Polyvagal theory
Polyvagal Theory, created by Dr Stephen Porges, is the science of how our sense of safety, trauma and the autonomic nervous system impacts fear responses, emotional regulation and social connection.
There is a part of the central nervous system called the autonomic nervous system which controls our involuntary processes like heart rate, respiration, blood pressure, digestion and our fight, flight & freeze responses. This system is broken down into two parts the sympathetic nervous system and the parasympathetic nervous system (vagus nerve). The vagus nerve is a key part of the parasympathetic nervous system that carries signals between the brain, heart and digestive system. These systems are always engaged however one is always more active than the other.
Within these two systems there are three main evolutionary survival states which become active depending on whether the brain is perceiving danger or safety.
The three states
- Safety and social engagement (Ventral Vagal Complex – parasympathetic)
- Fight or flight (sympathetic nervous system)
- Freeze - Shutdown (Dorsal vagal complex – parasympathetic and sympathetic)
The theory states that when the autonomic nervous system adjusts from one state to the other, the thoughts and feelings will follow and reflect the state you are in. For example, if you are in a state of fight and flight you will feel anxious or angry and have worrying or irritable thoughts. If you are in freeze and shutdown your thoughts will be more apathetic, you might feel numb and lack energy and motivation. If you are in safety and social engagement you will feel safe and your thoughts will be calmer or more playful.
The fight, flight and freeze response are automatic survival actions which increase our chances of survival when we are faced with danger. They are automatic responses which become active when our brain perceives a threat (neuroception), it is not something you have conscious control over. Neuroception is the unconscious detection of danger or safety in the external or internal environment causing shifts between the different states. They are involuntary responses like an instantaneous reflex. Unfortunately, the brain cannot tell the difference between a real threat to our survival and a false threat, it reacts in the same way physiologically. For example, if a tiger were to come into the room you’re currently in, your neuroception would perceive the tiger as a threat and activate your fight and flight response, but it may also become active if you were to speak publicly or if you feel overwhelmed. The second two scenarios are not a real threat or danger, but your brain cannot tell the difference and reacts in the same way mobilising your flight and flight response.
Fight and flight (sympathetic nervous system)
The sympathetic nervous system is the fight and flight response. When active, the stress hormones cortisol and adrenaline are released giving a boost in energy, heart rate and breath rate increases to provide more oxygen and blood to the muscles for movement. The muscles tense and pupils dilate to see better, all preparing us to fight or flight. This state is active when danger is perceived in either the internal or external environment, it is a biological response that increasing our chances of survival when we face a danger or threat. However, if it becomes out of balance and we are in sympathetic activation predominately in our day-to-day life it can cause havoc on our mental and physical health. If this system is chronically activated, we might feel hyper aware and on high alert for any potential dangers, have a sensitive startle reflex, anticipate worse case scenarios, excessively worry, have anxiety, panic attacks or high levels of anger and irritability.
Freeze response and shutdown (dorsal vagal complex)
Less commonly known than the fight and flight response is the freeze and shutdown response. The freeze response is a mixed state of the dorsal vagal and sympathetic nervous system activation and the shutdown response is dorsal vaga activation. These states become active when the brain perceives that you cannot fight the threat, nor can you get away (flight), it will then activate the freeze response or shutdown. In the shutdown state the blood pressure and heart rate lower and in extreme cases it can cause you to collapse to appear dead. This response increases the chances of survival as some predators may lose interest, like how a mouse that gets caught by a cat plays dead and then the cat loses interest. An example of the freeze response is a deer that freezes caught in headlights. This state creates an altered reality where time slows down and pain is reduced. People who have been mauled by animals and survived report going into an altered state where they felt no pain or fear. If this system is chronically activated, we might feel sadness, numb or dissociated from our body and lack energy and motivation.
Safety and social engagement (ventral vagal complex)
When the parasympathetic nervous system and ventral vagal complex is active the heart rate slows down, blood pressure lowers and digestion functions optimally. In this state we feel joyful, safe and calm, enabling us to socially connect with others, play and experience growth and restoration. This state is active when the internal and external environment are perceived as safe.
Living predominately in fight and flight or freeze shutdown responses
Living in a state of chronic activation of the automatic nervous system impacts the different systems in the body causing an array of emotional, mental symptoms and physical problems such as weakened immune system, muscle tension and pain as well as concentration problems, sleep disturbances, autoimmune problems, cardiac and respiratory illnesses, digestive issues and other health problems.
How yoga helps
You cannot choose your state as it is an unconscious and automatic process, but you can practice working with the body to strengthen pathways towards regulation. In yoga, through movement, posture, breathwork and meditation we are develop more regulation in our nervous system. Though yoga we increase our interoception, our ability to notice and accurately sense our bodily sensations, we build our mind-body connection and use body posture to send signals up to the brain of safety and connection increasing ventral vagal tone bringing more balance to our autonomic nervous system functioning. The more we repeat, the more we are reconditioning our brain and nervous system to automatically and naturally shift into more regulation. With long term practice we might start to see changes in our physical and mental health. We might start to notice we are no longer experiencing fear like we used to, or we might feel less shutdown and numb and have increased energy levels.
To conclude, yoga helps us regulate our nervous system and find more balance and health in our mind and body, which can have a life changing effect on the quality of our life. It aids in retraining our nervous system in a way that cannot be reached by taking purely a cognitive approach. There are also many other benefits of practising yoga, click here to read my blog post on "11 Transformational Benefits of Practising Yoga".
References
The polyvagal Theory – Stephen Porges
The body remembers – The psychophysiology of trauma and trauma treatment, Babette Rothschild
The Illuminated Breath – Dyan Werner
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