Eye movement desensitization reprocessing

trauma and the brain

How Does Trauma Work?

If you go to the store to get a loaf of bread, you’ll later be able to tell me the story of what you did: “I grabbed my keys and wallet, got into my car, and headed for the store. Boy, I hit every red light. But I finally got there and got the bread. I got home just in time for dinner.” The experience has gone through sensory memory (what you touched, heard, and saw), into your short-term memory (which lasts an average of 20-45 seconds), and then into your long-term memory, allowing you to retrieve it and tell the story later. 

However, when we experience trauma, our brains aren’t able to process information the way they usually do. The part of the brain that handles executive function (called the prefrontal cortex, or PFC) and regulates behavior, thought, and emotion, goes “off-line.” This means the memory of the traumatic experience can’t be filed away in the brain like a regular experience would be. 

If you develop PTSD after being in a car accident, and one day are driving home from the grocery store and hear squealing tires, your brain could retrieve the memory of the accident—and your body would react as if it were happening again. You would tense up, perhaps hit your brakes, perhaps cry out. And you would have absolutely no control over whether or not this memory came up; it is simply a function of the brain. It is not a matter of being “strong enough” to control it. When a trauma takes place, the brain simply reacts.