Interoceptive autonomic regulation in typical development and autism spectrum disorder: A computational model integrating multiple physiological systems

BackgroundInteroceptive cardiovascular signals, including heart rate (HR) and blood pressure (BP), arise from coordinated sympathetic (SNS) and parasympathetic (PSNS) regulation and contribute to affective and cognitive processes. Although atypical autonomic nervous system (ANS) modulation has been reported in autism spectrum disorder (ASD), the dynamical structure underlying branch-specific coordination remains insufficiently characterized. ObjectiveTo estimate latent ANS regulatory structure in typically developing (TD) and ASD individuals using a computational modeling framework. MethodsA closed-loop computational model integrating cardiovascular, respiratory, and autonomic dynamics was developed. ANS regulation was formalized using three autonomic control modes (coupled reciprocal, coupled nonreciprocal, and uncoupled) and parameterized by the relative activity of SNS and PSNS branches. HR and BP responses to the head-up tilt (HUT) test were simulated, and regulatory surfaces were compared with empirical HR and BP data from TD and ASD groups. Additional simulations under normal respiration, deep respiration, and absence of respiration evaluated mean arterial pressure (MAP) regulation across varying SNS-PSNS activity combinations. ResultsTD individuals exhibited differentiated SNS-PSNS coordination patterns across control modes, whereas ASD individuals showed convergence of relative SNS-PSNS activity. In TD, HR and BP distributions under coupled reciprocal mode were most consistent with expected physiological responses, characterized by high SNS and low PSNS activity during postural challenge. In ASD, empirical data extended toward regions of relatively higher PSNS weighting. Incorporation of deep respiration enhanced MAP reduction during BP recovery, particularly under over-elevated SNS activity. ConclusionThis study provides a mechanistic, state-space characterization of autonomic coordination in TD and ASD populations, enabling inference of latent autonomic regulation from measurable interoceptive phenotypes and identifying respiration as a model-based regulatory lever that augments cardiovascular stabilization.