Hierarchical fluctuation shapes a dynamic flow linked to states of consciousness.
Nature communications June 5, 2023 Ang Li, Haiyang Liu, Xu Lei et al.
Consciousness is linked to how neural activity shifts along a unimodal-transmodal cortical axis, a simple signature that is abnormally elevated under psychedelics and in psychosis. This hierarchical dynamic reflects changes in global brain integration and connectome diversity. Quasi-periodic patterns show hierarchical heterogeneity as spatiotemporally propagating waves tied to arousal, a pattern also seen in macaques. The spatial distribution of the principal cortical gradient aligns with genetic transcription of the histaminergic system and functional connectome mapping of the tuberomammillary nucleus, which promotes wakefulness. Combining behavioral, neuroimaging, electrophysiological, and transcriptomic evidence, the authors propose that global consciousness is supported by efficient hierarchical processing along a low-dimensional macroscale gradient.