A predictive coding framework of allostatic–interoceptive overload in frontotemporal dementia

Recent allostatic–interoceptive explanations using predictive coding models propose that efficient regulation of the body’s internal milieu is necessary to correctly anticipate environmental needs. We review this framework applied to understanding behavioral variant frontotemporal dementia (bvFTD) considering both allostatic overload and interoceptive deficits. First, we show how this framework could explain divergent deficits in bvFTD (cognitive impairments, behavioral maladjustment, brain atrophy, fronto-insular-temporal network atypicality, aberrant interoceptive electrophysiological activity, and autonomic disbalance). We develop a set of theory-driven predictions based on levels of allostatic interoception associated with bvFTD phenomenology and related physiopathological mechanisms. This approach may help further understand the disparate behavioral and physiopathological dysregulations of bvFTD, suggesting targeted interventions and strengthening clinical models of neurological and psychiatric disorders. Allostatic–interoceptive predictive coding frameworks suggest that regulation of the body’s internal milieu is required to predict and meet the needs generated from environmental demands before they arise.A multilevel organization of allostatic–interoceptive measures is proposed across cerebral, cardiocerebral, peripheral, and psychological levels.Behavioral variant frontotemporal dementia (bvFTD) is characterized by disparate autonomic, behavioral, and pathophysiological manifestations that seem to parallel multilevel measures of an allostatic–interoceptive overload.Under a predictive coding model, the allostatic–interoceptive deficits are explained by a mismatch between top-down and bottom-up predictions and prediction errors at multilevel hierarchies impaired in bvFTD, providing a novel framework for characterization, diagnosis, and interventions in bvFTD patients.