Abstract

Several studies have demonstrated that a consolidated memory can be modified after its reactivation, during the process called reconsolidation. Despite the behavioral evidence about the existence of this process in humans, little progress has been made in understanding the brain mechanisms underlying reconsolidation. Our purpose was to investigate the neural signatures of reconsolidated declarative memories. In order to study reconsolidation in humans, it was used a 3-day paradigm. On the first day, participants had to learn the association between 48 pictures and 48 words. On the second day, subjects were randomly assigned to one of four experimental groups: reactivation group, which was exposed to memory reactivation; reactivation + interference group, which was exposed to memory reactivation and immediately after to a second task (learning a new list of pictures and words); interference group, which was exposed only to a new learning; and control, which did not attend to the laboratory that day. On the third day, memory performance was assessed in an old-new associative task while brain activity was recorded. Our preliminary analyses showed that labilization-reconsolidation strengthened declarative memories. However, this effect was partially prevented when a new list of pictures-words was learned during reconsolidation process. These differences were associated with changes in the temporal dynamic and topography of evoked potentials related to memory retrieval.