Why is it that, when someone experiences post traumatic stress disorder (PTSD), they keep reliving the traumatic incident? The answer is complex, but there is a simple way to understand it using the metaphor of a book in a library.
When we are faced with a threatening situation, our autonomic nervous system (ANS) jumps to our defense, sending out a cascade of neurochemicals designed to ignite life-saving behaviors (see a more comprehensive explanation of this process in the article, “Where are You on the Trauma Map?”
Taking the “Librarian” Offline
At the moment of ANS activation, many things happen at once behind the scenes of our conscious awareness. Among the changes that occur in that split second is the rerouting of our cognitive processing. Because the ANS has sensed danger, it cuts out of the processing loop the prefrontal cortex (PFC), where we do our higher-level thinking and memory processing. This is to prevent us from having an extended debate with ourselves about whether running or fighting the lion is the better option and instead allows our body to react immediately.
The PFC has many important jobs, including assessing signals from the environment (sensory stimuli) to determine whether and how to respond to the world. When the ANS shuts down communication to the PFC, all of our sensory input is experienced “raw.” This has the benefit of allowing lightning reaction, but there’s no “librarian” compiling the pieces and weaving them into a comprehensible story. Memory parts – sensations, thoughts, emotions, and time sense – may all be stored like separate pages, but they aren’t compiled in a single volume and filed neatly on a shelf in the brain.
And because these memory pages aren’t tied together in a single memory book, they have lives of their own. Without being connected to a single story or to a single point in time or even to particular sensations, emotions, and thoughts, they may arise seemingly out of the blue.
To better illustrate this, let’s look at an example. A soldier loses his childhood friend when a roadside bomb explodes during a patrol. This event is highly traumatic because he witnesses it and also was arguing with his friend right before the explosion. When he returns to civilian life, anything that approximates the sound of an explosion – the garbage truck banging cans, a car door slamming, a screen door whacking – causes the soldier to jump and experience a high level of anxiety and fear, as if he were back at the scene in the war zone.
The Problem of Unbound “Pages”
In his higher-level mind (PFC), the soldier knows these sounds are not explosions, but his ANS links the free-floating memory part (the explosion sound) to the banging, slamming, and whacking and activates the trauma response system … as if the soldier WERE still in the war zone and these were life-threatening events. In other words, the sound of the explosion has not been tethered to a story that took place at a particular time. Rather, it lives in its raw state and acts as an early warning beacon all the time. In fact, over time, it may become more generalized until any sharp sound triggers the response.
Novelist Kurt Vonnegut, who lived through the firebombing of Dresden, Germany, during World War II, captured the havoc that PTSD wreaks on time in his classic work, Slaughterhouse-Five. In the story, Billy Pilgrim becomes “unstuck in time” and randomly finds himself in scenes from different episodes in his life. In addition to the often unpleasant and sometimes unbearable symptoms of ANS activation, this temporal dislocation can be completely disorienting and overwhelming for PTSD sufferers.
Those who experience PTSD symptoms resulting from unprocessed trauma memories feel at the mercy of their bodies, which are working overtime in a misguided effort to keep them safe. They may not be able to sleep because when they close their eyes they see (untethered) scenes from the traumatic event; they may feel dread in response to a particular smell; they may panic in elevators or other confined spaces; and so on.
Why a Coherent Memory “Book” = Healing
Trauma treatments, such as EMDR, the Comprehensive Resource Model, and Trauma Dynamics, use step-by-step procedures to integrate traumatic memory parts into a coherent whole. Once the PFC “librarian” has completed this process, the “volume” of that memory will sit on the “brain shelf” to be accessed at will. This means that the intrusive thoughts, sensations, and emotions become tethered to a story that happened in the past and no longer invade present day activities.
Of course this is a gross simplification of the process, but may help to make sense of the sometimes bizarre and always frustrating symptoms that arise as a result of PTSD. Even knowing that these symptoms are typical can be helpful. And finding the right treatment can be truly life-saving.
Alexandria Hayes, MA, LPC, is a therapist and trauma specialist at The Labyrinth Institute. You can contact her at alex @ lab-inst.com or 720-588-3639.