Electroencephalogram Evidence for Memory Suppression: A Systematic Review

Understanding how people forget is one of the fundamental goals of the science of memory. Recent studies indicate that humans can voluntarily regulate awareness of unwanted memories by stopping the retrieval process that would ordinarily bring past experience into awareness. Event-related potential (ERP) research on memory retrieval reveals that electrophysiological effects with specific timing and scalp topography serve as markers of memory processes. This systematic review examines the literature regarding EEG alterations in memory suppression, highlighting their results on electrophysiological indicators. A systematic review from January 2007 to November 2017 was conducted using PubMed, Embase and ScienceDirect databases. As results, 12 studies were eligible for inclusion. Quantitative EEG can be a objective tool for studying the mechanisms involved in memory suppression. There is evidence that a parietal positivity around 400-800ms after cue presentation is an ERP marker of conscious recollection during memory retrieval and a larger N2 deflection during retrieval suppression predicted greater suppression-induced forgetting.