Friday, August 03, 2012

Stephen Porges - The polyvagal theory: Phylogenetic substrates of a social nervous system

The title of this paper sounds pretty geeky, and it really kind of is geeky. Stephen Porges' Polyvagal Theory, however, is an immensely important and under-recognized element in understanding and treating trauma.

In light of the earlier post from today, I thought I'd share this paper (openly available online), as well as two interviews, one in text and one with Shrink Rap Radio. There is also a book that lays out the whole theory, The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation.

The polyvagal theory: phylogenetic substrates of a social nervous system

Stephen W. Porges

Department of Psychiatry, Uni ersity of Illinois at Chicago, 1601 W. Taylor Street, Chicago, IL 60612-7327, USA

The evolution of the autonomic nervous system provides an organizing principle to interpret the adaptive significance of physiological responses in promoting social behavior. According to the polyvagal theory, the well-documented phylogenetic shift in neural regulation of the autonomic nervous system passes through three global stages, each with an associated behavioral strategy. The first stage is characterized by a primitive unmyelinated visceral vagus that fosters digestion and responds to threat by depressing metabolic activity. Behaviorally, the first stage is associated with immobilization behaviors. The second stage is characterized by the sympathetic nervous system that is capable of increasing metabolic output and inhibiting the visceral vagus to foster mobilization behaviors necessary for ‘fight or flight’. The third stage, unique to mammals, is characterized by a myelinated vagus that can rapidly regulate cardiac output to foster engagement and disengagement with the environment. The mammalian vagus is neuroanatomically linked to the cranial nerves that regulate social engagement via facial expression and vocalization. As the autonomic nervous system changed through the process of evolution, so did the interplay between the autonomic nervous system and the other physiological systems that respond to stress, including the cortex, the hypothalamic -pituitary adrenal axis, the neuropeptides of oxytocin and vasopressin, and the immune system. From this phylogenetic orientation, the polyvagal theory proposes a biological basis for social behavior and an intervention strategy to enhance positive social behavior.
Porges, S. (20010). The polyvagal theory: Phylogenetic substrates of asocial nervous system. International Journal of Psychophysiology, 42; 123 -146.

See also: The Polyvagal Theory for Treating Trauma, an interview with Dr. Ruth Buczynski, PhD for the National Institute for the Clinical Application of Behavioral Medicine.

And finally, Dr. David Van Nuys interviewed Dr. Porges in June of 2011 for Shrink Rap Radio.

#265 – The Polyvagal Theory with Stephen Porges, Ph.D.

Stephen W. Porges, PhD is Professor of Psychiatry and BioEnginneering and Director of the Brain-Body Center at the University of Illinois at Chicago. His work on the autonomic nervous system has led to a new understanding of mechanisms involved in behavioral regulation and social engagement behaviors. He is developing new biobehavioral assessment tools to monitor individual differences in physiological regulation of behavioral state.

His research has led to an innovative intervention, The Listening Project, designed to exercise the neural regulation of middle ear structures to reduce auditory hypersensitivities and to improve the ability to listen and to attend to human speech. Dr. Porges speaks throughout the world about his Polyvagal Theory and its applications to typical and clinical populations. He is the author of the 2011 book, The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation.

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