Effects of pregnancy on explicit memory, implicit memory and implicit learning: evidence for a double dissociation

Abstract

Pregnant subjects and a control group were compared on a variety of memory and learning tests. For the pregnant group explicit memory tested by both recognition and recall was unimpaired. Likewise their performance on a motor serial reaction time task was preserved. Implicit memory, as measured by word stem completion, was impaired for the pregnant group. The finding of a dissociation, between explicit memory and implicit memory, and implicit memory and implicit learning, is discussed. Benzodiazepine-like substances are suggested as a possible mechanism for the reported dissociations.