Interoception and the autonomic nervous system: Bottom-up meets top-down

Although the efferent role of the autonomic nervous system (ANS) in homeostasis has long been recognized, afferent aspects of the ANS—especially interoception—are increasingly recognized to be equally important. Interoception is fundamental to the regulation of internal physiology, particularly as it is coordinated with contextually determined and adaptive behavioral processes. A cardinal but often underappreciated feature of interoception is its role in myriad cognitive and affective processes that are integrated in health and disease. This chapter introduces the concept of interoception and outlines its historical origins and applications in multiple domains of psychology and psychobiology. It provides an overview of its peripheral and central neural substrates, and it outlines how this construct is best conceptualized within a multi-system and multi-level regulatory framework.