The Neuroscience of Traumatic Memories

What if I told you that your body relives trauma when you recall it? 

Whether it’s a heartbreak or a lost job, most of us carry sad memories. But for those who have experienced trauma or are living with Post-Traumatic Stress Disorder (PTSD), traumatic memories are fundamentally different in the brain. A study from researchers at Yale School of Medicine and Icahn School of Medicine at Mount Sinai, published in Nature Neuroscience* in 2023, found that the brain processes traumatic memories very differently from other painful memories.

With the use of brain imaging, researchers discovered that the brain processes traumatic memories as "present-tense" fragments rather than organized stories from the past. So when you recall a traumatic event, your brain can enter the same neurological state it was in when the event originally happened, instead of recognizing it as something that occurred in the past.

The Hippocampus

To understand the study, we first have to look at the hippocampus. The hippocampus is the brain’s filing cabinet. Its job is to take your experiences, organize them into a chronological narrative, and file them away in the past section of your memory.

When we remember a sad but non-traumatic event, such as the loss of a pet or a difficult breakup, the hippocampus works normally. It recognizes the memory as a story that has a beginning, middle, and end. 

The Findings: Traumatic vs. Sad

The researchers, led by Ilan Harpaz-Rotem, PhD, and Daniela Schiller, PhD, asked 28 participants with PTSD to recount three types of memories while undergoing an fMRI scan:

1. Neutral memories (e.g., a calm day at the park).

2. Sad memories (e.g., the death of a family member).

3. Traumatic memories (e.g., the specific events that caused their PTSD).

The results reflect that our brain responds significantly differently when we recall neutral and sad memories versus traumatic memories. When participants recalled sad memories, their hippocampus showed that their brain was processing the memory like a coherent story.

However, when they recalled traumatic memories, the hippocampus’s activity patterns were disorganized and lacked the typical "narrative" structure. As the study notes:

Our main finding... supports the idea of a profoundly separate cognitive experience in the reactivation of traumatic memories."  - Dr. Ilan Harpaz-Rotem

Instead of being filed away as a story in the past, traumatic memories exist as disconnected and nonlinear fragments of sensory information. The brain doesn't realize the event is over since the hippocampus fails to organize the fragments of it. That is to say, those who recalled traumatic experiences entered a neurological state that displayed the event as still currently happening. This explains why people with PTSD often experience flashbacks where they feel like they are reliving the trauma in the present moment. In the words of the researchers, these memories are "subjugating the present moment to evade the comfort of belonging to the past."

So what does this mean for trauma treatment?

This research validates what many trauma survivors feel: you can't just "get over" a traumatic memory. It proves how talking about your traumatic memories in depth has the potential of retraumatizing you, as it exposes you to that experience all over again. 

The goal of many PTSD therapies is to not just talk about the event but to reprocess it neurologically. Modalities such as Eye Movement Desensitization Reprocessing (EMDR), Somatic Experiencing, Internal Family Systems (IFS), Prolonged Exposure, or Cognitive Processing Therapy are used to help the clients take fragmented, disturbing "present-tense" images and weave them into a coherent narrative with a beginning, middle, and end. By doing so, the hippocampus can finally file the event into the past.

If this resonates, you can find more resources on trauma and EMDR on the Heartfelt Mind Therapy website. As a trauma-informed therapist who uses trauma-focused approaches, I’d be glad to support you in your healing journey. Reach out today to schedule a free consultation call! 

Warmly,

Sophia Rodriguez

References* 

Original Research: Neural patterns differentiate traumatic from sad autobiographical memories in PTSD (Nature Neuroscience, 2023).

News Source: Neural Patterns Differentiate Traumatic From Sad Autobiographical Memories in PTSD (Yale School of Medicine). sad autobiographical memories in PTSD (Nature Neuroscience, 2023).