Abstract

The practice of microdosing with psychedelics is becoming increasingly popular, yet the purported benefits of this practice are not conclusively supported by the available evidence. Studies of microdosing without a placebo condition are vulnerable to expectation effects, while carefully designed laboratory studies might not provide a sufficiently engaging setting for the participants. To simultaneously circumvent these two limitations, we investigated the effects of a self-blinded dose (placebo or 500 mg of dried mushroom material) consumed under natural conditions. Our study included over thirty participants and assessed behavior (actigraphy and sleeping patterns), cognition (conscious perception [binocular rivalry, backward masking, local-global auditory paradigmn], attention, inhibitory control), physiology (heart rate, resting state EEG and task-evoked response potentials), and convergent/divergent thinking. Our preliminary results suggest a widespread effect of microdosing across these domains, reflected in objective measurements such as EEG and physiological time series. In conclusion, we investigated the effects of microdosing over multiple domains under natural conditions while controlling for expectation effects following a self-blinding paradigm, a unique hybrid design especially suited for studies where the motivation and engagement of the participants plays a crucial role.