Researchers studied how psilocybin affects the way our visual system processes contrast and surrounding visual information. Participants completed vision tests after taking psilocybin or placebo, and the results showed that psilocybin made people more influenced by surrounding visual elements when judging the brightness of objects. Interestingly, the stronger the visual effects people experienced from psilocybin, the more their perception was influenced by these surroundings. This finding might help explain how psilocybin affects mood and could help scientists better understand depression and other conditions affecting vision.