The impact of trauma exposure on explicit and implicit memory.

Objectives

The present study aimed to determine whether explicit and implicit memory systems are modulated by the type of content (neutral, emotional trauma-related and generally-emotional) in sexual abuse victims who did not develop PTSD, compared to non-exposed controls.

Design

A mixed-factorial design with Content (neutral, trauma-related, generally-emotional) as a within-subject variable and Group (victims, controls) as a between-subject variable was used in two experiments.

Methods

In both experiments, participants were required to learn three stories presented orally: a neutral, an emotional trauma-related (sexual abuse) and a generally-emotional story. In Experiment 1, participants' memory was tested with two explicit tasks (free recall and Remember/Know/Guess) and one implicit task (word-fragment completion task). In Experiment 2, a modified version of the word-fragment completion task was presented, followed by an awareness questionnaire to ensure the implicit character of the test.

Results

Victims showed lower performances with neutral contents, relative to controls, in explicit and implicit tasks. However, this difference was not observed with trauma-related contents suggesting this information is preferentially processed by trauma-exposed participants (with increased attentional resources).

Conclusions

Our results show that trauma exposure may itself be associated with implicit and explicit memory alterations, even for individuals who did not develop PTSD.