Published: Apr 4, 2019 by Chloe
Some people's lives seem to flow in a narrative; mine had many stops and starts. That's what trauma does. It interrupts the plot.
-Jessica Stern, 'Denial: A Memoir of Terror'
Bessel van der Kolk’s ‘The Body Keeps the Score’ is a classic text on the experience of and recovery from trauma. Here I want to summarize and discuss some notes from the book specifically on the nature of traumatic memory: how it compares to “ordinary” memory, how we integrate memories into the narrative of our lives, and the fixation vs. malleability of memory.
The functions and nature of memory
Memory serves obvious survival functions, such as remembering where to find food or shelter and remembering places and people of safety or harm. Memory also serves a social purpose, Dr. van der Kolk writes. He doesn’t expand upon this point, but I interpret that to mean we use memories as the building blocks for a narrative we tell ourselves and others about who we are, what we have experienced, and the interaction between our sense of self and what we have taken away from those experiences. This narrative is what we use to navigate the world and our interactions with others. It is also the thread that allows us to connect our past “selves” with our present identity in order to create cohesiveness across time and experience.
A memory is encoded in the moment with the emotional features (salience and valence) and sensory associations that were present at the time of the experience. However, when memories are later recollected, they are rendered labile again: they can be re-encoded within the emotional and sensory context of the present in which they are recalled. This is one mechanism by which memories tend to lose emotional salience over time. An experience that was deeply troubling, embarrassing, or triumphant at the time will retain wisps of those emotions but the salience typically fades. If you recall an embarrassing memory at a later date, the present situation in which you remember it is likely not evocative of embarrassment like the original memory was, and the memory gradually loses that power. It is a neurological explanation for “this too shall pass.”
How traumatic memory differs
Traumatic memory is distinct in those two ways: it does not fit within a cohesive narrative about ourselves and our lives, nor is it as easily malleable. People often struggle to make sense of traumatic memories and describe them and the associated feelings using metaphors of tangled webs or knotted strings (Dr. Jamie Marich, Trauma Made Simple). Traumatic memory is also resistant to updating. Instead of being rendered labile by recollection, traumatic memories can induce a state of capture. In a captured state, the brain is stuck with the emotional and sensory associations of the memory often in a way that interferes with behavior and quality of life, such as a flashback.
Dr. van der Kolk writes that traumatized individuals simultaneously remember too much and too little. The “too much” part comes from the intensity of images, sounds, smells, or other sensory connections to the traumatic memory that induce that state of capture. The “too little” part comes from the somewhat paradoxical fact that it is often extremely difficult to remember the precise details or sequence of events of traumatic memory, and traumatic memories can even go entirely repressed for years until triggered by something, often by stress.
There is much still to be understood, but neuroscience has been able to shed some light on why the nature of traumatic memory is so distinct, which I’m not delving extensively into in this post but I want to highlight some of what Dr. van der Kolk discusses.
Memory inside the brain
Dr. van der Kolk writes that the left-brain vs. right-brain dichotomy is not entirely pseudoscience. There are documented differences in the way the two hemispheres of the brain experience the world. The right hemisphere processes information in a more experiential, emotional, and sensory way. The left hemisphere does so more linguistically, analytically, and sequentially, weaving a narrative thread between feelings and experiences that connects them in a logical and temporal way. According to MRI studies, traumatic memories engage the right half of the brain over the left. The way the right half processes information reflects the nature of traumatic memory: the memories come in bits and pieces of sensory stimuli, rather than a cohesive, narrative whole. They are difficult to put into words. The distinction between past and present becomes blurred, and often, but not always, intense emotions are evoked.
It is also difficult for the prefrontal cortex to engage with traumatic memories. The prefrontal cortex is responsible for much of the “top-down” control that we as humans are able to exert over emotional responses, largely by modulating activity in limbic brain regions such as the amygdala, which shows hyperreactivity in cases of stress and trauma. The prefrontal cortex allows for cognitive reappraisal of information and of experiences. In other words, it allows us to control what we think about something. The mechanisms of how the prefrontal cortex is rendered deficient in instances of trauma is still being studied, but there is evidence to suggest that some treatments for trauma, like EMDR, help to reengage the prefrontal cortex.
Dissociation
Dissociation is a common part of traumatic experiences. Dissociation is a disconnectedness from the memories. It can involve what some have described as a “floaty” feeling, as if one is detached from what happened and viewing it from above or from a distance, or not engaging with it at all.
In what I’ve read about trauma, dissociation is often talked about as something to be avoided or overcome. But I am not convinced it is inherently a bad response. First, of course, it can be protective, preventing someone from being thrown back into a traumatic experience. Second, many meditative practices involve achieving a dissociative-like state in which one is able detach oneself from the daily struggles and highs and lows of life and be less at their mercy. In this detached state, one may be able to find a peace that comes from acceptance of the transience of feeling and memory.
My personal take on a dissociation is that it is a step in a process. It may allow us to take a step back from our memories and realize that the meaning, the emotional valence and salience that is attached to them, does not need to be permanent. Trauma, almost by definition, carries with it high salience and negative valence. Dissociation may be a step in detaching those emotional associations from a traumatic memory. But something, at least for me, needs to come next. Dr. van der Kolk’s words describe what I find to be the problem with dissociation by itself:
Dissociation prevents the trauma from becoming integrated within the conglomerated, ever-shifting stores of autobiographical memory, in essence creating a dual memory system. Normal memory integrates the elements of each experience into the continuous flow of self-experience by a complex process of association … but in [trauma’s] case, the sensations, thoughts, and emotions of the trauma were stored separately as frozen, barely comprehensible fragments. If the problem with PTSD is dissociation, the goal of treatment would be association: integrating the cut-off elements of the trauma into the ongoing narrative of life.
What is the therapeutic purpose of integrating traumatic memories into the narrative of our lives? It allows the emotional and sensory associations attached to traumatic memories to be updated according to the present context, as happens with normal memory. As Dr. van der Kolk puts it, “as long as a memory is inaccessible, the mind is unable to change it.” Associating and engaging with traumatic memories also enables people to make sense of those experiences, to decide what meaning they want to assign to them and what role they want them to have in their lives. In other words, it allows people to take control of the memories. The meaning that one attaches to their traumatic memories can be anything from peaceful acceptance of what happened to inspired empowerment; whatever the meaning, the goal is that the memories are able to take on new emotional associations that are beneficial to the individual and no longer interfering with quality of life.
