Dear Serge, Your approach seems reasonable to me. Alternately you could probably just put the RTs as the magnitude in EV1 but this confounds your task and the correlation with RTs (which in some cases might be useful). Good luck. Joe Joseph Devlin, Ph. D. FMRIB, Dept. of Clinical Neurology University of Oxford John Radcliffe Hospital Headley Way, Headington Oxford OX3 9DU, U.K. Phone: +44 (0)1865 222 494 Fax: +44 (0)1865 222 717 Email: [log in to unmask]