The first brain scans of people on LSD have revealed that the drug causes different regions of the brain to become more entangled and connected. This, researchers think, may contribute to the experience of losing oneself that many drug users report — a phenomenon generally referred to as "ego-dissolution."
The report, published today in Current Biology, is a first for the field of neuroscience, and it also signals what will most likely be a new wave of basic LSD research. The study describes the brain activity of 15 people who got their brains scanned while on LSD. The researchers found that the drug increased the connection between two regions of the brain: one that deals with how people perceive themselves and one that deals with how people perceive the environment. The finding is the second in a set of studies published by the same group of scientists this week. On Monday, they announced that when people take LSD, the brain becomes a lot more active, which could explain why some users experience hallucinations. But today's study goes deeper into those findings, and probes the nature of human consciousness.
LSD research was essentially banned in the '70s
The history of LSD research is fragmented and somewhat controversial. In the 1950s and '60s, scientists investigated the drug as a treatment for mental illness, as well as for basic neuroscience purposes. But in the '70s, those studies essentially ended. The Controlled Substances Act of 1970 declared that LSD and other psychoactive drugs had "no currently accepted medical use" in the US. It also reclassified LSD as a Schedule 1 drug, a restriction that caused its production and its transport to be very tightly controlled. As a result, it became nearly impossible for American researchers to investigate the drug for treatment purposes. Abroad, similar bans also halted its study. Now, some research groups are starting to take up the work again. Two years ago, for instance, scientists used LSD to curb cancer patients' anxiety about death. Still, no one had ever used fMRI technology to look at the drug's effect on the brain. That's why today's study is so novel.
"In comparison to other drugs such as cocaine or heroine, psychedelics are not a huge business; one could foresee legalization without running into deep problems with politics and drug lords," says Enzo Tagliazucchi, a neuroscientist at the German University of Kiel who co-authored the study. "This has led many researchers to push the governments to authorize human research with psychedelics. The hope here is that these drugs can be used to treat disorders such as depression and anxiety."
In the study, Tagliazucchi and his team gave LSD to 15 people who had previous experience with psychedelics, and scanned their brains in an fMRI machine. Then, they compared the results to scans from the same participants after they took a placebo. The scientists also asked the study participants about their experience under LSD.
a "shift of consciousness from the self towards the surrounding universe."
The researchers found that LSD triggered an increase in global connectivity in the fronto-parietal cortex, a region of the brain that's associated with how we perceive ourselves. They also found that this region became more entangled with the part of the brain that deals with how we perceive our environment. Because of this, Tagliazucchi and his team think the over-connectedness seen in the brain contributes to the phenomenon ego-dissolution. It's "shift of consciousness from the self towards the surrounding universe," Tagliazucchi says.
The study has some limitations. For one thing, all the participants were experienced drug users. That means that although they are probably better at assessing their experience compared with people who've never taken similar drugs, their knowledge of the drug's typical effects could bias some of the results, Tagliazucchi says. Second, the machine that the researchers used to scan the participants' brains is very sensitive to people's movements. Because of this, the squirmier subjects who were initially enrolled in the study had to be yanked. Because of the small number of people who made it into the study, the researchers' conclusions are less solid than they would like. Finally, because the researchers don't know a lot about ego-dissolution, they were limited in their ability to ask questions, Tagliazucchi says. "If we knew more about this experience, we could have asked more detailed questions and perform a detailed analysis."
These limitations mean that the study should really be seen as a starting point. With more work in this area, scientists might gain a better understanding of the way in which humans perceive the world and construct reality. "Consciousness is everything we've got; everything we perceive, feel, and 'what it's like' to be ourselves is mediated by our consciousness," Tagliazucchi says. "Since we've all got one, and it's so important, it is reasonable that we try to find out how it works. Our article goes in that direction."