Cross-Species Evidence for Psilocin-Induced Visual Distortions: Apparent Motion Is Perceived by Both Humans and Rats.
Čestmír Vejmola, Klára Šíchová, Kateřina Syrová, Lucie Janeckova, Vlastimil Koudelka, Michael Tesař, Marek Nikolič, Michaela Viktorinová, Filip Tylš, Jakub Korčák, Vojtěch Viktorin, Eduard Kelemen, Tereza Nekovářová, Martin Brunovský, Jiří Horáček, Martin Kuchař, Tomáš Páleníček
Biological Psychiatry Global Open Science September 1, 2025 DOI: 10.1016/j.bpsgos.2025.100524 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Human participants and male rats |
| Intervention | Psilocin |
| Topics | Psilocybin |
| Keywords | Human Psychedelics Rat Visual hallucinations Psilocin vision impairment Psychedelic vision research |
| Citations | 4 |
| Key findings | Psilocin impairs static-dynamic visual discrimination in both humans and rats, with the impairment in humans correlating with psilocin plasma levels and hallucination intensity, and in rats selectively affecting motion-based perception. |
Abstract
Psychedelics, particularly psilocin, are increasingly being studied for their mind-altering effects and potential therapeutic applications in psychiatry. Visual hallucinations, especially the illusion of motion in static images, are a hallmark of their action. Despite growing interest, the underlying mechanisms remain poorly understood, as their systematic evaluation in both humans and animals is challenging. To investigate psilocin-induced visual distortions, we designed a 2-choice visual discrimination task. Human participants and male rats indicated whether an image appeared static or moving while the image either actually moved or did not. In humans, performance was compared with self-reported hallucination intensity, Altered States of Consciousness scale scores, and psilocin plasma levels. Rats were tested in 2 distinct tasks, a luminance-based task and a motion-based task. Their performance was evaluated alongside decision time. Both species exhibited significant impairment in distinguishing static from dynamic visual stimuli while under psilocin's influence. In humans, this impairment followed the time course of psilocin plasma levels and hallucination intensity. In rats, psilocin selectively impaired performance in the motion-based task, while performance in the luminance-based task remained intact, indicating a specific effect on visual perception. Decision time was linked to discrimination impairment. Psilocin impaired static-dynamic discrimination in both species, providing the first evidence that rats experience visual distortions similar to those reported by humans. The correlations between discrimination impairment, psilocin levels, and hallucination intensity in humans reinforce psilocin's effects on visual perception. This approach provides a valuable tool for investigating the neurobiology of altered visual perception in drug-induced states and psychiatric conditions.