Human brain effects of DMT assessed via EEG-fMRI.
Christopher TimmermannLeor RosemanSharad HaridasFernando E RosasLisa LuanHannes KettnerJonny MartellDavid ErritzøeEnzo TagliazucchiCarla PallaviciniManesh GirnAndrea AlamiaRobert LeechDavid J NuttRobin L Carhart-HarrisPublished in: Proceedings of the National Academy of Sciences of the United States of America (2023)
Psychedelics have attracted medical interest, but their effects on human brain function are incompletely understood. In a comprehensive, within-subjects, placebo-controlled design, we acquired multimodal neuroimaging [i.e., EEG-fMRI (electroencephalography-functional MRI)] data to assess the effects of intravenous (IV) N,N-Dimethyltryptamine (DMT) on brain function in 20 healthy volunteers. Simultaneous EEG-fMRI was acquired prior to, during, and after a bolus IV administration of 20 mg DMT, and, separately, placebo. At dosages consistent with the present study, DMT, a serotonin 2A receptor (5-HT2AR) agonist, induces a deeply immersive and radically altered state of consciousness. DMT is thus a useful research tool for probing the neural correlates of conscious experience. Here, fMRI results revealed robust increases in global functional connectivity (GFC), network disintegration and desegregation, and a compression of the principal cortical gradient under DMT. GFC × subjective intensity maps correlated with independent positron emission tomography (PET)-derived 5-HT2AR maps, and both overlapped with meta-analytical data implying human-specific psychological functions. Changes in major EEG-measured neurophysiological properties correlated with specific changes in various fMRI metrics, enriching our understanding of the neural basis of DMT's effects. The present findings advance on previous work by confirming a predominant action of DMT-and likely other 5-HT2AR agonist psychedelics-on the brain's transmodal association pole, i.e., the neurodevelopmentally and evolutionarily recent cortex that is associated with species-specific psychological advancements, and high expression of 5-HT2A receptors.
Keyphrases
- resting state
- functional connectivity
- positron emission tomography
- computed tomography
- healthcare
- magnetic resonance imaging
- endothelial cells
- big data
- poor prognosis
- electronic health record
- physical activity
- magnetic resonance
- low dose
- squamous cell carcinoma
- randomized controlled trial
- radiation therapy
- machine learning
- sleep quality
- chronic pain
- double blind
- working memory
- contrast enhanced
- brain injury
- single molecule
- blood brain barrier
- rectal cancer
- diffusion weighted imaging