[1] Harvard Univ, Sch Med, Beth Israel Deaconess Med Ctr, Dept Neurol,Div Behav Neurol, Boston, MA 02215 USA
[2] Univ Connecticut, Dept Physiol & Neurobiol, Storrs, CT 06269 USA
[3] Ecole Normale Super, Lab Sci Cognit & Psycholinguist, F-75230 Paris 05, France
[4] Univ Connecticut, Dept Psychol Behav Neurosci, Storrs, CT 06269 USA