The Default Mode Network (DMN) is by now a familiar name in popular psychedelic circles. It’s a collection of brain areas that talk loudly to each other when we’re not doing any focussed tasks – basically when we’re daydreaming, thinking about ourselves, or conceptualising the past or future.
We know two important things about the DMN: it’s overactive in depression, and psychedelics can help to reset it. Studies have shown that classic psychedelics LSD and psilocybin can dramatically reduce the chatter of the DMN during a psychedelic experience, and allow it to re-form itself into a more stable network afterwards – correlating with decreased depressive symptoms.
Salvinorin A, the main psychedelic component of Salvia divinorum, is not at all like these classic psychedelics. While LSD and psilocybin mainly activate 5-HT2A receptors in the brain, and produce highly visual and often introspective psychedelic experiences; Salvinorin A has barely any 5-HT2A activity, instead activating kappa-opioid receptors and sending users on bizarre and often horrifying trips.
I’ve written (and spoken) fairly extensively about the weirdness of Salvia, and what it means for consciousness. Salvia disrupts an area of the brain called the claustrum, and this is correlated with an almost complete dismantling of typical conscious experience. Our usually coherent and coordinated stream of sensory perceptions, understanding of selfhood, and grasp of the concept of time, dissolves into a barely comprehensible array of pure sensation. Existence is literally ripped apart, in a very fundamental and powerful way, which is not seen as often in classic psychedelics.
Now, new research has shown that Salvinorin A is also connected to the DMN. Twelve experienced psychonauts were given doses of Salvinorin A while in an MRI machine, which showed that the unique psychedelic reduced the connectivity of the DMN in a very similar way to LSD and psilocybin.
This is very preliminary data and there are a number of potential issues with the sample of participants. But it’s the first time we’ve seen brain scans of people under the influence of Salvinorin A, and it shows us that the dampening-down of the DMN may be a pretty universal feature of psychedelic substances.
With this interesting finding comes the usual neuromemery we’ve come to expect from physicalist scientists: The authors of the research paper subtly suggest that reductions in DMN connectivity are causing antidepressant effects, rather than simply being correlated with them.
The importance of this distinction becomes especially clear with Salvia. We know, from decades of research and countless testimonies, that the Salvia experience is profoundly different in quality from typical psychedelics. While Salvinorin A may well be associated with a similar reduction in DMN activity as LSD, it would be a mistake to think the two psychedelics could be approached in the same way by a psychedelic therapist.
We need to avoid a future where psychedelic therapists work through an MRI machine, spewing keywords at a patient while watching the DMN parameters creep towards acceptable levels of disconnection. Instead, psychedelic therapy needs to take the subjective experience of the patient as the primary source of information.
Thanks to this research, we have more evidence that there is a very basic and quite consistent neural correlate with ego dissolution and the mystical experience. But the activity of the DMN doesn’t tell us anything about the quality of psychedelic experiences, or which therapeutic approaches are most likely to bring about healing in an individual patient with a unique substance.
Full paper: Doss, M.K., May, D.G., Johnson, M.W. et al. The Acute Effects of the Atypical Dissociative Hallucinogen Salvinorin A on Functional Connectivity in the Human Brain. Sci Rep 10, 16392 (2020). https://doi.org/10.1038/s41598-020-73216-8