Amnesic patients were able to retrieve an object hidden at an initial location after a brief delay, but subsequently failed to retrieve an object at a new location, and instead searched for it at the old place. This phenomenon, which we call mnemonic precedence, resembles the AB error that has been observed in 8-10-month-old infants. The parallel performance of amnesics and infants on object search tasks is consistent with the hypothesis that memory deficit, rather than defective object concept, plays a major role in the AB error. The influence of memory processes on tests of symbolic representation is discussed.