Nat. Neurosci. 7, 1299–1301 (2004)

The affiliation given for Sylvie Duval was incorrect. The paper should have stated her affiliations as follows: Institut des Sciences Cognitives, CNRS, 67 Boulevard Pinel, 69675 Bron, France, and Department of Neuromotor Physiology, IRCCS- Fondazione Santa Lucia, Via Ardeatina 306, 00179 Roma, Italy. The authors regret the error.