People under the influence of psychedelic beer, known as ayahuasca, often experience vivid visual and auditory hallucinations and also report feeling as if they were in a dream. Now, a new study published in Scientific Reports has shown that the drug alters the user's brainwave patterns to create a mental state that researchers describe as "dreaming while awake."
Ayahuasca is a bitter tea prepared from the Brazilian vine banisteriopsis caapi colloquially known as the "spirit vine" used in spiritual ceremonies led by a shaman among locals in the Amazon. Its main active ingredient is dimethyltryptamine (DMT). This is the secret of the powerful psychedelic effects of ayahuasca, which can also produce a sense of rapture and fear or a sense of epiphany or psychological breakthrough. However, these mind-altering properties come at a cost. Often participants in ceremonies are encouraged to carry a bucket, as nausea and vomiting (and sometimes diarrhea) are common reactions to tea.
The brain controls the perception and communication in the body through chemical neurotransmitters. Each neurotransmitter attaches to matching areas of nerve cells known as receptors. LSD, for example, targets brain serotonin receptors. Ayahuasca contains a compound (banisterine) that adheres to the dopamine receptors in the brain. (That is why banisterine has the potential to cure Parkinson's disease, which destroys dopamine receptors.)
Several previous studies of brain imaging involving humans have shown that psychedelics disrupt normal brain activity and enhance the accidental firing of neurons into the visual cortex. For example, a 2012 study by David Knut and his colleagues at Imperial College's (CPR) London Center for Psychedelic Research (CPR) scans the brains of 30 subjects (all experienced psychedelic users) while under the influence of psilocybin – known as magic mushrooms. The lab then compared these scans with those made after the subjects had swallowed the placebo with salt water. Overall brain activity falls into the so-called "default mode" – a collection of highly interconnected neural networks that usually shoot together when the brain is at rest. Psilocybin interrupted this synchronization, which can cause dissociative aspects – often a communicative, decaying sense of self or ego – of hallucinogenic drugs.
In 2016, Nutt et al. . published the results of a second fMRI study, this time with LSD subjects, compared with placebo. Again, there was less synchronization (total brain activity) between neurons in the default mode. But researchers have also found that certain distinct areas of the brain that don't normally communicate with one another make it under the influence of LSD, especially the visual cortex. This could explain the life-threatening hallucinations experienced by people trying to deal with acid. The effect seems to be separate from that of dissolving the ego; it is possible to try one without the other.
Another study the following year in Scientific Reports found a sudden increase in chance in brain activity in subjects under the influence of psychedelic drugs. This is possible evidence of a heightened state of consciousness, usually associated with psychedelics. Earlier this year, a team of Swiss researchers used MRI imaging to monitor the brain under the influence of acid. The results support the notion that hallucinogens cause the system to break down, which helps the brain track what information comes from the real world and what is generated by the brain itself.
As John Timer of Ars reported in February, "Instead of general bark flooding, they found that a limited number of specific regions have increased activity. This suggests that hallucinogen-induced conditions differ from conditions such as anesthesia and sleep. leading to widespread changes in the bark. " This document is the latest CPR study by Imperial. The study included 13 individuals equipped with EEG caps and electrodes to monitor their brain activity while being administered an IV infusion of DMT. The team found that DMT was causing a noticeable decrease in alpha waves, a wake-up sign, along with a corresponding brief increase in theta brain waves, indicative of a sleep state.
Additionally, while brain activity showed a decrease in subjects under the influence of psilocybin and LSD, researchers at Imperial College found more chaotic brain activity in subjects while under the influence of DMT. This may be why ayahuasca users report brighter visual effects and a greater sense of immersion than is commonly encountered with other psychedelics.
"We saw a rhythm that was present during the most intense part of the experience, suggesting an emergent order against the otherwise chaotic patterns of brain activity," said lead author Christopher Timmerman. clearly these people are completely immersed in their experience – it's like dreaming only far more vivid and immersive, like dreaming, but with eyes open. "
Future research may include extending the time subjects spend on DMT to collect more data about brainwave or subjecting fMRI participants while on DMT, as has already been done with psilocybin and LSD.
"It's hard to capture and report what it is to people who have DMT, but to resemble it dream while you are awake or near-death is rewarding, ”said CPR co-author and head Robin Carhart-Harris. "Our point is that DMT research can provide an important picture of the link between brain activity and consciousness, and this small study is the first step along the way."
DOI: Scientific Reports, 2019. 10.1038 / s41598-019- 51974 -4 (For DOI).