Effects of ayahuasca on binocular rivalry with dichoptic stimulus alternation
E. Frecska, K. D. White, L. E. Luna
Psychopharmacology April 1, 2004 DOI: 10.1007/s00213-003-1701-x (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Within-subjects experimental study Peer reviewed |
|---|---|
| Sample size | 10 |
| Population | Individuals participating in ayahuasca ceremonials |
| Intervention | Ayahuasca |
| Topics | Ayahuasca |
| Keywords | Binocular rivalry Stimulus psychology Binocular vision Monocular Audiology Hallucinogen Visual perception Cognitive psychology Computer vision |
| Citations | 31 |
| Key findings | Ingestion of ayahuasca increased mean dominance periods in binocular rivalry, especially at high dichoptic stimulus alternation rates (15 and 30 Hz), where dominance periods were longer on the brew. |
Abstract
RationaleDuring binocular rivalry, two incompatible images are presented to each eye and these monocular stimuli compete for perceptual dominance, with one pattern temporarily suppressed from awareness. One variant of stimulus presentation in binocular rivalry experiments is dichoptic stimulus alternation (DSA), when stimuli are applied to the eyes in rapid reversals. There is preliminary report that in contrast with healthy controls, schizophrenic patients can maintain binocular rivalry even at very high DSA rates.ObjectiveThe study was undertaken to investigate whether binocular rivalry survives high rates of DSA induced by the South American hallucinogenic beverage ayahuasca.MethodsTen individuals who were participating in ayahuasca ceremonials were requested to volunteer for binocular rivalry tests (DSA=0, 3.75, 7.5, 15 and 30 Hz) without and after drinking the brew.ResultsIngestion of ayahuasca increased mean dominance periods both in standard binocular rivalry conditions (no DSA) and tests with DSA. At higher DSA rates (15 and 30 Hz) the total length of dominance periods was longer on the brew.ConclusionIt is discussed that ayahuasca-induced survival of binocular rivalry at high DSA rates may be related to slow visual processing and increased mean dominance periods may result from hallucinogen-induced alteration of gamma oscillations in the visual pathways.