Psilocybin alters visual cortex signaling so the brain responds as if it were seeing light, offering a neural explanation for vivid closed-eye visuals and hallucinations

Psilocybin changes activity in the visual brain in ways that resemble actual light entering the eyes, giving researchers a concrete neural account of why vivid imagery and hallucination-like visuals can arise even without external visual input. The central finding links psychedelic experience to altered signaling in visual circuits rather than to imagination alone. The study points to the visual cortex misclassifying internally generated activity as sensory information. That mechanism helps explain closed-eye visuals, intensified patterns, and the sense that perception has become unusually real or luminous. By tying subjective effects to measurable brain responses, the findings strengthen broader research into how psychedelics reshape perception, consciousness, and sensory processing. Psilocybin also becomes a model for probing how the brain decides what counts as real visual input. That matters for basic neuroscience as well as for understanding hallucinations across different states, from psychedelic sessions to psychiatric or neurological conditions.