Stress impairs the reconsolidation of autobiographical memories.

Stress enhances memory consolidation, in particular for emotional material. When reactivated, consolidated memories return to a fragile state again and thus require another period of stabilization, called reconsolidation. Rodent studies suggest that memory reconsolidation is impaired by stress. Here we examined in healthy humans the effect of stress on the reconsolidation of autobiographical memories. Participants recalled positive, negative and neutral episodes from their recent past and were afterwards exposed to a stressor (socially evaluated cold pressor test) or a non-arousing control condition. Additional groups of participants were exposed to the stressor without prior memory reactivation or were neither stressed nor asked to recall episodes from their past. Stress after memory reactivation impaired the memory for the neutral episodes 1week later whereas the subsequent memory for the emotional episodes was not affected by stress after reactivation. Reactivation per se or stress without prior memory reactivation had no effect on memory performance. These findings suggest that the effect of stress on memory reconsolidation is opposite to the stress effect on memory consolidation supporting the view that consolidation and reconsolidation are distinct processes. Copyright 2010 Elsevier Inc. All rights reserved.