EMDR therapy seems to have a direct effect on the way that the brain processes information. Normal information processing is resumed, so following a successful EMDR therapy session, a person no longer relives the images, sounds, and feelings when the event is brought to mind. You still remember what happened, but it is less upsetting. Many types of therapy have similar goals. However, EMDR therapy appears to be similar to what occurs naturally during dreaming or REM (rapid eye movement) sleep. Therefore EMDR therapy can be thought of as a physiologically based therapy that helps a person see disturbing material in a new and less distressing way.
*Credit: EMDRIA