Psilocybin alters visual processing and conscious perception in humans through serotonergic mechanisms, with implications for hallucinations and predictive brain models

Psilocybin changes visual perception and conscious experience in humans in ways that help clarify how serotonergic psychedelics produce hallucination-like effects. The research centers on altered sensory processing, shifts in perceptual organization, and the role of 5-HT2A receptor signaling in shaping what reaches awareness. The findings connect subjective visual changes to measurable effects on perception, suggesting that psilocybin does not merely intensify imagery but can reorganize how incoming sensory information is interpreted. That framework fits predictive processing models in which top-down expectations and bottom-up signals become differently weighted under psychedelics. Hallucination research, consciousness science, and translational psychiatry all gain from this approach because psilocybin offers a controlled way to study how the brain constructs visual reality. The broader implication is that psychedelic states can function as experimental models for probing perception, belief formation, and the neural basis of conscious awareness.