Consciousness is one of the biggest scientific mysteries of our time. It’s something every human—and possibly many animal species—experiences, but the radically subjective nature of consciousness paired with the unfathomable complexity of the brain makes it exceedingly difficult for scientists to understand. To be sure, scientists and philosophers have proposed a staggering number of theories that purport to explain consciousness that range from mundane to magical. The French philosopher Henri Bergson, for instance, likened consciousness to a universal medium that humans tune in to like a radio receiver selecting a channel. The prevailing scientific view of consciousness, on the other hand, treats it as an emergent phenomenon generated by the interplay between tens of billions of neurons in the human brain.
If consciousness really is the result of our neural activity, we might expect to be able to see evidence of it by watching the way neurons interact using brain imaging technology. Psychedelics can prove remarkably useful in this respect since they have the ability to profoundly change the perceptions of those under their influence and open up new states of consciousness. By comparing the subjective experience reported by someone on psychedelics with images of their tripping brain, scientists can begin to explore how the brain generates consciousness in our day-to-day lives.
Using psychedelics and brain imaging technology to explore consciousness is a well-worn path in the psychedelic research community. Scientists have used brain imaging technology to study human noggins on substances as diverse as LSD, psilocybin and salvia. But until recently, the widely acknowledged “king of psychedelics,” N-N-dimethyltryptamine or N-N-DMT, was not included among them. New research published last November in Scientific Reports is the first to show the brain tripping on DMT and opens a promising new pathway toward the scientific understanding of consciousness.
A team of researchers based at Imperial College London intravenously administered DMT to 13 subjects and then monitored their brains using an electroencephalogram or EEG, which records the electrical activity in brain cells. The researchers then compared this electrical activity to the subjective experiences reported by the subjects to map changes in brain activity to changes in consciousness.
According to the researchers, DMT was an attractive choice to study alternative states of consciousness due to its rapid onset and “unusually vivid imagery and somatic effects, which arise within seconds of the injection.” People who have taken DMT, which is typically smoked but in this case administered intravenously, often report a feeling of blasting off into an alternate reality that feels every bit as real as our own. A DMT trip usually only lasts a few minutes, but during this time users have little to no contact with the real world. Upon returning from a DMT trip, users often report receiving profound insights, and it is not uncommon to hear of meeting sentient beings in this other world. (Renowned psychonaut Terence McKenna famously likened these entities to “machine elves.”)
The researchers found that their tripping subjects had a large decrease in the power of their brain’s alpha and beta waves. Beta waves are linked with focused mental activities, like reading this article or solving a puzzle, whereas alpha waves are linked to the state of a brain at rest such as during meditation. The decrease in the power of alpha brain waves is consistent with previous research, which noted decreases in alpha waves in subjects on LSD and ayahuasca. This makes sense, given that alpha waves are connected to high-level psychological functions, which are disrupted during a trip.
Still more interesting was that the researchers registered an uptick in delta and theta brain waves during the peak of the DMT experience. These types of brain waves are perhaps most well known for their association with REM sleep—the deep sleep where dreaming occurs. This may not be totally surprising, given that both dreams and DMT immerse people in a radically different reality.
Finally, the researchers found an increase in “spontaneous signal diversity,” which means that the brain was making a lot of connections that it normally wouldn’t make without DMT. This is also a hallmark of other psychedelic substances. The researchers found that the diversity of the brain signals increased as the experience grew more intense for their subjects.
While scientists are still just beginning to understand these substances, they hold immense promise for the treatment of various mental disorders. Indeed, the researchers suggest that the results of their DMT study highlight the “antidepressant potential of DMT and DMT-related compounds.” There is still a lot of work to be done, but this research represents a big advance in our understanding of consciousness, both in normal waking life and under the influence of psychedelic substances. Whereas the first generation of psychedelic researchers in the 1960s could only rely on the subjective reports of individuals while they were tripping, modern brain imaging technology has allowed researchers to link these subjective experiences with what is actually happening in their heads.
“The present study’s findings significantly advance our understanding of the brain basis of one of the most unusual and intense altered states of consciousness known—previously likened to dreaming and the near death experience,” the researchers concluded. “By observing what is lost and gained when consciousness transitions in extreme ways, psychedelic neuroscience promises to enrich our knowledge and appreciation of mind-brain relationships in the broadest range of contexts, while inspiring as yet untold applications.”