This pre-print repeated-measures dose-dependent study (n=19) investigates DMT’s subjective and neural dynamics under naturalistic conditions. Participants received 20mg or 40mg doses of freebase DMT in a blinded, counterbalanced design, with EEG data and time-resolved subjective measures collected. The 40mg dose produced more intense visual hallucinations and emotional responses. Neural analyses revealed alpha power and permutation entropy were most associated with subjective experiences, whereas lempel-ziv complexity was less predictive, challenging prior assumptions about its role in psychedelic states.
Abstract of Time-resolved neural and experience dynamics of medium- and high-dose DMT
“N,N-Dimethyltryptamine (DMT) is a potent and fast-acting psychedelic drug that induces a radical reorganisation of the contents of consciousness, comprising the dissolution of time and space and perceptual immersion into an ‘alternate reality’. While contemporary research has somewhat advanced our understanding of DMT, and psychedelics more broadly, there is little research that integrates time-resolved measures of subjective experience with temporally fine-grained brain imaging. We therefore present the current study, 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 dosing sessions in a blinded, counterbalanced order, with blinding rates consistent across doses. Electroencephalography (EEG) data was collected, as well as time-resolved retrospective measures of subjective experience (Temporal Experience Tracing). Both doses of DMT induced rapid changes in experience dimensions. However, the 40mg dose induced significantly more extreme visual hallucinations and emotionally intense experiences. Further, we computed a variety of neural markers on the EEG data, and found that oscillatory alpha power and permutation entropy were most strongly associated with continuous subjective experience dimensions. Strikingly, lempel-ziv complexity, a previously hailed as a robust correlate of subjective experiences within the psychedelic-state, was the least strongly associated neural marker. These findings provide an important insight into how distinct neural dynamics may contribute to this radical and intense altered state of consciousness.”
Authors: Evan Lewis-Healey, Carla Pallavicini, Federico Cavanna, Tomas D’Amelio, Laura Alethia De La Fuente, Debora Copa, Stephanie Müller, Nicolas Bruno, Enzo Tagliazucchi, Tristan Bekinschtein
Summary of Time-resolved neural and experience dynamics of medium- and high-dose DMT
Psychedelic compounds are increasingly being used as tools to study consciousness due to their ability to induce profound alterations in perception, thought, and self-awareness. Among serotonergic psychedelics, DMT stands out for its rapid onset and brief but intense effects, often involving distortions in time and space as well as immersive visual and auditory hallucinations. DMT is unique in its ability to induce highly immersive states described as “breakthrough” experiences, wherein users may report encountering autonomous entities and intricate visual patterns.
Previous studies have associated these altered states with specific neural changes, including reductions in alpha brainwave activity and increased neural connectivity. Entropic Brain Theory suggests that psychedelics induce states of high neural entropy, correlating with phenomenologically rich experiences. However, prior methods for measuring these experiences have relied on static or simplified self-reports, which fail to capture the dynamic and evolving nature of subjective psychedelic states.
The current study aims to address these gaps by combining advanced brain imaging techniques with time-sensitive measures of subjective experience. Using a method called Temporal Experience Tracing (TET), the study investigates how different doses of DMT influence neural and experiential dynamics over time. This approach allows for a more granular mapping of the relationship between brain activity and subjective experience during altered states of consciousness.
Methods
Study Design
Find this paper
Time-resolved neural and experience dynamics of medium- and high-dose DMT
https://doi.org/10.1101/2024.12.19.629418
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Cite this paper (APA)
Lewis-Healey, E., Pallavicini, C., Cavanna, F., D'Amelio, T., De La Fuente, L. A., Copa, D., ... & Bekinschtein, T. (2024). Time-resolved neural and experience dynamics of medium-and high-dose DMT. bioRxiv, 2024-12.
Study details
Topics studied
Healthy Subjects
Neuroscience
Study characteristics
Original
Placebo-Controlled
Double-Blind
Within-Subject
Participants
19
Humans
Compound Details
The psychedelics given at which dose and how many times
DMT 20 - 40mg | 2x
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