Characterization of Memory Strengthening Due to Reconsolidation in Episodic Memories

BERON JUAN CRUZ; BAVASSI, LUZ; PEDREIRA MARIA EUGENIA; FERNÁNDEZ RODRIGO S

Otro; Reunion de BIología del Comportamiento del Cono Sur; 2023

Memory reconsolidation is the mechanism by which consolidated memories are updated in strength and/or content. Thus, memory reactivation can enhance the retention of reactivated items at long delays. An underlying hypothesis to these findings suggests that reconsolidation would be “reactivation specific”, implying that only the reactivated elements after consolidation would be susceptible to modifications. However, episodic memories are intrinsically associative, which implies that they are integrated into interconnected- networks between its elements and the acquisition context. Reactivation of certain elements of the target memory should therefore affect elements that were not reactivated but are associated through acquisition context. Our goal was to study the extent of the strengthening due to reconsolidation, that is, to see whether it affects not reactivated elements. To test this hypothesis, we conducted a 3-day study. On day-1, subjects learned face-name pairs (target memory) along with the interleaved presentation of common use objects (peripheric elements). Subjects were instructed to learn the names and between these presentations they were asked to make a judgment call on a certain aspect of the object shown. On day-2, two types of reminders of the target memory were used. The group called RC received a reminder with prediction error that leads to reconsolidation, and the other group, RX, received a reminder that doesn’t involve reconsolidation. On day-3 both the target and peripheric elements of the memory were evaluated. As expected, the memory for face-names was strengthened in group RC, but not in RX. More importantly, we found that the RC group showed better recognition of the new objects (peripheric memory) than the RX one and also showed greater sensitivity at discriminating between conditions. In conclusion, strengthening of the episodic memory as a result of RC reactivation-reconsolidation didn’t circumscribe to the directly reactivated target elements, it also affected peripheric elements that weren’t reactivated but were part of the initial acquisition context.