Interoception in normative development and the drive toward agency: Relevance for understanding aspects of...

A coherent and unified sense of ownership (the sense that "I" am a unified entity that is undergoing experiences) and of agency (the sense that "I" am causing actions and responsible for their effects) are fundamental human characteristics. Initial rhythmic visceral signals (primarily cardiac) early in the lifespan, may be an embryonic scaffold on which functionally well-organized brain networks are formed. These rhythmic visceral dynamics allow the brain to train itself to model physiological sensations within the body. These visceral afferent signals are precursors of interoception, which is the brain's ability to interpret internal physiological states and eventually develop action plans in the world. Together interoception and exteroception (the complementary ability to sense, process and respond to external events) contribute to a fully formed neural system which can distinguish the internal (to the body) from the external (in the world). This set of ideas are relevant in thinking about a disorder like schizophrenia. Schizophrenia is characterized by deficits in ownership, agency, interoception and exteroception, but their bases have not been conceptually linked. Our attempted synthesis suggests that disruptions in visceral afferent training are the first in a cascade of aberrant neurodevelopmental processes that eventually manifest as schizophrenia. The paper attempts to pull together concepts that link schizophrenia to aberrant neurodevelopment, brain network dysconnection, impaired interoception and disturbed agency. When further elaborated upon, this synthesis may allow us to interpret the clinical and cognitive deficits that define the disorder's core and expand interest in the study of interoception in schizophrenia.