How Traumatic Memories Change: A Memory Reconsolidation Perspective
Much of my clinical work is guided by the principle of memory reconsolidation.
A helpful way to understand trauma is to consider how the brain stores experiences. When something highly salient happens—particularly something relevant to survival, such as a traumatic event—the neural firing pattern associated with that experience can become consolidated into long-term memory. Most experiences do not undergo this process, but events charged with intense threat, helplessness, or overwhelm often do.
Once consolidated, the memory is no longer in an “editable” state. It is stored in a compressed form—much like a zipped file on a computer. From that point on, this memory functions less as a story about the past and more as a set of implicit emotional learnings about the world, other people, and oneself. These learnings shape reactions automatically, often without conscious choice.
For someone with PTSD, this can show up in very concrete ways.
A sudden sound, a facial expression, a tone of voice, or a bodily sensation can instantly bring back a rush of fear, shame, or helplessness—as though the original event were happening again. Even when part of the person knows they are safe, the body reacts first. The heart races, muscles tense, breathing changes. This is re-experiencing: the traumatic memory network has been activated, and the nervous system responds based on what it learned then, not on what is true now.
Over time, the system learns to prevent this activation whenever possible. Someone may avoid certain places, conversations, emotions, or even internal states. They might stay busy, emotionally numb, or disconnected from their body because slowing down feels dangerous. This is avoidance—not a lack of motivation or insight, but a protective strategy aimed at keeping overwhelming material out of awareness.
At the same time, the nervous system often remains on high alert. Sleep is light or fragmented. The body startles easily. There may be a constant sense of bracing, scanning, or waiting for something to go wrong. Irritability, hypervigilance, and difficulty relaxing are common. This is hyperarousal: the implicit belief that danger could appear at any moment, and that vigilance is necessary for survival.
Underneath these symptoms are emotional learnings that were adaptive at the time of the trauma. Learnings such as:
The world is not safe.
I am powerless.
I have to stay alert to survive.
If I feel too much, something bad will happen.
I am alone with this.
These are not thoughts someone chooses to believe. They are embodied predictions encoded in long-term memory. They organize emotions, shape behaviour, and influence relationships automatically, long after the original danger has passed.
For many years, trauma treatment focused on helping people manage these reactions—learning to calm the nervous system, avoid triggers, or function despite them. While these skills can be helpful, research over the past few decades has shown that deeper change is possible.
When a traumatic memory is reactivated—when someone feels triggered—it briefly returns to a malleable, editable state. In this window, the memory effectively “unzips.” While it remains open, it can be revised.
For that revision to occur, the nervous system needs to experience something emotionally meaningful that contradicts the original learning. In trauma therapy, this often involves a lived sense of safety, agency, and compassionate connection—especially in moments when the old memory is present.
For example, someone might notice fear or collapse arising while staying grounded in the present, supported by another person, and discovering that the feeling can be tolerated without being overwhelmed. Or they might sense a compassionate response toward a younger, wounded part of themselves—offering protection, understanding, or care that was missing at the time of the trauma. The specific form varies, but the essential ingredient is the nervous system registering: something different is happening now.
When this mismatch is strong and sustained, the brain updates the original emotional learning before reconsolidating it back into long-term memory. The same memory may still exist, but it no longer carries the same charge or meaning. Triggers lose their intensity. Avoidance becomes less necessary. The body no longer needs to stay on constant alert.
Experiential psychotherapies that emphasize relational safety and somatic awareness are often particularly well suited to creating these conditions. By helping people feel safe both in the therapeutic relationship and in their own bodies, these approaches allow traumatic material to come into awareness while the nervous system remains regulated enough for new learning to occur. Over time, this combination of presence, attunement, and embodied safety can support the reconsolidation process at its core.
In some cases, additional tools can further support this work. Psychedelic-assisted therapies, such as MDMA-assisted psychotherapy, can deepen access to emotional openness, compassion, and connection, while temporarily reducing fear-based defenses. When used carefully and within a strong therapeutic framework, these medicines can help facilitate the same fundamental process: updating the emotional learnings stored in long-term memory so that the present no longer feels organized by the past.
Taken together, this way of working views PTSD not as a disorder to be managed, but as a coherent nervous system organized around past learning. Symptoms make sense when understood in light of what the mind and body had to learn to survive. Healing, from this perspective, emerges when those learnings are gently brought into the present and met with experiences of safety, agency, and compassionate connection that were missing at the time. Whether through relational, somatic psychotherapy alone or with the careful support of additional tools, the aim is the same: to allow the nervous system to update its predictions, so that life can be lived with greater flexibility, presence, and choice.
