Tuesday, 2 April 2013

Trauma and Brain Body Interactions

Interpersonal Neurobiology Conference

I have returned from my conference in LA, which was truly inspiring. I followed this with a family vacation where I finished reading Robert Scaer’s book – 8 Keys to Brain-Body Balance, which I highly recommend to any of you interested in the Brain-Body interface or developmental neuroscience in general. Robert Scaer has been himself deeply influenced by the work of Peter Levine, who presented at the conference, and whose work I found deeply moving and inspiring.

In this post,  I would like to cover some of the key points that have hit home for me over the course of this conference, focusing on some of the overlaps between presenters and, in particular, some of the key insights from the work of Peter Levine and Robert Scaer. (Scaer unfortunately did not present at the conference).

Here's a great interview with Robert Scaer by Dr. David Van Nuys. click here

Windows of Tolerance



 First, I would like to refer to a concept that was raised repeatedly at the conference. This is the concept of “windows of tolerance”. What this concept refers to is how we develop a range of emotional and physical responses over the course of development. In this process our nervous system and our physiological responses become integrated and we develop a changeable set-point (sort of like a thermostat). This occurs through a very complex interaction of our genetic make-up and our lived experiences. Many of the key points of this development I have referred to in my previous posts (Allan Schore's work). Through these repetitive and rhythmic interactions in the womb and in the first 2-3 years of life, our physiology and nervous system may develop a broad range of flexible arousal which allows us to adapt to many different situations in our environment (i.e. a wide window of tolerance – see figure 1). Alternatively we may find ourselves with a narrow window of tolerance, outside of which we experience disruptive reactivity or paralyzing immobility (see figure 2).

Figure 1

Healthy attachment and attunement, in the context of a stable environment and community, lead to wide and functional windows of tolerance. Alternatively expressed genetic factors and or environmental factors, that interfere with this development, lead to narrow windows of tolerance. A narrow window of tolerance may lead to strategies to avoid extremes, resulting in rigid patterns of behavior, or alternatively, a tendency to experience extremely chaotic emotional states.

Figure 2



Brain Body Interactions

Robert Scaer has proposed a robust theory of body-mind interactions that expands on the physical implications on this brain body balancing act. He explains the implications of being is a state of chronic high arousal. When the thermostat is set too high, into the chronic arousal state at the top of the graph, the body releases cortisol which over a long period of time can result in chronic health problems, such as high blood pressure, obesity, diabetes, stroke, and suppression of the immune system. High cortisol also results in damage to the hippocampus which I have explained in a previous post is responsible for memory and learning, therefore causing memory impairment and learning difficulties. In the extreme, these high arousal states can result in paranoia and psychosis. On the other hand when the thermostat is set too low, low arousal states can lead to problems with chronic fatigue, heart irregularities, irritable bowel, asthma and  overactivity of the immune system.

When Trauma Strikes


A key factor that can lead to narrowing of our windows of tolerance is trauma. A traumatic experience is any experience that at the developmental stage of the individual (which varies accross development and with experience) pushes them completely out of their window of tolerance, with no expectation of safety. Scaer goes on to explain that when we have a traumatic experience we may enter a freeze state. The key brain area that assesses our environment and engages the freezing response is the amygdala. The amygdala is active from the third trimester of a fetus' development, and therefore, Scaer points out, we are susceptible to trauma even prior to being born. Traumatic memories are not encoded in the part of our brain that encodes ordinary memories. Those ordinary (explicit) memories are encoded by the hippocampus, which does not come online until the second to third year of life. In trauma, the hippocampus is disabled, as are the parts of our brain that control language.  When this occurs the motor movements and sensations that we are engaged in just prior to this are stored in a form of memory called procedural memory. If this state of action and sensation is not “discharged”, which requires entering a state of calmness where we can return to emotional state prior to the trauma, these motor and sensory memories remain active and the traumatic state is stored in a sort of "perpetual present". (Scaer himself had a facial tic which was a remnant of traumatic incident he experienced at the age of 4.) Motor memories can lead to chronic changes in posture, tics or stutters. Sensory memories can lead to chronic pain conditions, an example of which is the phantom limb phenomenon.

Peter Levine has developed a therapy which he has named Somatic Experiencing which engages the client in gradually accessing the stored motor and sensory memories of trauma, while deactivating the amygdala by careful attunement and providing resources to the patient that establish safety and empowerment.


In summary, the brain and body exist in a complex relationship with one another. Various life experiences can contribute to healthy and flexible brain-body interactions and others can lead to rigid or chaotic brain-body states. With a deeper understanding and appreciation of these patterns, we in the healing professions may be capable of profound healing. Without this understanding, we run the risk of perpetuating or even worsening these imbalances. In general, our health care system remains ignorant of these interconnections and we continue to treat the brain and body as strangely disconnected. Hopefully as the neuroscience and physiology of these interconnections becomes better understood, we will become better at improving the brain body balance in ourselves and in those we care for.

1 comment:

  1. Thanks for helpful explanation on this. I am reading up on this seemingly new body therapy for trauma. Try listening to the episode of Shrink Wrap when Dr Dave interviews two Californian Child Protection Service therapists who are treating parents of at-risk children with somatic experiencing therapy, which seems similar also so Pat Ogden's Sensorimotor psychotherapy.