Eye Movement Desensitization and Reprocessing (EMDR) is a therapy used to address adverse life experiences that contribute to problems in daily living. Memory networks are the basis of pathology and health. When an experience is successfully processed (whether positive or negative), it is adaptively stored, integrating with other, similar experiences about self and other. Disruptions to the information processing system due to high arousal states from adverse life experiences result in memories that are inadequately processed and manipulatively stored. In other words, the event was too much for the brain to process at that time. As stimuli/information from the present situation (unconsciously) link to negative experiences in the past, these similarities can trigger a reaction to the present as if it were the same situation as the past.
These inadequately processed memories and their stored components (images, thoughts, emotions, physical sensations, and beliefs) change during reprocessing. Reprocessing takes place when dual attention on a past memory, combined with bilateral stimulation, activates and associate process that allows relevant connections to be made. When reprocessing is successful, the previously disturbing memories are neutralized and affectively integrated with other similar experiences. What is useful is stored, available to inform future experiences; what is no longer adaptive is discarded (such as negative images, feelings, beliefs).
Francine Shapiro, PhD