Psilocybin alters visual contextual computations.
Nature communications – November 21, 2025
Source: PubMed
Summary
Psilocybin fundamentally shifts how the brain processes visual context, offering a clearer understanding of its effects. Using visual illusions, advanced brain imaging, and computer models, researchers investigated how psilocybin alters perception and brain dynamics. They discovered it changes how people perceive contextual visual cues and modifies brain responses. This highlights that altering contextual computations is a key mechanism underlying psychedelic action.
Abstract
Psilocybin alters perception and brain dynamics. Here, we investigate the effects of psilocybin using psychophysics, ultra-high field functional MRI, and computational modeling. We find that psilocybin alters contextual perception in the Ebbinghaus illusion, as well as contextual modulation in cortical responses to visual stimuli. We propose a computational model capable of capturing and linking these changes. Leveraging vision as a beachhead, our findings highlight the alteration of contextual computations as a potential general mechanism underlying psychedelic action.