Visceral afferent training in action: The origins of agency in early cognitive development

The foetal period constitutes a critical stage in the construction and organisation of the mammalian nervous system. In recent work, we have proposed that foetal brain development is structured by bottom-up (interoceptive) inputs from spontaneous physiological rhythms such as the heartbeat (Corcoran et al., 2023). Here, we expand this 'visceral afferent training' hypothesis to incorporate the development of top-down (allostatic) control over bodily states. We conceptualise the emergence of cardiac regulation as an early instance of sensorimotor contingency learning that scaffolds the development of agentic control. We further propose that the brain's capacity to actively modify and regulate the afferent feedback it receives through interoceptive channels - and to parse these signals into their self-generated (reafferent) and externallygenerated (exafferent) components - is crucial for grounding the distinction between self and other. Finally, we explore how individual differences in the ways these training regimes are implemented (or disrupted) might impact developmental trajectories in gestation and infancy, potentiating neurobehavioural diversity and disease risk in later life.