Vollenweider Hasler

Fakultäten » Medizinische Fakultät » Psychiatrische Universitätsklinik » Psychiatrie, Psychotherapie und Psychosomatik, Klinik für » Prof. Dr. Daniel Hell (emeritiert) » Vollenweider Hasler

Completed research project

Title / Titel Effect of the preferential 5-HT2A Agonist Psilocybin on Working Memory, Time Reproduction and Rhythmicity of Perceptual Rivalry
PDF Abstract (PDF, 14 KB)
Summary / Zusammenfassung Understanding the neural basis of consciousness has long been a goal of neuroscientists. To this end, considerable attention has been focused recently on different forms of perceptual rivalry as it is a phenomenon characterized by switches in perception that occur despite a constant, if ambiguous, sensory input. Binocular rivalry is a specific form of perceptual rivalry that results when two different images are simultaneously presented to the corresponding retinal location in the left and right eye (Walker 1975). Under these conditions the observer will experience alternations between awareness and suppression of the two ‘rivaling’ images.

More recently it has been shown that deviations from the norm in rivalry rate correspond with symptoms of psychosis (Miller et al. 2003; Pettigrew and Miller 1998). Together with other findings this result supports the appraisal that perceptual switches of rivalry reflect the activity of an oscillator, whose rhythms are fundamental to a number of brain functions and associated states of consciousness (Pettigrew and Carter 2004). Moreover, there is preliminary evidence that the switching rate of perceptual rivalry is modulated by activation of the serotonergic and/or dopmaminergic system (Carter and Pettigrew 2003).

To further assess the role of the serotonin system (particularly of the 5-HT2A receptor) on perceptual rivalry and time reproduction, the effect of the preferential 5-HT2A receptor agonist psilocybin on rhythmicity of binocular rivalry alternations and its relation to psychotic symptom formation shall be tested in healthy human subjects. Subsequent comparison studies in incipient schizophrenia patients shall help to clarify whether binocular rivalry measures can be used as an index of early visual disturbances in psychosis.
Publications / Publikationen Wittmann M, Carter OL, Hasler F, Cahn BR, Grimberg U, Spring P, Hell D, Flohr H, Vollenweider FX (2007) Effects of psilocybin on time perception and temporal control of behaviour in humans. J Psychopharmacology 21: 50-64

Carter OL, Pettigrew JD, Burr DC, Alais D, Hasler F, Vollenweider FX (2004) Psilocybin impairs high-level but not low-level motion perception. Neuroreport 15: 1947-1951

Carter OL, Pettigrew JD, Hasler F, Wallis GM, Liu GB, Hell D, Vollenweider FX (2005) Modulating the rate and rhythmicity of perceptual rivalry alternations with the mixed 5-HT2A and 5-HT1A agonist psilocybin. Neuropsychopharmacology 30: 1154-1162

Carter OL, Burr DC, Pettigrew JD, Wallis GM, Hasler F, Vollenweider FX (2005) Using psilocybin to investigate the relationship between attention, working memory and the Serotonin 1A & 2A receptors. J Cog Neurosci 17: 1497-1508

Carter OL, Hasler F, Pettigrew JD, Wallis GM, Liu GB, Vollenweider FX (2007) Psilocybin links binocular rivalry switch rate to attention and subjective arousal levels in humans. Psychopharmacology 195: 415-424

Keywords / Suchbegriffe Binocular rivalry, working memory, time reproduction, cognition, psychosis, serotonin, HT2A receptor, psilocybin, healthy volunteers, human study
Project leadership and contacts /
Projektleitung und Kontakte
PD Dr. F.X. Vollenweider (Project Leader)
Dr. F. Hasler (Project Leader)
Dr. O. Carter
Funding source(s) /
Unterstützt durch
Heffter Research Center Zürich; Generation Research Program Bad Tölz, Human Science Center, Ludwig-Maximilian University of Munich; Research Development Grant, University of Queensland, Australia
In collaboration with /
In Zusammenarbeit mit
John D. Pettigrew, Vision, Touch and Hearing Research Centre, School of Biomedical Sciences, University of Queensland, Australia Australia
Marc Wittmann, Generation Research Program Bad Tölz, Human Science Center, Ludwig-Maximilian University of Munich, Prof.-Max-Lange-Platz 11, 83646 Bad Tölz, Germany Germany
Duration of Project / Projektdauer Apr 2003 to Apr 2007