The polygraph on your face

Why do we find it so difficult to be kind when we are stressed? Why do we sometimes “freak out” under stress, and collapse at other times? The Polyvagal Theory, proposed and developed by Stephen Porges over the past 20 years, helps us understand how interactions between our brain and the rest of our body drive our social behaviour.

Many of us have learned the classical view of the sympathetic nervous system (fight or flight!) vs. the parasympathetic nervous system (rest and digest...)

Porges shows us it's not that simple. His work focuses on the two branches of the vagus nerve which both lower heart rate, but in different ways. The evolutionarily older dorsal vagal branch (which exists in reptiles) causes a complete shut-down response (e.g. freezing, collapsing) when a threat is perceived as life-threatening. The ventral vagal branch (which evolved more recently, in mammals) lowers heart rate but preserves the ability to interact socially. This newer circuit is the “social engagement system” by which we can respond to stress in cooperation with others. If we do need to fight or flee, releasing this newer vagal brake allows us to take action without over-activating the sympathetic nervous system (which would take a toll on the body).

However, this “social engagement system” can only be turned on when you feel safe in your social context. Obviously, if the people around you are planning to hurt you, it doesn't make sense to reach out to them for help! So your nervous system conducts a constant evaluation of risk in your environment - this is called ”neuroception” by Porges to emphasize its unconscious and non-cognitive nature. Depending on the presence or absence of safety cues in your environment, your physiological state will be different, and therefore your response to stress can vary dramatically.

In this video, Porges speaks about the implications of the polyvagal theory for our understanding of compassion. While the theory is quite complex, he is a clear speaker and there are notes and visuals that make the content easier to understand.

A few key points to think about when someone we care about is struggling to self-regulate:

• Our movements and muscular tension, the look on our faces, and our tone of voice are all evaluated automatically (and often unconsciously) and help determine if we are perceived as safe or threatening. The exact same strategy can be successful or unsuccessful depending on whether someone feels safe or in danger with us at that moment.

• Compassion and prosocial behaviour are incompatible with defensive states (which are triggered by neuroception of danger or threat). What does this person need to feel safe, so she can be kind?

• Everyone is “wearing a physiograph, or polygraph, on their face” – a blank look can indicate feeling unsafe or in pain. We often feel insulted when we are speaking to someone and his face goes blank – he must be ignoring us! How rude! What if we read blank affect instead as an indication that he is feeling scared or lost? How would that shift our response?

• The “heart-brain connection” is bidirectional (goes both ways) – actions that decrease heart rate (e.g. long exhalations) increase a feeling of safety.

• Neuroception evaluates the internal environment too! As a simple example, sudden itching in an extremity would be incompatible with neuroception of safety. What may the person be feeling inside her body that may be affecting her sense of safety?

The polyvagal perspective is a powerful one in re-framing how we view social-emotional difficulties. For those wanting more information, this article on neuroception is a good place to start (probably the easiest read of Porges’ written work).