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Trauma and the Brain, Vagus Nerve and the Body

Originally posted June 26, 2017.

“We use our minds not to discover facts but to hide them, One of the things the screen hides most effectively is the body, our own body, by which I mean, the ins and outs of it, its interiors. Like a veil thrown over the skin to secure its modesty, the screen partially removes from the mind the inner states of the body, those that constitute the flow of like as it wanders in the journey of each day. ” – Antonio Damascio, The Feeling of What Happens

I went to the 28th Annual Trauma Conference in the beginning of June this year. It’s hosted by The Trauma Center at the Justice Resource Institute and directed by the grand pooh pah of trauma, Bessel A. van der Kolk, M.D. When it comes to trauma, Bessel is the man. Dr. van der Kolk founded The Trauma Center; he’s also a Professor of Psychiatry at Boston University Medical Center.

Trauma Treatment Advances with Brain Imaging

Trauma research and the clinical treatment of trauma has evolved big-time over the past 20 years. Dr. van der Kolk’s latest book, The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma, reflects the evolution of the discoveries of trauma research and the co-mingled change in treatment approach.

Due to the advances of the use of brain imaging in research, it’s now well known how people experience events. We perceive the world multi-sensorially, through our ears, eyes, nose, kinesthetic sense, etc.

Our perceptions are processed by the thalamus to move along the “low route” first, through the lower part of the brain, the emotional brain.

Before we move on, a word about the thalamus. The thalamus is a filtering station, not just a router of sensation. In persons with trauma, the thalamus is less able to filter sensations, and so the background sensations around the person are not relegated to a lower significance than the task at hand. In a person suffering from trauma, street noises, lights, motion outside, etc.. intrude upon his or her daily experiences and it will present as sensory processing issues, when it really might be trauma symptoms.

Back to the lower brain processing….The amygdala, which stores emotional memories, with no associated language, tests out the incoming sensations for emotional significance.At the same time, but just milliseconds later, the thalamus passes the sensations along to the “high road,” to the neocortex, where the experience is interpreted with more discernment and with the opportunity of reflection on experience.

The thing is, if the amygdala perceives a threat to survival on an emotional level, there is a big response. The lower brain has the ability to highjack the body with a strong fight, flight or freeze reaction, invoking anger or fear…punching out, running away or freezing, maybe feeling faint. Only when the experience comes online to the neocortex does the person begin to “come to” in the present moment. A traumatized person can have a hyper-sensitive stress response and a hyper-sensitive startle response, or what’s called an irritable amygdala.

So, the thing is, that in a complex world, with lots of noise and smells and other types of sensory triggers that stir up trauma memories of trauma, this is a rough way to live. Everyday experiences in certain setting, like walking down a street at dusk, or the sound of a helicopter overhead, provides rich sensory input that the thalamus is primed to pass along with a high attentional rating. And when the emotional brain interprets, or perceives, the sensations as a threat to survival, the neocortex is pretty much offline. These reactions have been hard-wired into the brain, are irrational and are pretty much happening outside of conscious control. Insight oriented psychotherapy alone won’t stop the power of flashbacks, as the physical changes of PTSD need to be addressed as well.

Top Down and Bottom Up Trauma Treatment

So, van der Kolk has come up with terms to define how to treat trauma: top down and bottom up. Top down treatments strengthen the ability of the upper brain, the neocortex, to monitor your body’s reactions and then step back and modulate the reactions of the irritable amygdala. Mindfulness and yoga are top down treatments that strengthen the neocortical pathways. Bottom up treatments balance the autonomic nervous system (ANS) through treatments such as breath, dance, singing, rhythm, drumming, movement and touch.

Plus, the way traumatic memories are stored disrupt the neocortex’s ability to keep track of time. So traumatic memories have a timelessness to them; they do not have a narrative with a beginning, a middle and an end, they feel timeless and desperately never ending. To rewire the brain’s stuck feeling of the timelessness of trauma, all trauma treatment needs to take place with grounding, safety and being rooted in the present, while experiencing the past at the same time. This way the brain slowly re-establishes the reality of a narrative and a timeline.

And, trauma treatment is not just desensitization to the original trauma, with the purpose of reducing flashbacks. Trauma treatment is the reconstruction of the brain structures that have actually shrunk from disuse because of the traumatic experience. Dr. van der Kolk says the rebalancing of the emotional and cortical brain areas (balancing the emotional and reasoning responses) by reconstruction, sets the person into the arc of full experiencing of the joy of everyday life, rather than staying stuck in the trauma.

The Vagus Nerve (also Called the Tenth Cranial Nerve)

The basis for using top down and bottom up treatments for trauma is based in part on Steve Porgas’ Polyvagal Theory. Stephen Porges, of the University of Maryland, developed the the Polyvagal Theory. Poylvagal refers to the multiple and complex branches of the vagus nerve (the tenth cranial nerve), which starts in the brain stem, runs throughout the brain, the nervous system, stomach, intestines, heart, and numerous other organs. What’s the tenth cranial nerve? Why is it important? There are twelve cranial nerves housed in the brain. Each cranial nerve is in a pair which runs down the left and right side of the body.

The vagus nerve (the 10th cranial nerve), is the longest of the cranial nerves. It is both a motor nerve and a sensory nerve. It controls muscles and sensory information. It starts in the brainstem just behind the ears. It travels out of the skull, down each side of the neck. It runs throughout the muscles of the throat, the heart, the stomach, the large intestine, the spleen, liver, and kidney. The vagus nerve helps us breathe, talk, swallow, regulates heartbeat, and digest. Its work is done outside of our conscious control. The vagus nerve tightly couples brain and body reactions, as they are in constant bidirectional communication.

Dr. Porges named the ability to detect safety and danger around us “neuroception.” Neuroception is a whole body experience; it is built into our ability to feel the visceral experience inside our bodies and the outer experience of the people around us. The vagus nerve connects us socially to the outside world, through our facial expressions, smiling, talking and pleasant social experiences that feedback to our breath and organs in a relaxed manner. But when danger is threatened, our facial expressions change, and so does the breath, the diaphragm, the heart, the kidneys, the digestion. All of these areas are innervated by the vagus nerve. Fight or flight enacts, but there is also the freeze response. The freeze response occurs when we can’t get away, when we are held down or trapped. This is when the reptilian brain takes over and we shut down and freeze or collapse.

So, due to how the vagus nerve interacts with the muscles and organs of the body, the trauma is encoded in the brain, in the nervous system, in the muscles and in the organ responses. And the vagus nerve pathway, the social and body-based pathway, is an entry way to treat trauma.

The upshot of this is that trauma causes alot to happen physically in the body and there are multiple ways to engage the brain and body in treatment. Dr. van der Kolk maintains that more than insight-oriented talk therapy is needed when dealing with trauma. Top down (yoga and mindfulness) and bottom up (movement, sports, dance, singing, theater, positive social engagement, touch, drumming) therapies are needed to help rewire and reconstruct the brain structures and the body responses. Trauma and recovery are part of the human story, indeed, the bottom up therapies Dr. van der Kolk recommends resemble indigenous culture’s shamanistic healing rituals.


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