Hierarchical fluctuation shapes a dynamic flow linked to states of consciousness.

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.

Study at a glance

Abstract

Consciousness arises from the spatiotemporal neural dynamics, however, its relationship with neural flexibility and regional specialization remains elusive. We identified a consciousness-related signature marked by shifting spontaneous fluctuations along a unimodal-transmodal cortical axis. This simple signature is sensitive to altered states of consciousness in single individuals, exhibiting abnormal elevation under psychedelics and in psychosis. The hierarchical dynamic reflects brain state changes in global integration and connectome diversity under task-free conditions. Quasi-periodic pattern detection revealed that hierarchical heterogeneity as spatiotemporally propagating waves linking to arousal. A similar pattern can be observed in macaque electrocorticography. Furthermore, the spatial distribution of principal cortical gradient preferentially recapitulated the genetic transcription levels of the histaminergic system and that of the functional connectome mapping of the tuberomammillary nucleus, which promotes wakefulness. Combining behavioral, neuroimaging, electrophysiological, and transcriptomic evidence, we propose that global consciousness is supported by efficient hierarchical processing constrained along a low-dimensional macroscale gradient.