In this study we attempted to break down short-term effects of electroconvulsive therapy (ECT) on memory into anterograde and retrograde amnesia, and for the latter we again separated short-term store performances from those connected with the long-term store of memory. Our experiments included complicated learning tasks. Although impairment caused by ECT was demonstrable in all three test fields, complicated conditioning experiments stored in the long-term store proved to be most sensitive to the disturbing effect of ECT.