Nat. Neurosci. 14, 163–164 (2011); published online 26 December 2010; corrected after print 5 July 2011

In the version of this article initially published, the gender of participants was reversed and the gender of one participant was mislabeled. The correct demographics are 37 female and 21 male participants, with concomitant changes to the values in Table 1. The errors have been corrected in the HTML and PDF versions of the article.