Using Psilocybin to Investigate the Relationship between Attention, Working Memory, and the Serotonin 1A and 2A Receptors

This study tested the effects of psilocybin (15mg/70kg) on attentional tracking and spatial working memory, using a placebo-controlled design and ketanserin pretreatment condition to control for the 5-HT2A specific effects. Results indicated reduced attentional tracking ability, but unimpaired working memory, which was not related to 5-HT2A activity.

Abstract

Introduction: “Increasing evidence suggests a link between attention, working memory, serotonin (5-HT), and prefrontal cortex activity. In an attempt to tease out the relationship between these elements, this study tested the effects of the hallucinogenic mixed 5-HT1A/2A receptor agonist psilocybin alone and after pretreatment with the 5-HT2A antagonist ketanserin.

Methods: Eight healthy human volunteers were tested on a multiple-object tracking task and spatial working memory task under the four conditions: placebo, psilocybin (215 Ag/kg), ketanserin (50 mg), and psilocybin and ketanserin.

Results: Psilocybin significantly reduced attentional tracking ability, but had no significant effect on spatial working memory, suggesting a functional dissociation between the two tasks. Pretreatment with ketanserin did not attenuate the effect of psilocybin on attentional performance, suggesting a primary involvement of the 5-HT1A receptor in the observed deficit.

Discussion: Based on physiological and pharmacological data, we speculate that this impaired attentional performance may reflect a reduced ability to suppress or ignore distracting stimuli rather than reduced attentional capacity. The clinical relevance of these results is also discussed.”

Authors: Olivia L. Carter, David C. Burr, John D. Pettigrew, Guy M. Wallis, Felix Hasler, Franz X. Vollenweider

Study details

Compounds studied
Psilocybin

Topics studied
Neuroscience

Study characteristics
Placebo-Controlled

Participants
8

Authors

Authors associated with this publication with profiles on Blossom

Franz Vollenweider
Franz X. Vollenweider is one of the pioneering psychedelics researchers, currently at the University of Zurich. He is also the director of the Heffter (sponsored) Research Center Zürich for Consciousness Studies (HRC-ZH).

Institutes

Institutes associated with this publication

University of Zurich
Within the Department of Psychiatry, Psychotherapy and Psychosomatics at the University of Zurich, Dr Mialn Scheidegger is leading team conducting psychedelic research and therapy development.

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