During a traumatic event, someone can be so overwhelmed that their brain may be unable to completely process what is happening. As a result a memory can become ‘stuck’, and the person continues to experience this memory as if it is happening now, rather than in the past. Unlike ordinary memories, this memory remains intense and vivid.
EMDR works to help the brain reprocess the memory so that it is no longer so intense. It also helps to desensitise the person to the emotional impact of the memory, so that they can think about the event without experiencing such strong feelings.
During EMDR bi-lateral stimulation of the brain is utilised though, for example, moving their eyes from side-to-side. Some research suggests that EMDR is effective because this dual engagement of the brain allows the person to distance themselves from the memory and begin to process the event in a more manageable way.