Transient medial prefrontal perturbation reduces false memory formation

Abstract

Knowledge extracted across previous experiences, or schemas, benefit encoding andretention of congruent information. However, they can also reduce specificity and augmentmemory for semantically related, but false information. A demonstration of the latter isgiven by the DeeseeRoedigereMcDermott (DRM) paradigm, where the studying of wordsthat fit a common semantic schema are found to induce false memories for words that arecongruent with the given schema, but were not studied. The medial prefrontal cortex(mPFC) has been ascribed the function of leveraging prior knowledge to influence encodingand retrieval, based on imaging and patient studies. Here, we used transcranial magneticstimulation (TMS) to transiently perturb ongoing mPFC processing immediately beforeparticipants performed the DRM-task. We observed the predicted reduction in false recallof critical lures after mPFC perturbation, compared to two control groups, whereas verid-ical recall and recognition memory performance remained similar across groups. Thesedata provide initial causal evidence for a role of the mPFC in biasing the assimilation ofnew memories and their consolidation as a function of prior knowledge.