Effects of ayahuasca on binocular rivalry with dichoptic stimulus alternation
Psychopharmacology April 1, 2004 E. Frecska, K. D. White, L. E. Luna 31 citations
Binocular rivalry occurs when each eye is shown a different image, and the brain alternates which one is consciously perceived. A variant called dichoptic stimulus alternation (DSA) rapidly swaps the images between eyes, typically disrupting rivalry. This study tested whether the psychedelic brew ayahuasca alters this effect. Ten volunteers performed binocular rivalry tests at DSA rates of 0, 3.75, 7.5, 15, and 30 Hz before and after drinking ayahuasca. After ingestion, mean dominance periods—the time one image is perceived—increased under standard conditions and at all DSA rates. At the highest rates (15 and 30 Hz), dominance periods were longer on ayahuasca, suggesting the brew helps maintain rivalry where it would normally break down, possibly due to slowed visual processing and altered gamma oscillations.