A Natural Physiological Process
According to the EMDR International Association (http://emdria.org/), no one knows how EMDR works, but it seems to re-start a natural physiological process in a person’s brain, similar to the process that happens during the REM phase of sleep.
During EMDR, you bring troubling memories out of storage and into your current consciousness, and at the same time, you experience some type of alternating bilateral stimulation. This bilateral stimulation could be moving your eyes back and forth while following a therapist’s fingers, a light bar, or a wand…or it could be holding pulsars in your palms that buzz in alternate hands…or it could be the therapist tapping your knees alternately…or it could be hearing alternating sounds through headphones.
During the processing that EMDR initiates, the emotional disturbance associated with a memory is reduced and the memory becomes organized into a story about something that happened to us, but is no longer disturbing us or negatively affecting our current life. The Adaptive Information Processing theory (Adaptive Information Processing) hypothesizes that our brains naturally process disturbing events, but when the disturbance is more than our system can handle, because we are too young, or because the event is too overwhelming, the disturbing event is left in our brain unprocessed. The feelings and beliefs we have as a result of these unprocessed disturbing events are the reason for our difficulties in our present life.
There are a number of hypotheses about how EMDR accomplishes this adaptive information processing. It is also possible that more than one of the hypothesized mechanisms work together to produce the healing effects of EMDR.
One Hypothesis: EMDR is Similar to the Rapid Eye Movement Stage of Sleep
During the Rapid Eye Movement (REM) stage of sleep, our eyes spontaneously move back and forth and our brain processes and organizes events of our lives. One theory of how EMDR works is that it is an artificially induced REM experience.
Another Hypothesis: The Eye Movements Help Both Sides of the Brain to Work Together Better
The bilateral eye movements (or other bilateral stimulation) may help the left and right sides of the brain to synchronize better.
Another Hypothesis: The Eye Movements Disrupt the Way Our Brains Usually Manage Memories
One idea is that the eye movements of EMDR interrupt the physiological response our brain usually has to a traumatic memory, and allows the memory to be processed in a different, healing, way.
Another Hypothesis: The Eye Movements Provide Distraction
The eye movements of EMDR may distract the client enough that the usual anxiety attached to remembering a traumatic event is reduced, allowing the client to process the memory in a healing way.
Another Hypothesis: Memory Reconsolidation
Bruce Ecker and Laurel Hully (who wrote a book called “Unlocking the Emotional Brain: Eliminating Symptoms at Their Roots Using Memory Reconsolidation”) propose the memory reconsolidation theory.
Memory reconsolidation is a type of neuroplasticity where, under the right conditions, a memory is brought out from where it is stored, challenged in just the right way with new learning, and the new learning deletes the old learning by overwriting it. EMDR, as well as some other types of therapies, sets up these conditions and creates transformational change.
The discovery that our brains are capable of this transformation makes it possible to eliminate symptoms, such as depression, anxiety, low self esteem, fear, flashbacks, and anger, rather than just managing them. For many years, psychotherapists believed that memories that were deeply embedded in our brains because of the strong emotion attached to them, could not be changed, but could only be challenged with new information. Clients had to learn to ignore the old learning and put their attention on the new learning. With memory reconsolidation, the disturbing material is permanently changed. EMDR Therapy is one of only 14 therapies that create transformational change in the brain, rather than counteractive change. (Ecker, Ticic, and Hulley, p. 5)