Modulating the Rate and Rhythmicity of Perceptual Rivalry Alternations with the Mixed 5-HT2A and 5-HT1A Agonist Psilocybin
Olivia Carter, John D. Pettigrew, Felix Hasler, Guy Wallis, Guang B. Liu, Daniel Hell, Franz X. Vollenweider
Neuropsychopharmacology January 26, 2005 DOI: 10.1038/sj.npp.1300621 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Within-subjects, placebo-controlled experiment Peer reviewed |
|---|---|
| Sample size | 12 |
| Population | Healthy human volunteers |
| Intervention | Psilocybin (4-phosphoryloxy-N |
| Dose | 115 µg/kg and 250 µg/kg |
| Duration | 360 minutes postadministration |
| Topics | Psilocybin Serotonin |
| Keywords | Agonist Rivalry Hallucinogen Perception Cognitive psychology |
| Citations | 122 |
| Key findings | Psilocybin reduces the rate and rhythmicity of binocular rivalry alternations at peak drug action, with later increases in switch rate, suggesting serotonergic involvement in perceptual rivalry. |
Abstract
Binocular rivalry occurs when different images are presented simultaneously to corresponding points within the left and right eyes. Under these conditions, the observer's perception will alternate between the two perceptual alternatives. Motivated by the reported link between the rate of perceptual alternations, symptoms of psychosis and an incidental observation that the rhythmicity of perceptual alternations during binocular rivalry was greatly increased 10 h after the consumption of LSD, this study aimed to investigate the pharmacology underlying binocular rivalry and to explore the connection between the timing of perceptual switching and psychosis. Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine, PY) was chosen for the study because, like LSD, it is known to act as an agonist at serotonin (5-HT)1A and 5-HT2A receptors and to produce an altered state sometimes marked by psychosis-like symptoms. A total of 12 healthy human volunteers were tested under placebo, low-dose (115 microg/kg) and high-dose (250 microg/kg) PY conditions. In line with predictions, under both low- and high-dose conditions, the results show that at 90 min postadministration (the peak of drug action), rate and rhythmicity of perceptual alternations were significantly reduced from placebo levels. Following the 90 min testing period, the perceptual switch rate successively increased, with some individuals showing increases well beyond pretest levels at the final testing, 360 min postadministration. However, as some subjects had still not returned to pretest levels by this time, the mean phase duration at 360 min was not found to differ significantly from placebo. Reflecting the drug-induced changes in rivalry phase durations, subjects showed clear changes in psychological state as indexed by the 5D-ASC (altered states of consciousness) rating scales. This study suggests the involvement of serotonergic pathways in binocular rivalry and supports the previously proposed role of a brainstem oscillator in perceptual rivalry alternations and symptoms of psychosis.
Comparable studies
Other randomized controlled trials on serotonin, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Acute psychological and physiological effects of psilocybin in healthy humans: a double-blind, placebo-controlled dose?effect study Healthy human subjects | 2004 | Randomized controlled trial | n = 8 |
| Dose-Response Study of N,N-Dimethyltryptamine in Humans Experienced hallucinogen users | 1994 | Double-blind, saline placebo-controlled, randomized study | n = 12 |
| Acute Effects of Lysergic Acid Diethylamide in Healthy Subjects Healthy subjects (8 women, 8 men) | 2014 | Double-blind, randomized, placebo-controlled, crossover study | n = 16 |
| Changes in global and thalamic brain connectivity in LSD-induced altered states of consciousness are attributable to the 5-HT2A receptor Healthy human participants | 2018 | Double-blind, randomized, counterbalanced, cross-over study | n = 24 |
| Activation of Serotonin 2A Receptors Underlies the Psilocybin-Induced Effects on Oscillations, N170 Visual-Evoked Potentials, and Visual Hallucinations Healthy human subjects | 2013 | Randomized controlled trial |
Citations in the library
Cited by 55
- Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance Psychopharmacology July 7, 2006
- Human hallucinogen research: guidelines for safety. Journal of Psychopharmacology July 1, 2008
- REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics Pharmacological Reviews June 20, 2019
- Mystical-type experiences occasioned by psilocybin mediate the attribution of personal meaning and spiritual significance 14 months later Journal of Psychopharmacology May 30, 2008
- Acute, subacute and long-term subjective effects of psilocybin in healthy humans: a pooled analysis of experimental studies Journal of Psychopharmacology September 20, 2010
and 50 more in the library
Cites 9
- Psilocybin induces schizophrenia-like psychosis in humans via a serotonin-2 agonist action Neuroreport December 1, 1998
- The Standardized Psychometric Assessment of Altered States of Consciousness (ASCs) in Humans Pharmacopsychiatry July 1, 1998
- Acute psychological and physiological effects of psilocybin in healthy humans: a double-blind, placebo-controlled dose?effect study Psychopharmacology March 1, 2004
- Investigating neural correlates of conscious perception by frequency-tagged neuromagnetic responses Proceedings of the National Academy of Sciences March 17, 1998
- A Common Oscillator for Perceptual Rivalries? Perception March 1, 2003
and 4 more in the library