What is EMDR?

EMDR stands for Eye Movement Desensitisation and Reprocessing therapy, a name that is not entirely accurate nowadays but has stuck since the early days of its development. In the 1980s, Dr. Francine Shapiro discovered by accident that rapid eye movements could improve distress. While we have long known that this works, it is only recently that we have really understood the mechanisms of EMDR.

How does EMDR work?

Different areas of the brain are activated in different situations. In a traumatic experience, or one that evokes intense negative emotions, the amygdala, or "fear and anxiety" centre of the brain, becomes activated. The amygdala works as a sort of seesaw with other areas of your brain, namely the hippocampus, which is responsible for memory formation and emotional processing, and the prefrontal cortex, which is responsible for reasoning, emotional regulation, and logic. So when the amygdala is highly activated, as in a traumatic experience, the hippocampus and prefrontal cortex are deactivated. This is why traumatic memories are so different to "normal" memories - they are disjointed, they are vivid, and they are difficult to square with what your logic might tell you.

EMDR uses bilateral stimulation of the brain, typically through eye movements (there are alternatives), to reprocess traumatic memories so that they feel "distanced" (i.e., not so vivid and more like normal memories); they are desensitised (i.e,., they no longer evoke a strong emotional reaction); and to effect belief change (i.e., you are no longer stuck in the old, distressed way of thinking and can integrate a more rational, helpful belief with the memory).

How does the bilateral stimulation do this? There are things we still don't know, but there is mounting evidence that at least two mechanisms are critical. The first is the taxation of working memory. That is, EMDR requires your brain to keep track of multiple things at once, allowing a person to hold a traumatic memory in mind while suppressing activation of the amygdala and, therefore, strong emotions. Suppression of the amygdala allows your hippocampus and prefrontal cortex to "come online", so to speak. The second mechanism is to do with the eye movements themselves. We think that this helps with memory reprocessing and learning consolidation in the same way that REM (rapid eye movement) sleep is critical for learning.

In short, while EMDR can seem like some sort of voodoo or hypnosis, it is actually well grounded in cutting edge neuroscience.