Using Psilocybin to Investigate the Relationship between Attention, Working Memory, and the Serotonin 1A and 2A Receptors
Olivia Carter, David C. Burr, John D. Pettigrew, Guy Wallis, Felix Hasler, Franz X. Vollenweider
Journal of Cognitive Neuroscience October 1, 2005 DOI: 10.1162/089892905774597191 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Sample size | 8 |
| Population | Healthy human volunteers |
| Interventions | Psilocybin Ketanserin |
| Dose | 215 μg/kg psilocybin, 50 mg ketanserin |
| Topics | Psilocybin Serotonin |
| Keywords | Ketanserin Working memory Hallucinogen Agonist Prefrontal cortex Cognitive psychology 5-HT Receptor Cognition |
| Citations | 236 |
| Key findings | Psilocybin significantly reduced attentional tracking ability but had no significant effect on spatial working memory, and ketanserin pretreatment did not block this attentional impairment. |
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.