Systemic Architecture of Consciousness: Biological Convergence of the Striatal Hourglass, the Body Sensor, and Phylogenetic Conservation

This document presents a proposal for a theoretical synthesis of consciousness, integrating findings from evolutionary neurobiology, computational psychiatry, and the Free Energy Principle. Building upon the recent discovery of the "neural hourglass" mechanism in the motor cortex and striatum (Yang, Inagaki et al., Nature 2026), this proposal extends the metaphor to the domain of subjective experience. It hypothesizes that the striatum acts as a temporal integrator for interoceptive signals ("Body Sensor"), where consciousness emerges not from cortical complexity alone, but from the successful "gating" of affective urgency. The paper discusses implications for mental health, proposing that conditions like depression and psychosis may represent specific failures (pausing vs. rewinding) of this striatal hourglass.