DMT alters cortical travelling waves.
Andrea Alamia, Christopher Timmermann, David Nutt, Rufin Vanrullen, Robin Carhart-Harris
Elife October 12, 2020 DOI: 10.7554/elife.59784 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Placebo-controlled crossover trial Peer reviewed |
|---|---|
| Population | Participants receiving DMT and placebo (saline) with eyes closed |
| Intervention | N |
| Topics | DMT |
| Keywords | Psychedelics: DMT Psychedelic experiences Electrical activity Cortical travelling waves Consciousness: conscious experience Perception Brain's dynamic nature |
| Citations | 86 |
| Key findings | DMT reduced top-down alpha rhythms and increased bottom-up forward cortical travelling waves, supporting a model where psychedelics reduce the precision-weighting of priors. |
Abstract
Psychedelic drugs are potent modulators of conscious states and therefore powerful tools for investigating their neurobiology. N,N, Dimethyltryptamine (DMT) can rapidly induce an extremely immersive state of consciousness characterized by vivid and elaborate visual imagery. Here, we investigated the electrophysiological correlates of the DMT-induced altered state from a pool of participants receiving DMT and (separately) placebo (saline) while instructed to keep their eyes closed. Consistent with our hypotheses, results revealed a spatio-temporal pattern of cortical activation (i.e. travelling waves) similar to that elicited by visual stimulation. Moreover, the typical top-down alpha-band rhythms of closed-eyes rest were significantly decreased, while the bottom-up forward wave was significantly increased. These results support a recent model proposing that psychedelics reduce the 'precision-weighting of priors', thus altering the balance of top-down versus bottom-up information passing. The robust hypothesis-confirming nature of these findings imply the discovery of an important mechanistic principle underpinning psychedelic-induced altered states.