Using Psilocybin to Investigate the Relationship between Attention, Working Memory, and the Serotonin 1A and 2A Receptors
Journal of Cognitive Neuroscience – October 01, 2005
Source: OpenAlex
Summary
Psilocybin, a potent hallucinogen, significantly impairs attention, not working memory. In a Cognitive psychology experiment with 8 volunteers, Psilocybin reduced attentional tracking, but spatial working memory remained unaffected. This suggests a functional dissociation in cognitive processes. Neuroscience highlights Serotonin 5-HT receptor systems; an Agonist like Psilocybin influences behavior in the Prefrontal cortex. Ketanserin, used in Psychedelics and Drug Studies, didn't reverse the effect, suggesting 5-HT1A receptor involvement. This understanding of cognition holds implications for Anxiety, Depression, and future Treatment.
Abstract
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 mixed 5-HT1A/2A receptor agonist psilocybin alone and after pretreatment with the 5-HT2A antagonist ketanserin. 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. 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. 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.