Exploring the effect of microdosing psychedelics on creativity in an open-label natural setting

CONCLUSION

The aim of this study was to explore the effects of microdosing psychedelics on creative problem-solving. We observed an increase in divergent idea generation on the AUT, as evidenced by a significant increase in fluency, flexibility, and originality scores, as well as an increase in convergent thinking on the PCT after intake of a microdose of magic truffles. Given that scores of fluid intelligence did not change between the two measurement time-points, while we did observe change in scores in the creativity domain, it is possible that microdosing targets creativity performance, but not more general analytic cognition. These findings are in line with earlier studies finding positive effects of high doses of psychedelics on creative performance. In particular, the increase in originality scores on the AUT parallels the increase in originality scores after intake of Ayahuasca reported by. Taken together, our results suggest that consuming a microdose of truffles allowed participants to create more out-of-the-box alternative solutions for a problem, thus providing preliminary support for the assumption that microdosing improves divergent thinking. Moreover, we also observed an improvement of convergent thinking, that is, increased performance on a task that requires the convergence on one single correct or best solution. Before continuing to interpret our findings, it is important to consider the implications of the fact that we did not use a control group (for obvious ethical and practical reasons). Given the absence of a control group, we cannot rule out the possibility that changes from the first to the second time-point of measurement are due to the impact of other factors than the microdosed truffles. Two of these factors come to mind. For one, it is possible that increased performance from the first to the second time-point of measurement reflects learning. We consider that possibility not very likely, for three reasons. First, it does not seem to fit with the absence of an improvement for the intelligence measure, even though the Raven task shares many aspects with the PCT and the AUT. Second,) had participants perform the Remote Association Task, which can be considered a verbal version of the PCT, three times in different conditions and found neither condition effects nor, and this would be the learning-sensitive test, any interaction between condition and condition order. Third, a recent training study did not reveal any (positive) training effects on AUT performance. No effect of eight training sessions was observed for originality; a negative training effect was obtained for fluency, and a quadratic effect for flexibility. Both fluency and flexibility measures in fact decreased over the first three to four sessions, and only the flexibility measure eventually reached the original baseline in the 8th session. Taken together, we see no empirical support for the possibility that our observations might reflect a learning effect. For another, it is possible that increased performance from the first to the second time-point reflects an effect of expectation. Expectation effects are widely studied but not well understood. Drug-related expectation effects commonly require previous experience with the psychological effects of the respective drug, and it is likely that expectations operate by having been associated with and thus conditioned to stimuli and expectations preceding the actual effect. If so, the existence of expectation-based effects does not contradict the existence of real drug effects, as the former in fact rely on the previous experience of the latter. From that perspective, expectationbased effects and drug-induced effects are likely to have comparable impact on psychological functions, presumably even through the same physiological means. Accordingly, while we cannot definitely exclude that the effects we observed actually required the present intake of the drug, they even in the worst case are likely to rely on the previous intake and likely to reflect the effects of that previous intake. Notwithstanding these caveats, the outcome pattern of the present study is consistent with the idea that microdosing psychedelic substances improves both divergent and convergent thinking. The fact that intelligence was not improved suggests that this effect was rather selective, but the possibility remains that the Raven was less sensitive to the intervention than the other measures were. It is tempting to interpret our observations on divergent thinking in the context of recent suggestions that behavior drawing on flexibility and novelty benefits from a reduction of cognitive topdown control. According to this view, creativity tasks can be assumed to draw on two distinct, presumably opposing cognitive processes: flexibility is characterized by broadening the attentional scope, which enables individuals to generate many divergent ideas, while persistence is associated with a narrower attentional scope, thus allowing individuals to focus on one creative idea at a time. Some of the previous empirical dissociations of persistence and flexibility were related to dopaminergic functioning, such as in behavioral genetic studies demonstrating that polymorphisms supporting efficient dopaminergic functioning in the frontal cortex promote persistence while polymorphisms supporting striatal dopaminergic functioning promote flexibility (e.g.,; for an overview, see. This strengthens the view that frontal and striatal dopaminergic pathways are involved in persistence and flexibility. If we assume that convergent thinking relies more on frontal persistence while divergent thinking relies more on striatal flexibility, our outcomes raise the question how an intervention can manage to improve both convergent and divergent thinking. Classical hallucinogens, including psilocybin, belong to a group of tryptamines that are thought to exert their primary psychedelic effects through activity at the serotonergic 5-HT 2A receptor. Of particular interest in this regard are findings from animal studies showing that 5-HT 2A agonist activity (Halberstadt 2015) correlates with an increase in associative learningand improvements in the ability to adapt behavior more flexibly. Moreover, studies in humans have shown that the administration of psychedelics is associated with an increase in the personality trait) and that psychedelics can induce a reduction in symptoms associated with rigid behavior and thought patterns observed in obsessive-compulsive disorder) and depression. Such findings could be tentatively interpreted to imply that psilocybin facilitates more flexible, less constrained kinds of cognition. The 5-HT 2A receptors are widely distributed in in the brain and especially so in high-level prefrontal and associative cortex-regions important for learning and memory retrieval, this is likely to have important functional implications. For instance, postsynaptic 5-HT 2A receptor activation was shown to be associated with improvements in certain aspects of cognitionas well as an extinction of previously learned response patterns). However, it is important to note that function of the 5-HT system remains Belusive^given the inherent complexity of the serotonin system and more research has to be conducted in this regard to determine its function. While the assumption of a link between the use of psychedelics and an unconstrained brain state fits with our findings on divergent thinking, it does not to be consistent with our observations on convergent thinking. Microdosing improved performance on the PCT, suggesting that it promotes convergent thinking. Note that this observation contrasts with previous findings by, who reported that Ayahuasca, also a 5-HT 2A agonist, impaired performance on convergent thinking tasks. We believe this discrepancy could be a result of the difference in relative dosage.investigated participants after the intake of large doses of Ayahuasca, which is hardly comparable to the microdoses used in the present study. Previous research has shown a relationship between 5-HT 2A receptor activity and goal-directed behavior likely due to indirect modulation of DA release. Dopaminerelated adaptive behavior follows an inverted U shape, suggesting that smaller doses, such as the microdoses ingested by the participants in our current study, are more likely to move participants towards the most efficient mid-zone of the performance function than higher doses do (see Akbari Chermahini and Hommel 2012, for an application of this rationale on the impact of dopaminergic manipulations on creativity). Indeed, based on self-reports, an online study bysuggests that microdosing could enhance motivation and focus, and reduce distractibility and procrastination-which seems consistent with our observation of improved convergent thinking. These considerations suggest that microdoses truffle, and perhaps 5-HT 2A agonist in general improve processes that are shared by convergent and divergent thinking-irrespective of the existing differences. Indeed, both convergent and divergent thinking tasks rely to some degree on persistence and topdown control and to some degree on unconstrained flexibility. While convergent thinking tasks emphasize persistence over flexibility, and divergent-thinking tasks emphasize flexibility over persistence, they both require participants to keep in mind particular search criteria, which they need to test against candidate items in memory (a skill that relies on persistence and top-down control), and to search through novel and often unfamiliar items considered for this test (a skill that relies on flexibility). The tasks thus present participants with a dilemma, which can only be solved by finding a reasonable balance between the antagonistic skills; that is, to be persistent and flexible at the same time, or at least in quick succession. Microdosing therefore might promote the speed or smoothness of switching between persistence and flexibility-an ability thatrefer to as Badaptivity.^Taken together, whereas large doses of psychedelics might induce an hyper-flexible mode of brain functioning, and possibly a breakdown of control, microdoses may be able to drive brain functioning towards an optimal, highly adaptive balance between persistence and flexibility.