Using psilocybin to investigate the relationship between attention, working memory and the serotonin 5-HT1A and 5-HT2A receptors
Journal of Vision – March 17, 2010
Source: OpenAlex
Summary
A compelling finding in psychology and neuroscience reveals that the hallucinogen psilocybin, a chemical synthesis and alkaloid, significantly impairs attention. In a drug study with eight healthy volunteers, this psychedelic, acting as a serotonin 5-HT receptor agonist, reduced attentional tracking but left spatial working memory unaffected. Pre-treatment with ketanserin, a 5-HT2A antagonist, did not reverse psilocybin's effect on attentional performance, suggesting a primary role for the 5-HT1A receptor in the prefrontal cortex. This neurotransmitter receptor influence on behavior highlights a dissociation in cognitive psychology, possibly reflecting a reduced ability to ignore distractions.
Abstract
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 5-HT1A/2A receptor agonist psilocybin alone and after pretreatment with the 5-HT2A antagonist ketanserin on multiple object tracking and spatial working memory, in eight healthy human volunteers. Psilocybin significantly reduced attentional tracking ability, but had no significant effect on spatial working memory, suggesting a functional dissociation between the two tasks. In line with the 5-HT1A receptor's known role in modulating prefrontal activity, 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. Based on physiological and pharmacological data, we propose that this impaired attentional performance may reflect reduced ability to suppress or ignore distracting stimuli rather than reduced attentional capacity.