Allostasis, interoception, and the free energy principle: Feeling our way forward

Interoceptive processing is commonly understood in terms of the monitoring and representation of the body’s current physiological (i.e. homeostatic) status, with aversive sensory experiences encoding some impending threat to tissue viability. However, claims that homeostasis fails to fully account for the sophisticated regulatory dynamics observed in complex organisms have led some theorists to incorporate predictive (i.e. allostatic) regulatory mechanisms within broader accounts of interoceptive processing. Critically, these frameworks invoke diverse – and potentially mutually inconsistent – interpretations of the role allostasis plays in the scheme of biological regulation. We argue in favour of a moderate, reconciliatory position in which homeostasis and allostasis are conceived as equally vital (but functionally distinct) modes of physiological control. We explore the implications of this interpretation for free energy-based accounts of interoceptive inference, advocating a similarly complementary (and hierarchical) view of homeostatic and allostatic processing.