The 5-HT2A/1A Agonist Psilocybin Disrupts Modal Object Completion Associated with Visual Hallucinations
Biological Psychiatry December 4, 2010 Michael Kometer, B. Rael Cahn, David Andel et al. 101 citations
The hallucinogenic compound psilocybin, which activates 5-HT2A/1A serotonin receptors, alters how the brain processes visual information. In a placebo-controlled experiment with 17 healthy volunteers, psilocybin dose-dependently reduced the N170 brain response, especially when viewing incomplete object figures, while slightly enhancing the P1 component over occipital areas. The reduction in N170-related brain activity in the right extrastriate and posterior parietal regions correlated with the intensity of visual hallucinations. These findings point to a central role of 5-HT2A/1A receptors in visual processing and suggest that a diminished N170 response may be a key mechanism underlying visual hallucinations.