Polyvagal Theory is a comprehensive evolutionary model for understanding and treating anxiety and panic disorders.
General anxiety disorder and panic disorders are two of the most common mental conditions in Australia and around the world. The difference between the two is that anxiety disorders are mainly characterised by excessive worry brought about from perceived threats; whereas panic disorder is characterised by severe symptoms of anxiety that can lead to unexpected panic attacks at any time. Polyvagal theory, originally formulated by Dr Stephen Porges, provides a useful and integrative evolutionary framework for understanding these anxiety and panic responses. It also elevates social relationship as a primary means of coregulating and healing from these responses.
The Traditional Model
The nervous system can be divided simply into the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). The CNS consists of the brain, brainstem, and spinal cord while the PNS consists of the nervous system outside of them. The PNS can be further divided into the Somatic Nervous System (SNS) and the Autonomic Nervous System (ANS). The SNS is involved in conscious control of skeletal movement. The ANS, on the other hand, is an unconscious system that controls bodily processes such as heart rate and digesting. Breathing is the one consciously controlled autonomic process, so it is particularly important for shifting our physiological state.
Traditionally, the ANS is divided between the sympathetic and parasympathetic nervous system. The sympathetic nervous system is seen as the “fight-or-flight” system; whereas the parasympathetic nervous system is seen as the “rest-and-digest” system. Before the polyvagal theory, the commonly held belief was that the autonomic nervous system operated in just two states: stress and relaxation.
When the sympathetic nervous system is activated, we experience stress responses like sweating, discomfort, hyperventilation, palpitations, dizziness, tremors, chest discomfort, and GI distress. When the parasympathetic nervous system is activated, we experience relaxation responses like heart rate reduction, salivation, efficient digestion, and safe socialising.
The Updated Model: Polyvagal Theory
Neuroception: Signals of Safety or Danger
The nervous system uses a subconscious feature called neuroception to detect either safety or danger in others. Anxiety can be thought of as an overactive neuroception system, interpreting danger where there isn’t any danger. For our hunter-gatherer ancestors, danger meant a lion on the savannahs, or a neighbouring tribe throwing spears at us. In the modern times, the danger for sufferers of anxiety has been abstracted away, keeping anxiety sufferers in a near constant state of hypervigilance and threat detection with no clear resolution like the concrete threats our nervous system evolved around.
Depending on your autonomic state, your body transforms, and different systems in the polyvagal hierarchy are activated depending on the neuroception of safety or danger. This state is the filter through which you experience the world. The primary nerve responsible for this is the vagus nerve. The autonomic nervous system evolved to distinguish safe from unsafe social environments, and this is done primarily through the dual-branching vagus nerve. The vagus nerve connects together many different body parts and organs together as a coregulated system, with both ascending and descending signals.
The Green Light: Social Engagement System and the Ventral Vagus
The autonomic system is structured as a hierarchy from the top to bottom based on cues of safety or danger. The top system is the green system, the social engagement system, mediated by the ventral vagus. This is the most complex and evolved mammalian parasympathetic response, mediating (with other cranial nerves) relaxation signals like slow heart rate, better digestion, breath, and facial expressions. All of these work towards promoting healthy social connectedness and coregulation.
The Yellow Light: Danger and The Sympathetic Response
When we are not detecting the environment as safe, we fall into a sympathetic response. This is when vagal stimulation is overridden with sympathetic signalling. The “fight-or-flight” symptoms start to appear here: nervousness, sweaty palms, and fast heart rate, for instance.
The Red Light: Perceived Threats and The Dorsal Vagus
If the above sympathetic “fight-or-flight” system fails, we continue to feel unsafe, perhaps even to a life-threatening degree such as in panic attacks, and revert to a primitive immobilisation response mediated by the dorsal vagus nerve. This is an ancient evolutionary parasympathetic response with the intention of immobilisation and explains traumatic reactions such as freezing, dissociation, and fainting.
Harnessing the Ventral Vagal Connection
Feeling safe is absolutely crucial as social beings. It fosters general health and well-being, releases beneficial hormones like the cuddle hormone oxytocin, promotes learning, critical thinking and productivity, and overall makes life more relaxing and enjoyable.
One aspect of the ventral-vagus system is under our direct conscious control: breathing. Slow breathing, such as in the square breathing or diaphragmatic breathing technique, can help shift the scale towards a parasympathetic response which ripples out into the rest of the nervous system.
Positive environmental cues can also transform your physiology through safe, coregulating, and attuned socialising. Social connectedness is a biological imperative, like eating and sleeping, and in this way social behaviour is key to mental and physical health.
When you engage the green light, you create cycles of healing that are very effective in eliminating anxiety and panic. Safe parasympathetic responses further encourage safe parasympathetic responses, both from within and from the external social environment who are reading and responding with safe cues. Face-to-face engagement, eye contact, soothing or melodic voice (such as in ASMR) are all beneficial for tilting the balance towards the social engagement system. Sport, dancing, yoga, sex, art are all mobilising the social engagement system as well, and when we have exhausted ourselves, the body can fall into a safe form of immobilisation through rest, rejuvenation, meditation, and sleep.