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

Olivia L. Carter, David C. Burr, John D. Pettigrew, Guy M. Wallis, Felix Hasler, Franz X. Vollenweider
2005 Journal of Cognitive Neuroscience  
& 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-HT 1A/2A receptor agonist psilocybin alone and after pretreatment with the 5-HT 2A antagonist ketanserin. Eight healthy human volunteers were tested on a multiple-object tracking task and spatial working memory task under the four conditions:
more » ... o, 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-HT 1A 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. &
doi:10.1162/089892905774597191 pmid:16269092 fatcat:hayqpytmz5ci3cqrsffy4m46d4