Psychoneurobiological Substantiation for the Behavioural Intervention Analysis (BIA) Framework in Autism

This manuscript proposes a Psychoneurobiological substantiation for the Behavioral Intervention Analysis (BIA) framework, fundamentally re-conceptualizing Restricted and Repetitive Behaviors (RRBs) in Autism Spectrum Disorder (ASD) from pathological deficits to emergent, adaptive, regulatory strategies.Integrating multi-level evidence, the framework anchors RRBs in predictable neural dysfunction: specifically, altered Cortico-Striatal-Thalamo-Cortical (CSTC) circuits and local Excitatory/Inhibitory (E/I) imbalance. These mechanisms manifest behaviorally as a necessary function to minimize prediction error and stabilize autonomic arousal in a system constrained by atypical sensory processing. Furthermore, RRBs, particularly in the social context, are conceptualized as a Compensatory Communicative Mechanism to manage the high computational load of social uncertainty.The framework enables trans-diagnostic mechanistic classification by using multimodal biomarkers—such as MRS-measured E/I ratios in specific cortices, Mismatch Negativity (MMN) for sensory prediction error, and high-resolution Heart Rate Variability (HRV)—to precisely map a behavior's function (e.g., sensory gain vs. affective hyper-arousal) to its underlying circuit locus.The central translational outcome is the Preserve-Regulate-Modify (PRM) intervention model. The framework's core testable prediction is the causal decoupling of symptom from function: successful PRM-based substantiation will lead to improved physiological regulation (e.g., increased cardiac vagal tone) even if overt RRB frequency remains stable, thereby empirically rejecting the traditional suppression-focused deficit model. This work provides a mechanism-informed, ethically-sound foundation for precision therapeutics in neurodevelopmental conditions.