Polyvagal Theory

Our autonomous nervous system, which regulates vital bodily functions such as breathing and heartbeat via feedback loops, has also developed phylogenetically in stages. Stephen Porges assumes that the vagus nerve (10th cranial nerve) is divided into two parts. In his polyvagal theory (1995/2001) he points out its immense importance within the parasympathetic regulation of our nervous system and thus also of our behaviour.

He distinguishes three separate neural circuits, each of which enables different adaptive behavioral strategies.

The dorsal vagus complex:

Is activated by the perception of life-threatening danger and promotes the conservation of resources through passive avoidance as well as immobilization (fainting, dead point ref ex etc.). The prevalence of the dorsal vagus complex can be seen mainly in less favourable behaviours such as withdrawal, apathy, resignation, demotivation and disinterestedness.

In children, symptoms such as ADHD, defecation/enuresis, few social behaviors, low facial expressions, etc. indicate predominantly dorsal regulation.

The sympathetic nervous system:

Is activated by the perception of danger. It promotes defence and emergency reactions by mobilising resources in the sense of known fighting or escape behaviour. A great deal of energy is required for this. Once the sympathetic system is activated, it is also difficult to switch it off again.

The consequences can then be inappropriate reactions such as fear and aggressiveness, in children ADHD, as well as the preliminary stage of the well-known burn-out syndrome.

The ventral vagus complex According to Porges, this part describes the phylogenetically more recent part of the autonomic nervous system that promotes relaxation and calmness by inhibiting the influence of the sympathetic nervous system on the heart.

Neuroanatomically, it is also connected to the brain nerves that control speech and facial expressions. A so-called "social contact system", which allows the control of the face and head muscles and, through this, also influences our social behaviour.

The problem: The ventral vagus complex only switches on when the person perceives his or her environment as sufficiently safe. But how does our nervous system know when the environment is safe, dangerous or life threatening? In other words: What ultimately activates which part of the autonomic nervous system? The answer: through neuro-reception.