Time-resolved neural and experience dynamics of medium- and high-dose DMT
Evan Lewis-Healey, Carla Pallavicini, Federico Cavanna, Tomas D’amelio, Laura Alethia de la Fuente, Debora Copa, Stephanie Müller, Nicolás Bruno, Enzo Tagliazucchi, Tristan A Bekinschtein
bioRxiv Preprint Server December 19, 2024 preprint DOI: 10.1101/2024.12.19.629418 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Repeated-measures dose-dependent study |
|---|---|
| Sample size | 19 |
| Population | Healthy adults |
| Intervention | DMT |
| Dose | 20mg or 40mg |
| Topics | DMT |
| Citations | 1 |
| Key points | Lempel-Ziv complexity was the least strongly associated neural marker of the psychedelic state, challenging the hypothesis that neural complexity robustly tracks subjective experience during DMT intoxication. |
Abstract
N,N-Dimethyltryptamine (DMT) is a fast-acting psychedelic drug that induces a radical reorganisation of conscious contents and brain dynamics. However, our understanding of how brain dynamics support psychedelic-induced conscious states remains unclear. We therefore present a repeated-measures dose-dependent study of the subjective and neural dynamics induced through DMT under naturalistic conditions. Nineteen participants received either a 20mg or 40mg dose of freebase DMT across two sessions in a blinded, counterbalanced order. Electroencephalography (EEG) data and time-resolved measures of subjective experience (Temporal Experience Tracing) were collected. Both doses of DMT induced rapid changes in experience dimensions, with the 40mg dose inducing more extreme visual hallucinations and emotionally intense experiences. Strikingly, lempel-ziv complexity, previously hailed as a robust phenomenological correlate within the psychedelic-state, was the least strongly associated neural marker. These findings suggest that the relationship between neural complexity and phenomenology in psychedelic states is less clear than originally hypothesised.