[1] Univ Cambridge, Dept Psychol, Cambridge, England
[2] Univ Cambridge, MRC, Cambridge, England
[3] Univ Cambridge, Wellcome Trust Behav & Clin Neurosci Inst, Translat & Cognit Neurosci Lab, Cambridge, England
[4] Salk Inst Biol Studies, Genet Lab, La Jolla, CA 92037 USA