Trips and neurotransmitters: Discovering principled patterns across 6850 hallucinogenic experiences.

Psychedelics likely alter consciousness by disrupting the usual hierarchy between higher-level association cortex and incoming sensory signals. Analyzing 6,850 free-form testimonials about 27 drugs alongside 40 neurotransmitter receptor subtypes and their gene expression maps in the brain, the authors found that drug-induced changes in awareness correspond to cortex-wide distributions of receptor density. Each receptor-experience factor spanned a continuum from higher-level association to sensory input, possibly reflecting a collapse of hierarchical order among large-scale brain networks. The framework reveals the semantic structure underlying diverse drug experiences and links it directly to brain anatomy.

Study at a glance

Abstract

Psychedelics probably alter states of consciousness by disrupting how the higher association cortex governs bottom-up sensory signals. Individual hallucinogenic drugs are usually studied in participants in controlled laboratory settings. Here, we have explored word usage in 6850 free-form testimonials about 27 drugs through the prism of 40 neurotransmitter receptor subtypes, which were then mapped to three-dimensional coordinates in the brain via their gene transcription levels from invasive tissue probes. Despite high interindividual variability, our pattern-learning approach delineated how drug-induced changes of conscious awareness are linked to cortex-wide anatomical distributions of receptor density proxies. Each discovered receptor-experience factor spanned between a higher-level association pole and a sensory input pole, which may relate to the previously reported collapse of hierarchical order among large-scale networks. Coanalyzing many psychoactive molecules and thousands of natural language descriptions of drug experiences, our analytical framework finds the underlying semantic structure and maps it directly to the brain.