4. The Polyvagal Theory in More Detail

Autists have an inability to regulate their visceral state in the presence of others. Basically, the child’s vagal nervous system is not sufficiently developed to regulate in a complex setting.

Dr Stephen Porges

Our bodies have an autonomic nervous system. This system works mostly without our control. We breathe, our hearts pump, we digest food and make blood cells all without much conscious attention. Our bodies take care of us and as long as we put in the right food and water and exercise we are mostly okay. Our bodies work pretty efficiently without our having to think about it; it’s mostly automatic.

There are two parts to our nervous system: the para-sympathetic and the sympathetic-adrenal. When your parasympathetic system is in action you are open and calm. Your digestive system rolls comfortably, your heart rate is down, you have control of your bladder, your breathing is normal, your mouth has saliva, you can swallow easily and your eyes are engaged with the world. The parasympathetic system allows a calm state for good health, nourishment, species reproduction and restoration of cells.

When you are in Fight or Flight, the sympathetic-adrenal system is on duty. In this state your heart rate is accelerated, your breathing is shallow, your saliva dries up and it is hard to swallow; you can lose control over your bowel and bladder; ingestion and digestion are difficult; your eyes dilate; adrenaline is secreted. Now your focus is on your body’s safety.

When you are in Immobilization mode, you are no longer operating from the sympathetic-adrenal, but you have passed the fast action into the still mode regulated by an ancient branch of the vagus that is used by animals like reptiles to defend by appearing to be inanimate. Your body slows, your heart rate slows, your breathing slows, your blood pressure drops, but your digestion, bladder and bowel control, eyes and ears are offline – there is nobody home.

The vagus nerve

The vagus nerve is the communication highway, carrying information and connecting the nervous system to the brain and to all the major organs of the body, especially the gut. The vagus nerve works as a bi-directional conduit, relaying information about how you are feeling up and down the body. It allows the body to communicate with the brain, and it is regulated by the autonomic nervous system, which is in charge of the FFI.

The vagus nerve is part of the parasympathetic nervous system and can influence the sympathetic-adrenal system. It is a powerful regulator of visceral (inner body) feelings and tactile pain thresholds. It regulates the gut and the heart; it can raise or reduce cortisol secretion. It can act to soothe the body, it can mobilize the body into action, or it can shut it down. The vagus nerve will read what you need and respond.

The vagus nerve directly supports the behaviours needed to engage and disengage with the environment.

Dr Stephen Porges

The vagus nerve is our ‘action station’. If it is left on too long, it can lead to ingestive and digestive problems, general discomfort and restlessness, sleep disruption and visceral (internal) pain. If your vagal system is on high alert for such a long time, your body can get to feel quite sore and everything can feel quite out of kilter.

These on-too-long vagal symptoms may describe the many physical difficulties associated with autism. Autists often have digestive problems, restlessness, sleep disruption and visceral pain – we just have never understood why.