Orienting in a defensive world: mammalian modifications of our evolutionary heritage. A Polyvagal Theory

Cognitive influences on human autonomic nervous system function

Recent studies of human autonomic nervous system function have challenged the traditional view that the parasympathetic and sympathetic branches have opposite effects. In addition, studies of autonomic activity that accompanies attention, orienting and learning have demonstrated that the autonomic nervous system is not simply a 'non-cognitive' and automatic part of brain function. The autonomic and central nervous systems are intimately related, and new research is beginning to link brain function with autonomic function in a dynamic way.