Auditory Bilateral Stimulation Effects on Episodic Memory Retrieval for Fearful Events.

Abstract

Eye Movement Desensitising and Reprocessing (EMDR) has been established as an effective treatment for posttraumatic stress disorder (PTSD), of comparable effect to trauma-based cognitive behavioural therapy. Despite its status as a first-line treatment, the underlying mechanisms are still under investigation. This study, consisting of a non-PTSD sample of mainly undergraduate psychology students (N = 58), investigated the effects of the crucial bilateral stimulation component of EMDR. Employing a between subjects design, 48 participants were randomly allocated into two groups, either receiving alternating- or simultaneous auditory stimuli. The remaining 10 participants were assigned to a separate forced simultaneous group as their scores on the PDS reached clinical levels. Employing the film clip paradigm, positively shown to elicit emotional arousal of fear, participants' recall of film events was tested with both a free narrative recall and a cued recognition multiple choice questionnaire. Significant differences in emotional responses to the film stimulus are commented upon. The experimental hypothesis predicted that participants in the active condition, receiving alternating auditory bilateral stimuli would elicit enhanced memory recall for the film events. The hypothesis was rejected and possible theoretical explanations are discussed.