Effects of Psychosocial Stress on Episodic Memory Updating

Abstract

The malleable nature of human memory has been the focus of considerable research in recent years. Memory is no longer viewed as permanent and non-modifiable. When a consolidated memory is reactivated it becomes labile and modifiable again. Recently, updating of reactivated memory has been demonstrated, manifesting as the addition of new but relevant information. New, similar, information that is acquired in a separate learning episode is embedded within the original memory. We were interested in exploring the effects of psychosocial stress on this episodic memory updating. Individuals were stressed prior to reactivation of the original memory (Experiment 1) or prior to the onset of reconsolidation of the original memory (Experiment 2). Based on prior research, we hypothesized that in both experiments stress would impair memory updating. In Experiment 1, stress reduced memory updating, but this effect did not achieve statistical significance. In Experiment 2, stress impaired the consolidation of an `updated' memory. These findings not only corroborate stress-induced impairments of memory but also shed light on the possible consequences of impaired memory updating. We discuss the relevance of these experimental results in the context of problem solving.