Underlying neuronal mechanisms of bilateral alternating stimulations in EMDR therapy

Disruption of fear processing seems to be at the core of posttraumatic stress disorders (PTSD). Indeed, mechanisms of fear conditioning, extinction and extinction recall have been found to be disrupted in PTSD patients. We have demonstrated that such deficits (especially fear extinction delay) disappear after EMDR therapy according to behavioral responses as well as psychophysiological measures (skin conductance, response, heart rate). In addition, using fMRI, we observed improvement of amygdala, hippocampus and ventro-medial prefrontal cortex functioning during extinction in PTSD after EMDR as compared to before EMDR therapy. Considering these results, we used the fear conditioning, extinction and recall paradigm to test for the specific effect of bilateral alternating stimulations during extinction to mimic the EMDR therapy. In healthy human subjects as well as in PTSD patients, we found an effect of bilateral alternating stimulations in key structures involved in fear responses reduction (amygdala and the prefrontal cortex) as compared to without bilateral alternating stimulations. The effect of the bilateral alternating stimulations during desensitization phase of the EMDR therapy may rely among others upon the prefrontal cortex and the amygdala.

Conference

English

Stéphanie Khalfa

Khalfa, S. (2016, June). Underlying neuronal mechanisms of bilateral alternating stimulations in EMDR therapy. Research track: Addiction, Depression and Neurobiology. Presentation at the at the 17th EMDR Europe Association Conference, The Hague