Propofol differentially modulates consolidation of schema-congruent and -incongruent memory

Congruency of newly learned information with previous knowledge (i.e. a mental schema) leads to facilitated encoding and rapid integration into neocortical memory networks. It is less known whether this is associated with a differential involvement of the hippocampus in consolidation of schema-congruent and -incongruent information. Here, we used the GABAA-ergic anesthetic propofol to transiently modulate hippocampal neural activity shortly after encoding of schema-congruent and -incongruent information in human patients. We found a significant difference in memory of schema-congruent and -incongruent words in patients that was absent in controls. This effect was driven by a benefit for schema-congruent words, thus suggesting that propofol administration facilitated consolidation of previously encoded schema-congruent items. Our results suggest that schema-congruency of newly learned information significantly modulates involvement of hippocampus-dependent networks during memory consolidation. They further support the hypothesis of a competitive interaction between hippocampus and extra-hippocampal networks during early memory consolidation.