cognit Sci, Cambridge, MA 02139 USA
[3] Johns Hopkins Univ, Mind Brain Inst, Baltimore, MD 21218 USA
[4] Johns Hopkins Univ, Dept Neurosci, Baltimore, MD 21218 USA