Mindfulness and Psychedelics: A Combined Neurophenomenological and Pharmacological Approach to the Characterization of Mindfulness States in Experienced Meditators

The investigators are doing this project to investigate potential neurophysiological synergy effects between mindfulness meditation and psychedelics. Previous studies have found that both mindfulness and psychedelics like psilocybin modulate neural activity and connectivity of the same brain network. However, little is known about the potential interactions between mindfulness meditation and psychedelics. The indigenous plant preparation "Ayahuasca" is particularly interesting for the combination with mindfulness meditation. It contains two components, N,N-dimethyltryptamine (DMT) and harmine, which are very similar to the body's own messenger substance serotonin and increase its effect in the body. The investigators would now like to find out how these corresponding networks change in experienced meditators after DMT/Harmine-enhanced mindfulness meditation and how this affects their subjective experience. For this functional MRI imaging will be performed, as well as psychometric assessments and detailed experiential interviews before and after a three-day meditation retreat. Participants will be randomly assigned to one of two groups. One group receives DMT and harmine during the sitting meditation on the second day, the other group receives a corresponding placebo. Neither the participants nor the investigator know who will receive a placebo or the combination of DMT/harmine on the day of the experiment. The pre- and post-measurements of the MRI imaging and psychometric questionnaires of the DMT/Harmine group are compared with those of the placebo control group. By examining the synergistic effects of mindfulness meditation and DMT/harmine, the aim of this study is to contribute to a comprehensive understanding of the neurophenomenology of rare and inaccessible phenomena of consciousness.