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Category: Project

Description: A widely used psychotherapeutic treatment for post-traumatic stress disorder (PTSD) involves performing bilateral eye movement (EM) during trauma memory retrieval. However, how this treatment – described as eye movement desensitization and reprocessing (EMDR) – alleviates trauma-related symptoms is unclear. While traditional theories suggest that bilateral EM interferes with concurrently retrieved trauma memories by taxing the limited working memory resources, here we propose that bilateral EM actually facilitates information processing in the brain. In two EEG experiments, we replicated the bilateral EM procedure of EMDR, having participants engage in continuous bilateral EM or receive bilateral sensory stimulation (BS) as a control while retrieving short- or long-term memory. During EM or BS, we presented bystander images or memory cues to probe neural representations of perceptual and memory information. Multivariate pattern analysis (MVPA) of the EEG signals revealed that bilateral EM enhanced neural representations of simultaneously processed perceptual and memory information. This enhancement was accompanied by heightened visual responses and increased neural excitability in the occipital region. Furthermore, bilateral EM increased functional connectivity between the occipital and frontoparietal regions, potentially facilitating the transition from low-level perceptual representation to high-level memory representation. These findings provide evidence for neural facilitation by the bilateral EM intervention and argue for theories that emphasize information transition rather than disruption in the EMDR treatment.