It is not clear how EMDR works because neuroscience researchers are still exploring how the brain works. Therefore, how any method of psychotherapy works has yet to be established definitively. However, there is evidence for an innate information processing system that exists as part of human thinking processes. What research has suggested so far is that when a person is very upset, the brain cannot process information as it normally does. The event that provoked the upset becomes ‘frozen in time’, and ‘stuck’ in the information processing system. When a person remembers this event, the recalling of sights, sounds, smells, thoughts, and emotions can feel as intense as when it actually occurred. Such upsetting memories may have a profoundly negative impact on the way a person sees the world and relates to other people. Present-day incidents and interactions re-stimulate the experience of this upsetting event.
EMDR appears to produce a direct effect on the way the brain processes upsetting material. Researchers have suggested that the eye movements or bilateral stimulation trigger a neurophysiological mechanism that activates an “accelerated information processing system.” Accelerated information processing is a phrase used in EMDR to describe the rapid working through, ‘metabolizing’, of upsetting experiences. Following successful EMDR treatment, the upsetting experiences are worked through to “adaptive resolution”. The person receiving EMDR comes to understand that the event is in the past, realizes appropriately who or what was responsible for the event occurring, and feels more certain about present-day safety and the capacity to make choices. What happened can still be remembered by the person, but with much less upset.
Many types of therapy have similar goals. However, EMDR can be thought of as a physiologically-based therapy that allows a natural healing process to emerge. Clinical reports and some research findings suggest that the eye movements and the specific targeting of information about the upsetting events may permit direct access to the stored pathology in the brain and more rapid working through of disturbance than more conventional forms of therapy.