Nat. Neurosci. 16, 777–779 (2013); published online 25 June 2013; corrected after print 1 July 2013
In the version of this article initially published, Mihaela D. Iordanova's affiliation was given as the Department of Psychology, University of Maryland Baltimore County instead of the Department of Anatomy and Neurobiology, University of Maryland, School of Medicine, and the former was omitted from Geoffrey Schoenbaum's affiliations. The error has been corrected in the HTML and PDF versions of the article.