EMDR Therapy Quarterly

If not exactly Polyvagal Theory for Dummies, Stephen Porges has in this book distilled his theory for non-scientists, and that includes therapists. It comprises a transcribed series of interviews with Porges in which he explains to readers the origins of his inquiry into this field and the immense practical value of the theory in understanding psychopathology. The format of recorded conversations makes it highly readable. The book provides a handy reference to the heart of the theory and why it is important in understanding the presentation and behaviour of our clients, particularly those with complex trauma.

In his preface Porges says he was surprised at the success of his earlier book: The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation [1]. This newer Pocket Guide is his attempt to respond to the many requests he has had to make his theory more readily accessible. “In writing this book”, Porges writes, “it is my hope to highlight the important role of feeling safe as an important component of the healing process. From a polyvagal perspective, deficits in feeling safe form the core biobehavioural feature that leads to mental and physical illness”.

The story really takes off when his research paper in Pediatrics showed that neonates with a good level of vagal activity (vagal tone) had good clinical outcomes. He measured the rhythmic increases and decreases in heart rate (respiratory sinus arrhythmia) associated with normal breathing in neonates and found that some babies’ heart rates were comparatively constant and did not correlate with respiratory patterns; these babies were at risk of serious complications.

A letter from a neonatal specialist following the publication of the Pediatrics paper signalled a whole new research direction and ultimately a paradigm shift in our understanding of how the autonomic nervous system functions. The doctor wrote that his training had warned about the potentially lethal influence of the vagus nerve; in neonates it could cause life-threatening slowing of the heart (bradycardia) and apnoea (cessation of breathing). His research question became: “how could the vagus be both protective when it was expressed as  respiratory sinus arrhythmia and life-threatening when it was expressed as bradycardia and apnoea?”.

Porges found the answer to the paradox in the evolution of the vagus nerve (more accurately conceived as a family of nerves). The earliest version comprises the part of the vagus below the diaphragm that causes immobilisation in response to life threatening situations. Oxygen consumption is conserved and the animal is rendered virtually lifeless. This is the dorsal vagal sub-system. The system we hear of most often in the stress response is fight/flight actions of the sympathetic nervous system, the part of the vagus above the diaphragm, activated to mobilise us in response to threat. These two sub-systems are defence systems.

But the most recent evolutionary development is the social engagement system (the ventral vagal system) comprising vagal pathways from the heart which connect with pathways that control muscles of the face and head. The latter regulate how we see, hear, speak and physically express emotions through the control of facial muscles. Importantly this most recent upgrade can override the other two systems, hence Porges’ focus on the feeling of safety at the heart of mental ill health.

Porges explains in this book how this information superhighway (the vagus nerve fibres carry information between brain and body) regulates our emotions. “When the social engagement system is working”, Porges writes, “it down-regulates defences and we feel calm, we hug people, we look at them and we feel good. However, when risk increases, the two defence systems take priority.”

Porges maintains that Polyvagal Theory has a great deal to offer not only in the realm of psychology but even in architecture. In other research he has shown how the dorsal vagal system is activated by low-frequency sounds (think of the fear-inspiring music of Jaws) and bemoans the fact that so many of our hospitals and clinics have rooms in which the low hum of air-conditioning and other infrastructure components stoke fear in patients rather than coaxing them into feelings of safety. We are hard-wired through the social engagement system to be affected by sounds of certain pitches. Prosody, the up-and-downness or inflections in speaking, signal safety. Monotones signal danger. An added reason of why it feels so good to sing, and even more so when we are singing in a choir.

The books is full of insights of value to therapists. My only quibble is that it could have been better edited and, despite Porges’ refutation of this in his preface, there is a lot of repetition of the same material in the various interviews. That aside, it is a very worthwhile read.

By Omar Sattaur