Title & Introduction

  • Paper Title: DMT-induced shifts in criticality correlate with ego-dissolution
  • Published In: bioRxiv (preprint)
  • Publish date: February 8, 2025
  • Authors: Mona Irrmischer, Marco Aqil, Lisa Luan, Tongyu Wang, Hessel Engelbregt, Robin Carhart-Harris, Klaus Linkenkaer-Hansen, Christopher Timmermann
  • Objective: To investigate the effects of DMT on brain oscillations and their relationship to subjective experiences, particularly ego-dissolution.
  • Importance: This study provides insight into how DMT alters brain dynamics by shifting neuronal oscillations away from criticality and toward subcritical states, correlating with ego-dissolution experiences. These findings help to clarify the neural mechanisms underlying psychedelic-induced changes in consciousness.

Summary & Takeaways

Key Takeaway: DMT shifts brain oscillations away from criticality, increasing entropy and reducing complexity, with these changes correlating with ego-dissolution.

Practical Application: Understanding how DMT modulates brain dynamics can help refine psychedelic therapies, particularly in treating disorders related to rigid cognitive patterns, such as depression and PTSD.

Key Background Information

  • Context: The brain operates near a "critical point" between order and disorder, which is associated with optimal information processing. Psychedelics, including DMT, are believed to alter brain dynamics by modulating this criticality.
  • Hypothesis: DMT shifts the brain away from criticality toward a subcritical state, increasing entropy and disrupting self-related processing.

Methodology

  • Study Design: Placebo-controlled, single-blind, within-participant EEG studies
  • Participants: 27 healthy adults (12 female, mean age 34.1)
  • Intervention/Exposure: Intravenous administration of DMT (7-20 mg) vs. placebo (saline)
  • Controls: Placebo-controlled within-participant design
  • Duration: EEG recordings taken at baseline and up to 20 minutes post-administration

Key Findings

Primary Outcomes:

  • DMT significantly decreased long-range temporal correlations (LRTC) in alpha, theta, and beta frequency bands, shifting brain dynamics away from criticality.
  • Functional Excitatory/Inhibitory (fE/I) ratio analysis indicated a shift towards a more entropic, subcritical regime.
  • EEG alterations in alpha and theta bands significantly correlated with self-reported ego-dissolution.

Secondary Outcomes:

  • Increased entropy and decreased complexity in neuronal oscillations.
  • Reduced DFA exponents in EEG signals, indicating a loss of structured, long-range temporal organization.
  • These shifts may reflect a disruption of the structured self-representation maintained in normal waking consciousness.

Interpretation & Implications

  • Conclusion: DMT shifts brain dynamics towards a subcritical regime, increasing entropy and reducing complexity, which correlates with ego-dissolution. This suggests that psychedelic experiences involve a fundamental reorganization of neural activity.
  • Implications: These findings provide a mechanistic explanation for how psychedelics alter self-perception and suggest potential therapeutic applications in conditions where rigid self-referential thinking plays a role, such as depression and PTSD.
  • Limitations: The study used EEG, which has limited spatial resolution, and was conducted in a controlled environment, which may not fully reflect real-world psychedelic experiences.

Researchers & Publication

  • Researchers: Mona Irrmischer, Marco Aqil, Lisa Luan, Tongyu Wang, Hessel Engelbregt, Robin Carhart-Harris, Klaus Linkenkaer-Hansen, Christopher Timmermann
  • Publication Name: bioRxiv (preprint)
  • Study URL: https://doi.org/10.1101/2025.02.08.636868
Share this post