I have just published the preprint of a paper that follows directly from the seminal white paper establishing the new foundation model of Autonomics - Towards an Accurate In Vivo Reconceptualizing of Autonomic State - that provides a much finer-grained logic and neuroanatomical mapping to the revision of the actual neural cartography of the boundaries of the three autonomic systems.
A brief note is required here, at the level of taxonomy, because modern neuroscience is built on an antiquated model of the ANS – it still talks about autonomic balance and visualizes this as a seesaw - that Polyvagal Theory revised in 1994. The traditional model names the system as a binary (sympathetic, parasympathetic) and treats the enteric nervous system as a third autonomic system. So if you ask someone informed by the traditional model (like your physician) what the three branches of the ANS are, they will tell you sympathetic, parasympathetic, and enteric. By contrast, PVT recognizes that there are two parasympathetic systems, both vagal, one supra-diaphragmatic and one sub-diaphragmatic, which operate in coordination with a sympathetic system. Ask a Polyvagalist what the three autonomic systems are and they will tell you ventral vagal, dorsal vagal, and sympathetic. From the standpoint of naming convention, our taxonomy is more closely aligned with the Porgesian framing of this, yet it moves the neuro-anatomical commitments beyond what Porges made in necessary and meaningful ways because it 1) confronts and corrects category errors inherited by the field since inception, 2) understands the source-to-target principle of neural growth, 3) re-examines neuro-embryonic development in light of autonomic organization, and 4) re-engages relevant post-natal myelination timelines.
The paper explains why
the hands are missing but central components of what we call the CONNECTION SYSTEM and Porges calls ventral vagal, and gives several evidentiary points in support of this recognition, including neuroembryonic development and post-natal myelination timing
the feet are missing but crucial components of what we call the GROUNDING SYSTEM and Porges calls dorsal vagal, and gives several evidentiary points in support of this recognition, including neuroembryonic development and post-natal myelination timing
The Sympathetic Nervous System does not exist, has been mischaracterized in vertebrate neurophysiology for centuries, the specific category errors that gave rise to this mischaracterization, the specific corrections required to reconcile it with functional neuroanatomy and evolutionary developmental biology, and how this transformation impacts our understanding of the functions of this system.
It further elaborates why the construction of autonomic state is a 3-variable construction, and clarifies why pervading neurochemistry is the crucial unnamed variable acting on often context-neutral neurology to shape its function.
This paper contributes to elaborating the foundation model of autonomics, precedes a subsequent companion paper that refines the mechanisms governing autonomic coordination and decoupling in the creation of autonomic states – Cooperative Coordination and Hierarchical Decoupling: A Three-System Model of Autonomic State Construction - and will prove load-bearing as a reference document for our forthcoming paper that challenges both Polyvagal Theory and the Grossman et al. critique of the same, Breaking the Stasis in the Polyvagal Controversy.