As previously stated, the reptilian brain controls our physical response to threat-flight, fight or freeze (these are all reflexes) . I’ve written often about tracking the sensations in the body; the language of the reptilian brain is sensation. Balance, initiation of movement, breathing, digestion, circulation, sleep, sexuality and action are all governed by this oldest part of the brain.
The reptilian brain-or brainstem-also effects the energy levels of the brain area above it; the limbic and cortex. It controls arousal, appetite, sexual engagement and sleep. When there is trauma in the body, the reptilian brain stays on ‘on’ and all these systems are impacted.
I recently completed my fifth module of a nine module (3 year) training in Somatic Experiencing. I am still in awe, still so grateful I found Peter Levine’s tremendous work. I want to share some of the most striking things I have learned; if you are unfamiliar with Dr. Levine’s work, you might read “Waking The Tiger”.
I particularly love learning about the reptilian brain, also known as the brain stem. I think of a reptile slowly dragging itself around, always on the look out for danger, constantly scanning the environment. We, as modern 21st century people, don’t think too much of this part of our selves, being more identified with the thinking, rational cortex. But it’s there and it still scans and when it senses danger it signals the automatic nervous system.
In previous blogs I wrote about Peter Levine’s model being based on the way animals shake off trauma; if the prey survives the predator, it literally shakes the experience out of its body; the reptilian brain is satisfied all is safe, and then the trauma free animal continues along its way. I’ve seen a number of videos of this phenomena; it’s quite striking. The animal is not left with trauma in its nervous system; humans often are. Remember: what makes an event a trauma is if it’s been locked in the nervous system with no apparent way out. The reptilian brain is thwarted and the autonomic nervous system is is deeply affected.
This effect can show itself in many ways and can effect the sympathetic and/or the parasympathetic systems (please see previous posts). Next time I’ll write more about this-
As I mentioned in an earlier post, the brain is divided into two hemispheres-right and left. Although there are two amygdalae, two hippocampi and two temporal lobes, the way they process information is quite different.
The left hemisphere likes things to make sense; two plus two never equals three. Language, logic, and linearity are its hallmarks. It explains the input from the right hemisphere and puts it into neat packages.
The right side is nonlinear, receptive to everything that comes its way. It perceives and processes spatial and visual information such as nonverbal signals. Our mental model of the self and the way we relate to the world is formed on this side; the way we feel ourselves, our story, our relationship to our body and the way we relate to others.
Fight, flight and freeze (please see earlier post) is experienced on the right side. When the two sides are integrated, the right hemisphere provides the felt context for the left side to make sense of; the information flows.
I’m going to go back before I go ahead. Let’s look at the most important parts of the last few posts and how it all relates to Somatic Experiencing and mindfulness.
I love having a feeling for the flow between the body, nervous system and brain. I love understanding how change on one level can effect so many other systems. It’s this flow that is often obstructed by, for example, fear and anxiety. This is true for all of us; musicians, artists, singers and lay people.
The fear antenna is in the amygdala; depending on our history of trauma it may always on alert or, for a system that has no trauma, only activated when it senses possible danger. Somatic Experiencing (SE) teaches us that trauma is what has been locked in the nervous system, unable to escape. Even though we may be not consciously aware of this dynamic, it impacts every part of our life until resolved. It is in this body that the amygdala is vigilant.
Tuning into the sensations of the body is the start of breaking the fear cycle; please read past posts on this.
The hypothalamus, along with the pituitary, is in charge of the neuroendocrine system that releases neurotransmitters. These neurotransmitters increase (excite) or decrease ( inhibit) electrical activity in neurons. Increases or decreases in neurotransmitters have a major impact on mood and behavior.
The hypothalamus produces the the hormones that effect the pituitary gland. Once the amygdala senses danger the sympathetic branch of the autonomic system is alerted and the hypothalamus, through the pituitary, releases hormones that travel to the adrenal glands. This is where cortisol is released (please see posts on the autonomic nervous system and cortisol.) Cortisol increases the level of glucose in the blood to respond to the threat.
Under normal circumstances the threat passes and the cortisol levels return to normal. However many people who have ongoing anxiety live with ongoing increased cortisol levels. This is one of the places Somatic Experiencing is so helpful; it helps people to regulate their autonomic nervous system, decreasing the spiked activity in the sympathetic branch. I have helped many performers-and many others as well-to self regulate; it makes a huge difference in their daily and artistic lives.
The hippocampus is another important structure of the limbic system. Its main function is in the process of remembering; it puts together little pieces of information and forms them into explicit memories. It also retrieves past encoded information. Implicit memory, which takes place in the amygdala, is the form of memory we have until the 12-18 months. It is an evaluation of whether a situation or person is safe-there is no awareness of time.
When explicit memory comes online, the parts of implicit memory are integrated and recognized as coming from the past. Factual memory comes first; the ability to recall events in sequence and locate them in space. Following this autobiographical memory begins.