People affected by the psychedelic drink known as ayahuasca often experience vivid visual and aural hallucinations and also report feeling asleep. Now, a new study published in "Scientific Reports" has shown that the drug is altering patterns of the user's brain wake to create a mental state that researchers describe as "dreaming while awake".
Ajahua is a bitter tea made by the Brazilian lineage banisteriopsis caapi, colloquially known as the "spiritual lineage," used in shaman-led spiritual ceremonies among indigenous people in the Amazon Basin. Its primary active ingredient is dimethyltriptin (DMT). That is the secret to Ajahuaca's powerful psychedelic effects, which can also create feelings of elation and fear or a sense of reverence or psychological breakthrough. However, those mind-altering properties come at a cost. Attendees at ceremonies are often advised to bring a bucket, as nausea and vomiting (and sometimes diarrhea) are common reactions to tea.
The brain controls perception and communication throughout the body through chemical neurotransmitters. Each neurotransmitter attaches to areas corresponding to nerve cells known as receptors. LSD, for example, targets serotonin receptors in the brain. Ayahuasca contains a compound (bistrister) that binds to dopamine receptors in the brain. (That's why banistirine has the potential as a treatment for Parkinson's disease, which destroys dopamine receptors.)
Several previous brain imaging studies involving humans have shown that psychedelics disrupt normal brain activity and increase accidental firing of neurons in the visual cortex. For example, a 2012 study by David Nut and colleagues from the London Center for Psychedelic Research (Imperial College) in London scanned the brains of 30 subjects (all experienced psychedelic users) while under the influence of psycho-psychoaccine. The lab then compared these scans with scans made after subjects ingested a placebo with saline. Overall brain activity has fallen into the so-called "standard mode", a collection of highly interconnected neurons that are usually activated when the brain is at rest. Psilocybin disrupted that synchronization, which can cause dislocating aspects – often reported, disintegrating feelings of self or ego – of hallucinogenic drugs.
In 2016, Nut et al. published the results of the second fMRI study, this time with subjects affected by LSD, compared to placebo. Once again, there was less synchronization (overall brain activity) of neurons in standard mode. But the researchers also found that certain different regions of the brain that did not normally communicate with each other did so under the influence of LSD, especially the visual cortex. This may explain the vivid complex hallucinations experienced by acid drinkers. The effect seems to be separate from the effect of the spread of the ego, however; it is possible to experience one without the other.
Another study the following year in scientific reports found a sudden increase in the incidence of brain activity in subjects affected by psychedelic drugs. This is possible evidence of a heightened state of consciousness that is usually associated with psychedelics. And earlier this year, a team of Swiss researchers used an MRI scan to monitor the brain under the influence of acid. The results support the idea that hallucinogens cause a system breakdown that helps the brain track what information comes from the real world and which is generated by the brain itself.
As Ars Johnson Timer reported in February, "Instead of a general flooding of the cortex, they found that a limited number of specific regions had increased activity. to widespread changes in the cortex. "
The current paper is Imperial's latest CPR study. The study included 13 subjects equipped with EEG caps and electrodes to monitor their brain activity while given IV infusion of DMT. The team found that DMT caused a significant drop in alpha waves, a sign of alertness, along with a correspondingly short increase in theta brain waves, indicating a state of sleep.
In addition, while it has been shown that brain activity is reduced in subjects affected by psychocybin and LSD, Imperial College researchers found more chaotic brain activity in subjects while under the influence of DMT. This may be why ayahuasca users report more vivid visual effects and a greater sense of immersion than is usually experienced with other psychedelics.
"We saw an emerging rhythm that was present during the most intense part of the experience, which suggested that an order was emerging amidst otherwise chaotic patterns of brain activity," lead author Christopher Timerman said. "From the altered brainwaves and participants' reports, it is clear that these people are completely immersed in their experience – it's like dreaming just far more vivid and immersive, it's like dreaming, but with open eyes."
Future studies could include extending the time they spend on DMT to gather even more brainwave data, or submit participants to fMRI images while on DMT, as already done with psychocib and LSD.
"It is difficult to capture and communicate what it is to people experiencing DMT, but comparing it to dreaming while awakening or near death experience is useful," said CPD co-author and head Robin Kuhart-Harris. "It is our feeling that research with DMT can provide an important insight into the link between brain activity and consciousness, and this small study is the first step down the road."
DOI: Scientific Reports, 2019. 10.1038 / s41598-019-51974-4 (For DOI).