Psilocybin's acute perceptual psychedelic effects may arise from drug-level decreases in the occurrence and duration of lateral and medial frontoparietal connectivity motifs. The authors apply and argue for a modified approach to modeling eigenvectors from LEiDA that more fully acknowledges their underlying structure. These findings contribute to a more comprehensive neurobiological framework underlying acute effects of serotonergic psychedelics.
After a psychedelic dose of psilocybin, the occurrence and duration of two brain states involving lateral frontoparietal and medial fronto-parietal-cingulate coherence decrease, while a fully connected brain state increases. These changes are associated with both the level of psilocin in the blood and the intensity of the subjective drug experience. The findings suggest that the acute perceptual effects of psilocybin may arise from a shift away from specific frontoparietal connectivity motifs toward a more uniform connectivity structure. The study also proposes an improved method for modeling brain states from dynamic functional connectivity data.