RT Journal Article SR Electronic T1 Exploring the effect of microdosing psychedelics on creativity in an open-label natural setting JF bioRxiv FD Cold Spring Harbor Laboratory SP 384412 DO 10.1101/384412 A1 Luisa Prochazkova A1 Dominique P. Lippelt A1 Lorenza S. Colzato A1 Martin Kuchar A1 Zsuzsika Sjoerds A1 Bernhard Hommel YR 2018 UL http://biorxiv.org/content/early/2018/08/11/384412.abstract AB Introduction Recently popular sub-perceptual doses of psychedelic substances such as truffles, referred to as microdosing, allegedly have multiple beneficial effects including creativity and problem solving performance, potentially through targeting serotonergic 5-HT2A receptors and promoting cognitive flexibility, crucial to creative thinking. Nevertheless, enhancing effects of microdosing remain anecdotal, and in the absence of quantitative research on microdosing psychedelics it is impossible to draw definitive conclusions on that matter. Here, our main aim was to quantitatively explore the cognitive-enhancing potential of microdosing psychedelics in healthy adults.Methods During a microdosing event organized by the Dutch Psychedelic Society, we examined the effects of psychedelic truffles (which were later analyzed to quantify active psychedelic alkaloids) on two creativity-related problem-solving tasks: the Picture Concept Task assessing convergent thinking, and the Alternative Uses Task assessing divergent thinking. A short version of the Ravens Progressive Matrices task assessed potential changes in fluid intelligence. We tested once before taking a microdose and once while the effects were manifested.Results We found that both convergent and divergent thinking performance was improved after a non-blinded microdose, whereas fluid intelligence was unaffected.Conclusion While this study provides quantitative support for the cognitive enhancing properties of microdosing psychedelics, future research has to confirm these preliminary findings in more rigorous placebo-controlled study designs. Based on these preliminary results we speculate that psychedelics might affect cognitive metacontrol policies by optimizing the balance between cognitive persistence and flexibility. We hope this study will motivate future microdosing studies with more controlled designs to test this hypothesis.We would like to thank the Psychedelic Society of the Netherlands for providing us with the opportunity to do the experiment at one of their events and Eliska Prochazkova for helping carrying out the experiment.This research was partly funded by an Advanced Grant of the European Research Council (ERC-2015-AdG-694722) to BH.