Why the Eye Movements? How EMDR Is Thought to Work

One of the most common questions about EMDR is also the most basic: why would moving your eyes from side to side help with trauma? It sounds almost too simple, and for years it fueled skepticism about the therapy, even as clinical trials showed it worked. So what is actually going on? In an EMDR session, a person brings a distressing memory to mind while at the same time doing a second task, usually following the therapist's moving hand with their eyes, though hand taps or alternating tones work too. The leading explanation for why this helps is known as working memory theory. Our working memory, the mental workspace we use to hold information in mind, has a limited capacity. Vividly recalling a memory draws on it, and so does tracking a moving target. When you do both at once, they compete for the same limited resources, and the memory comes to mind in a fainter, less vivid, and less emotional form. Recalled this way many times over a session, the memory is gradually re-stored with less of its original emotional charge. This idea is well supported by experiments. Studies dating back to the 1990s have repeatedly shown that recalling a negative memory while making eye movements makes it less vivid and less distressing than recalling it without them. A systematic review by Rubén Landin-Romero and colleagues, published in *Frontiers in Psychology* (2018), examined 87 studies covering psychological, physiological, and brain-based explanations. It found reasonable support for the working memory account, and noted that eye movements specifically tended to produce a faster and moderately greater benefit than other forms of stimulation. Working memory is not the only theory. Some researchers point to a resemblance between EMDR's rhythmic stimulation and the eye movements of REM sleep, when the brain naturally works through emotional memories. The mechanism is not fully settled, and is likely to involve several overlapping processes. One point most researchers agree on, though, is important for anyone considering the therapy: EMDR does not erase memories. The event still happened, and you will still remember it. What changes is the vividness and emotional intensity, so that the memory begins to feel like a memory, rather than something happening all over again. *Sources:* - *Landin-Romero, R., Moreno-Alcázar, A., Pagani, M., & Amann, B. L. (2018). How Does Eye Movement Desensitization and Reprocessing Therapy Work? A Systematic Review on Suggested Mechanisms of Action. Frontiers in Psychology, 9, 1395.* - *van den Hout, M. A., & Engelhard, I. M. (2012). How does EMDR work? Journal of Experimental Psychopathology, 3(5), 724–738.*