Polyvagal Theory, Fight, Freeze or Engage

The autonomic nervous system is a control system that regulates bodily functions, over which we have no control such as the heart rate, digestion, respiratory rate, pupillary response etc. The basic objective of this system to keep us safe from dangers.

The autonomic nervous system has two branches: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system is responsible for fight and flight response when a person senses fear or danger, while parasympathetic nervous system consists of vagus nerve.

The vagus nerve has two branches – dorsal and ventral. The dorsal branch is older branch and in case of fear or danger immobilizes a person i.e. faint or act dead. Ventral branch is recent in evolutionary history as is found in mammals. The function of ventral branch is to put brake on fight and flight response and make person feel calm and safe and indulge in social communication.

“There are actually two vagal systems, an old one and a new one- dorsal and ventral. That’s where the name polyvagal comes from.”

-Dr. Stephen Porges

Dr. Stephan Porges came up with Polyvagal Theory to explain how we respond to fear. We follow a hierarchical pattern. We first start with the newest system (ventral vagus system), then move to older system (sympathetic nervous system) and finally to oldest system (dorsal vagus system)

“The hierarchy is composed of three neural circuits. One circuit may override another. We usually react with our newest system, and if that doesn’t work, we try an older one, then the oldest. “

-Dr. Stephen Porges

When we sense fear our first response is calm down and to engage socially (ventral vagus system) ex. cry for help, plead for forgiveness, try to clear misunderstanding etc.

If this mechanism fails then we move to next level which is fight or flight ( sympathetic nervous system), if that mechanism too fails then we  get immobilized by fear ( dorsal vagus system).

“The limbic system “grabs” the sympathetic nervous to turn on defence systems including the fight or flight mobilization system and the freeze immobilize system. But the freeze response is totally different; where fight and flight are mobilization, freeze is immobilization, and immobilization is potentially lethal for mammals.”

-Dr. Stephen Porges

Ideally we should keep our response to first level. We should calm down and try to resolve fear using social engagement. It keeps fight or flight response in control, but if social engagement does not work then it allows fight or flight response to take over ex. at times running away is must for survival.

Getting immobilised may be useful for other animals, but may not be useful for humans, there is very little you can achieve if you are scared to death.  Fight or flight is better response than getting freezed.