Polyvagal theory explained
For all these reasons I wanted to understand what was happening within and between us, because it felt so right, so timeless, so deeply in the body, and so healing. Then I happened upon the polyvagal theory and how it puts together the jigsaw of evolution and the autonomic nervous system’s role in emotion, communication and human relations.
In the traditional view, the autonomic nervous system has parasympathetic ‘brakes’ (rest, digest) and a sympathetic accelerator pedal (fight and flight), which
work together to maintain physical safety. Polyvagal theory proposes however, that the autonomic nervous system is organised into three functional parts and that the vagus nerve is crucially involved not just in the physiology of safety, but also with emotion, communication, connection and trust. The threefold vagus concept helps us understand and predict how humans relate and respond to varying degrees of safety or danger.
Consequently, polyvagal theory has attracted huge interest from in the therapy world. In particular, those of us who work with the impact of trauma having witnessed dramatic ‘freeze’ and ‘fold’ responses, will have wondered what is going on physiologically. Such obviously physical reactions couldn’t be due to sympathetic nervous system ‘flight and fight’, yet nor did they look like resting and digesting. New insights and approaches to therapeutic practice are emerging as a result of Porges’ ideas.
The vagus nerve
The vagus originates in two distinct areas of the brain stem and wanders widely through the body in two main branches, one of which primarily regulates organs above the diaphragm and the other those below. So it connects the heart and the viscera (the organs of the belly) to the brain and, as we were taught, the parasympathetic and sympathetic nervous systems work in reciprocal opposition, with the sympathetic nervous system acting to energise us for physical action by increasing our heart rate and blood pressure, while simultaneously putting other functions like the digestive system on hold. This enables us to run from a dangerous animal or to act quickly to deal with an emergency – for example when we instinctively jump out of the way of an oncoming car without having to stop and think about it. Then, once the need for such extreme reaction to a stressor has passed, the parasympathetic nervous system acts to slow the system down and get our physiology back to baseline.
What Porges realised is that in addition, the vagal system regulates our ability to connect and communicate with each other. Polyvagal theory also explains how in some circumstances both branches of the autonomic nervous system can be active at the same time, for instance in freeze, but also during sex, and when nurturing. In this more complex understanding the autonomic nervous system has a third level of function, which includes a formerly unsuspected role in interpersonal communication and the regulation of the sympathetic nervous system.
According to polyvagal theory the autonomic nervous system operates on three organising principles: neuroception, hierarchy and co-regulation. Neuroception is the term Porges coined for describing our ability for perception below awareness. We constantly monitor our inner and outer environment, especially our internal sensations, how other people are behaving, continually assessing the level of safety or danger; all mainly without having to call on our conscious, thinking brain. Our autonomic nervous system responds accordingly, making moment to moment adjustments, always strongly influenced (often unconsciously) by past experiences of threat, and without the time-consuming, slow and therefore potentially lethal need to think.
If the environment is felt to be safe, the ventral vagal social engagement system makes us relatively free to be ourselves, express our feelings, use facial expression easily, and use a modulated voice pattern. Also, our heart rate is relatively calm, we breathe freely, and we filter out human language from background noise. Whereas if we are not ‘neurocepting’ that the environment is safe, we fall towards a fight or flight, survival mode (as the vagal brakes ease off and the sympathetic nervous system starts taking over. And if that sympathetic nervous system ‘unsafe activation’ system fails too, and we feel dangerously overwhelmed, trapped and unsafe, we may fall back into the freezing or shutting down reptilian dorsal vagal mode. In both of these more primitive modes, most of the human higher cognitive capacities are turned off, leaving a person less able to relate to the world socially and to make good decisions. This cascade of events has important implications for our understanding of burnout and post traumatic stress.
The autonomic nervous system operates hierarchically: its activation follows a natural order in three stages depending on neuroception of a situation’s safety or danger. Porges relates this to the evolution of the autonomic nervous system, where at each stage a different adaptive behavioural strategy – supported by a distinct autonomic nervous system circuit – emerged. When danger – real or imagined – threatens, the autonomic nervous system shifts initially towards the most evolved strategy. If that fails then the more primitive options are triggered: so social engagement/negotiation first; then fight/flight; then fold and fade out when all else fails.
The oldest (from an evolutionary perspective) of the autonomic nervous system’s three subdivisions, is the dorsal vagus. It enables us to shut down, or ‘freeze’ when a situation feels overwhelming or perilously uncontrollable. It’s a defence that reptiles with their small brains and relatively limited oxygen tend to rely on – the main strategy for a tortoise. However, it also shows up in mammals, for example a mouse caught by a cat will ‘play
dead’, or a gazelle taken down by the lion will go limp.
That same gazelle, having feigned death, might, if the lion gets bored and distracted, take the opportunity to escape. This adaptive possibility for instant activation of fight/flight only became biologically possible once the sympathetic nervous system, with its capacity to activate and mobilise escape, had evolved. Fight/flight can be instantaneous in an emergency the moment the inhibitory braking effect of the unmyelinated ventral vagus is removed.
The most evolved and complex of the three sub – divisions is the ventral vagus. This complex network of fast, myelinated neural fibres originates in a different part of the brain stem from the dorsal vagus. Porges explains how in the course of evolution the vagal pathways regulating the heart in reptiles shifted from the dorsal nucleus of the vagus to a more ventral nucleus in mammals. This created a face/heart connection, and a two-way traffic whereby social engagement can regulate the bodily state and vice versa our heart rate and breathing influence our capacity for social engagement. The ventral vagal nuclei in the brain stem interact with nuclei in the brain stem that regulate the muscles of the facial expression.
When reptiles evolved into mammals, a piece of the jawbone evolved to become the part of the middle ear that lets mammals hear not just the low sounds of predators, but those sounds we need to communicate and share information for survival through co-operation. The Chinese symbol for listening apparently contains the symbols for to see, to be present, to focus, to feel, to think, to hear, which is not the same as listening. Activating the ventral vagus changes how we hear, use facial muscles and vocalise via the muscles around the eyes and mouth, and the muscles of the middle ear that work in ways that ensure we look friendly, hear voices better and speak more engagingly. Instinctual stress responses – flight/fight or freeze and fold – reduce access to the human brain, depressing the cortical functions that allow clear thinking and reasoned decisions. But in addition, by impeding the ventral vagus and interfering with the organs of social engagement, being stressed also makes us less friendly as our face, muscle tone and voice change.
However, this ventral vagal network is bi-directional, with most of the traffic travelling to the brain stem from the body rather than vice versa. That’s why, by engaging consciously with our breathing, hearing, facial muscles and voice, we can re-couple the social engagement system. In doing so, as we restore our capacity for communication we can engage with the positive mobilising energy of the sympathetic nervous system, and be enthusiastic, excited and curious. The threefold vagus by balancing activation and immobility in this way makes play and physical intimacy possible and allows us to be close and physically activated with others without this closeness feeling like a threat.
Polyvagal theory suggests that through the complexity of our expressivity, humans have evolved the capacity to co-regulate one another. In fact Porges goes so far as to suggest ‘it is the purpose of human beings to coregulate other human beings’. Clinician and author Deb Dana who uses polyvagal theory to understand and resolve the impact of trauma in our live says, ‘we come into this world wired to connect’ (Dana, 2015). Polyvagal theory is giving us a scientific understanding of how the autonomic nervous system moderates our innate drive to survive with our innate longing to connect with others. We all have more capacity to engage socially when we feel safe, and contrastingly we fall into fight, flee, or freeze when our nervous system is sensing or even imagining danger.
Through neuroception we are constantly picking up signals of safety or threat through facial expressions, eye contact, tone of voice, gesture, tone of voice. The autonomic nervous system adjusts our physical and mental state to meet the situation. But these neuroceptions can be tricky: we have experienced the discomfort and sometimes irritation that arises in conversation with someone who doesn’t look at us. It is breaking the innate rules of safety and connection. Porges calls this ‘biological rudeness’. We are instinctively unlikely to trust this person or situation. To add a complication, we see the world through how we feel, so that the world and people feel more threatening when we are stressed.
Fortunately we can affect our autonomic nervous system with every breath. Our in-breath stimulates the sympathetic nervous system preparing us for action, our out breath stimulates the parasympathetic nervous system, calming us down. So a slow controlled exhale, which activates the organs of social engagement via the ventral vagal complex, changes the heart’s rhythm, makes the voice more ‘musical’, the eyes ‘light up’ and a smile look more genuine. We respond very differently to a voice which has variety in tone to one which is monotone. The lyrical quality of a mother’s lullaby to her baby embodies this. We learn from day one to detect signs of safety and connection from the voice just as we all recognise how one raised in anger or fear makes us feel.
So, to singing…
In terms of our ventral vagal system, singing together ticks just about every box. When we sing, we are generally controlling our breath and extending our exhale and therefore increasing the effectiveness of the myelinated heart-brain pathway and contributing to a calmer physiological state. This two-way feedback loop between brain and heart puts us in a more open state for social engagement. Stephen Porges says, ‘If you sing with a group, then you’re social referencing – you’re engaging with others. So singing, especially singing in a group, is an amazing neural exercise of the social engagement system.’ Singing together changes the pharyngeal and laryngeal muscles, and listening attentively activates the muscles of the middle ear, the muscles of our mouth and face, in ways that link via cranial nerves and the ventral vagus to the heart. Plus, I believe that the quality of embodied, multi-sensory, shared and emergent beauty we create in the choir, through our relationships, co-operation and trust, can be truly healing for people whose relationships have not been safe. When singing together in a circle we are all visible to each other and there is no one behind us: we feel safer, we can read the authenticity on each other’s faces. These are crucial factors for someone whose stressed nervous system makes them feel unsafe.
Setting the scene
When we sing with Helen, she invites us into a safe, inclusive, comfortably contained place, safe enough to overcome the impulse to run for the door, because we are given permission to just have a go.
Helen says: ‘Most people who have breakthroughs when singing for the first time may be overcoming fear from childhood, having been silenced and told they couldn’t sing. A skilled practitioner will be able to tell very quickly, in the first few seconds, who in the group is anxious and scared, and will ease them into the process though body language and eye contact, being gentle and encouraging, smiling a lot and giving a big thumbs up the moment they open their mouths. We can then have the realisation that we are part of something bigger than ourselves, more than the sum of our parts. We feel connected, included and expanded….just singing in unison is a powerful experience but when singing in harmony something magical happens when the third harmony comes in.
‘The first harmony feels quite nice, the second harmony is a bit confusing, so people wonder how this will this fit. Then in comes the third harmony, and with the juxtaposition of the intervals and their vibration, people look at each other in amazement. That’s the magic people respond to – the moment when their parts
suddenly relate and make sense. There’s such joy and wonder, a kind of a shock that in co-creating this sound “my voice is actually contributing to this alchemy!” The best magic is seeing the faces of those who have never before sung in harmony, as they experience it. Those who have sung together before are waiting for that moment. The breakthrough takes place because we are working so directly with the breath and the naked voice, not making sound through a third party or external instrument. This makes it so emotive and emotional – connecting with our soul or spirit – so human. There is so much science on so many fronts that now appears to back up what mystics, parents, teachers, stories, nursery rhymes, games in all cultures and traditions have been passing on or that have
been instinctively felt for ever.
‘The first time I sang as an adult in a community choir was in my late 30s on the recommendation of a friend. I didn’t see myself as a great singer/soloist – still don’t – I just wanted to sing in a group. I was really nervous the first time – I didn’t know anyone, just started singing this song – could read music so could straight away join in. After a few bars I just stopped and listened, feeling in a state of complete and utter ecstasy, I wanted to cry – I couldn’t believe I’d just discovered choir singing in my 30s.
‘I was a single mum with two kids under two – I had a battery of baby-sitters who would take over so I could get to this choir, I even pretended it started half an hour earlier so that I could just drive there and stare at the door waiting for the choir leader to turn up. I couldn’t believe everyone wasn’t doing this. The state of ecstasy and bliss of that first time – I conceived my third child that night!
‘Occasionally I find people who aren’t moved by it, but most are captivated like I was and go home and find a choir. It’s the whole possibility of belonging.’
Helen tells me she’s only had two bouts of illness in the 20 years since she started singing.