A computational graph-theoretic analysis of the human structural connectome, incorporating subcortical structures including the brainstem, finds that the brainstem ranks highest across degree, eigenvector, and betweenness centrality metrics. The averaged connectome was derived from 100 healthy adult subjects using Python DIPY and Nibabel libraries. The results indicate the importance of including the brainstem in structural network analyses and suggest that such network-based methods can inform theories of consciousness, including global workspace theory, integrated information theory, and the thalamocortical loop theory.
The hard problem of consciousness—how subjective experience arises from brain matter—might be addressed by quantum physics. Quantum entanglement, which is both complex and unified, parallels the unity and complexity of subjective experience, unlike classical physics. The author proposes that subjective experience relates to the dynamics of a complex entangled state of spins, continuously generated and updated through photon exchange. Spins in condensed matter at body temperature can have coherence times relevant to experience (milliseconds to seconds). Neurons emit photons, likely from reactive oxygen species in mitochondria; opsins in the brain may detect single photons. Axons may act as photonic waveguides, and oxygen molecules could interface photons and spins. Photon rates appear sufficient for the bandwidth of subjective experience.