Research library / Brain imaging study
Time-resolved Neural and Experience Dynamics of Medium- and High-dose N,N-Dimethyltryptamine (DMT)
Lewis-Healey E, Pallavicini C, Cavanna F, et al. Journal of Cognitive Neuroscience 2026;38(6):1244-1263
This study recorded brain activity with EEG while 19 people took freebase DMT at two doses, 20 mg and 40 mg, in separate sessions, without knowing which dose came first. Participants also continuously traced how their experience changed over time. Both doses shifted experience within moments, and the higher dose brought stronger visual effects and more emotional intensity. When the researchers matched brain signals against these experience reports, alpha-wave power and a measure called permutation entropy tracked the experience best. A widely cited brain "complexity" measure linked to psychedelic states did worst. The study is small and has no placebo session, so it says more about how to measure the DMT state than about benefits or risks. Its main message is that the link between brain complexity and psychedelic experience is weaker than assumed.
What it found
- Both doses changed experience rapidly; 40 mg produced more extreme visual hallucinations and more emotionally intense experiences
- Alpha-band oscillatory power and permutation entropy were the EEG features most closely tied to moment-to-moment experience
- Lempel-Ziv complexity, often cited as a marker of the psychedelic state, showed the weakest link to experience