Hierarchical Functional Shedding: A Connectivity-Maintenance Model of Higher-Order Integration Failure Across Acute Mania, General Anaesthesia, and Alzheimer's Disease

Abstract

Hierarchical Functional Shedding (HFS) is a connectivity-maintenance hypothesis developed to explain why higher-order cognitive integration may deteriorate while wakefulness, elementary perception, recognition, and overlearned behaviour remain comparatively preserved. The model proposes that, as usable neural maintenance capacity declines, operations that depend strongly on long-range communication, high-participation hubs, recurrent processing, and cross-network coordination may cross their stability thresholds before more local or automatic operations. The manuscript evaluates this hypothesis through a structured narrative synthesis of brain-network energetics and three distinct perturbation classes: acute mania, general anaesthesia, and Alzheimer’s disease. Acute mania illustrates state-dependent impairment of illness insight despite preserved wakefulness; general anaesthesia provides reversible evidence of distributed integration failure with relative preservation of local processing; and Alzheimer’s disease demonstrates chronic hub vulnerability and possible dissociation between cognitive performance and awareness of impairment. HFS is presented as a falsifiable threshold model rather than an established law. The paper distinguishes metacognition, clinical insight, behavioural responsiveness, global access, and phenomenal consciousness; addresses alternative explanations and methodological confounders; and proposes prospective tests using metacognitive efficiency, perturbational complexity, network integration, and metabolic imaging.