What is the vagus nerve?
This two-way communicator that runs from the brainstem all the way to the colon, is comparable in size to the spinal cord. It truly is the epicentre of the mind-body connection. It changes how we feel, think and act when we move into the different states of the autonomic nervous system depending on our level of stress activation.
The vagus nerve changes how anxious we feel, how fast our heart beats, our digestion, our immune and endocrine (hormonal) systems and it changes how we relate to other people.
How does it impact the rest of our body?
The “social engagement system” is formed by the branch of the vagus nerve that connects the heart to the muscles of the face, the muscles involved with speech and the muscles of our middle ear.
The social engagement system is the reason why our nervous systems are powerfully influenced by other people. It controls how we look, listen and how we speak, depending on our level of stress activation. Another person’s voice, gaze, expression and gestures all influence us, and we influence them, creating a feedback loop.
When our vagus nerve is engaged we’re in a calm, regulated state. If the people around us are also in this state, signals are being sent and received of safety and this resonance leads to connection and co-regulation of each person’s nervous system. Feel good neurotransmitters are released: specifically oxytocin and endorphins. Our physical, emotional and psychological well-being all improve when we’re in our social engagement system and when co-regulation takes place.
So, how is stress contagious?
When someone is in their social engagement system their voice will have high variation in rhythm and pitch and their face will be expressive when they talk to us. This sends signals to our nervous system that connection is safe.
Communication is optimised when we’re in our social engagement because the muscles of the middle ear are primed to detect mid-frequency sounds: the sound of the human voice. We’re also in the state where reciprocity and empathy are high – this means there is the turn-taking with communication and with giving and receiving care. It also means we’re more likely to see another person’s point of view.
Eye contact, welcoming gestures and attuning to another’s experience engage the branch of the vagus nerve called the “vagal brake”. It connects to the heart’s pacemaker (the sinoatrial node) This connection causes our heart rate to slow down, our physiology is regulated and our stress decreases. This means when we’re feeling anxious, just being around another person in their social engagement system can help us move back into ours too.
When we’re around someone who is experiencing high levels of stress activation they have moved outside of their social engagement system into the sympathetic nervous system state and their vagus nerve is inhibited.
The muscles to do with speech change and so their voice becomes monotone. There’s a loss of the expression in their face when they communicate and this can signal to the survival part of our brain that something’s wrong.
Their gestures and body language excite the mirror neurons in the resonance circuits of our brain and signals are sent down into our body that make us feel anxious, reactive or that we need to move away from this person. We lose the feelings of calm and ease because the vagal brake is inhibited, our heart rate increases, and cortisol is released. We move from connection to protection.
When someone is in the sympathetic state of their nervous system the muscles of their middle ear change and they don’t hear the sound of our voice as well. This makes listening difficult in times of conflict and arguments, and it can lead to a lack of reciprocity (the back and forth of communication) and attunement (the felt sense of being truly seen and heard by another).
If the connection in a relationship doesn’t feel secure the sympathetic nervous system can cause responses like interrupting, criticising, blaming, arguing and demanding attention.
It could also bring shutdown responses of stonewalling, silencing, isolating, distancing or withdrawing.
It’s not until we move back into our social engagement system and communication is optimised do we find reciprocity and attunement again. We feel a sense of calm and ease thanks to the engagement of vagus nerve re-regulating our nervous system.
Healthy relationships with high reciprocity help reshape the nervous system: this is like doing bicep curls for your vagus nerve. The back and forth of communication and the giving and receiving of care both build connection and coregulation that shapes your nervous system so you feel a sense safety and belonging when you’re having a difficult time. Both your physical and psychological health can improve (or be impacted) by the people around you.