Effects of the Amazonian psychoactive beverage Ayahuasca on binocular rivalry: interhemispheric switching or interhemispheric fusion?
An early theoretical analysis supposed changes in hemispheric integration as the basis of altered state of consciousness induced by psychoactive drugs. Brain imaging studies revealed right cortical activation after administration of hallucinogens. Recent studies on binocular rivalry suggest that interhemispheric switching is the neural substrate of the perceptual oscillations observed during dichoptic stimulus presentation. The current study tested perceptual alternation in ceremonial participants, who ingested the South American hallucinogenic beverage ayahuasca, to examine the claim that there might be changes in interhemispheric function under the influence of hallucinogens. Ingestion of ayahuasca resulted in a decrease of rivalry alternation rates, increased length of one percept and there was evidence of phenomenal fusion. The findings are in line with results of brain activation studies and support the concept of interhemispheric fusion in altered states of consciousness.
Frecska
Ede
E
Wasiwaska Research Center for the Study of Psychointegrator Plants, Visionary Art and Consciousness, Florianópolis, SC, Brazil.
White
Keith D
KD
Luna
Luis E
LE
D000328:Adult; D000368:Aged; D031581:Banisteriopsis / Q000737:chemistry*; D001628:Beverages; D004292:Dominance, Cerebral / Q000187:drug effects* / Q000502:physiology; D023882:Dominance, Ocular / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006213:Hallucinogens / Q000009:adverse effects* / Q000494:pharmacology; D006247:Harmine / Q000009:adverse effects / Q000494:pharmacology; D006801:Humans; D008297:Male; D008875:Middle Aged; D028321:Plant Preparations / Q000009:adverse effects / Q000494:pharmacology; D015348:Vision, Binocular / Q000187:drug effects* / Q000502:physiology; D014796:Visual Perception / Q000187:drug effects* / Q000502:physiology
D006213:Hallucinogens; D028321:Plant Preparations; D006247:Harmine