Psychedelics (from the Greek psyche: mind, delos: reveal), believed to be the oldest class of psychopharmacological agents in recorded history, are potent psychoactive substances known for their ability to induce a heightened state of consciousness in users. Over the years, controversy surrounding their effects has made investigations into the science of psychedelics difficult, however scientists have been regaining an interest in their action within the brain and the implications.
On Saturday 22nd September, Chris Timmermann - a neuroscience PhD candidate from Imperial College London (ICL) - delivered a fascinating presentation at the New Scientist Live festival in London on the use of psychedelics to study consciousness. Over at the Humans stage, Timmermann set the scene by exploring the longstanding use of classic psychedelics (ayahuasca, magic mushrooms, San Pedro and peyote) by individuals in Africa, America and Siberia for medicinal and ceremonial purposes. “Experiences occur below the threshold of consciousness” explained Timmerman, therefore when we take psychedelics we “call upon our consciousness”, which usually results in a feeling of “deep immersion with reality or a different dimension”. Hallucinations, bodily effects and the perception of unworldly entities are other commonly reported effects. Despite centuries of literature documenting psychedelic experiences, our understanding of what is happening in the human brain, at a fundamental level, has been less apparent. Until now.
N, N-Dimethyltryptamine, better known as DMT, is found in ayahuasca and is believed to be the most potent psychedelic compound, creating “an axis to a different dimension” explained Timmermann. To better understand its effects on the brain, his colleagues at ICL have been investigating the effects of intravenous injections in 13 human volunteers under controlled conditions in their lab. During the single-blind placebo-controlled study all participants received the placebo on day one followed by DMT on day two. Crucially, to eliminate subject bias, they were not told which drug they would receive before each session.
Timmermann showed drawings produced after the experiments by those who had received DMT depicting complex, vibrant scenes that had been described by participants as a “world analog” or “dreamworld”. Additionally, a significant overlap was found between the DMT-induced experience and near-death experiences (NDEs). Most participants recall the presence of other beings, out of body experiences and an ego-dissolution, all of which are commonly reported in NDEs. Interestingly, Timmermann added that participants with certain personality traits such as neuroticism or strong religious and/or mystical beliefs were more likely to recall these NDE-like experiences. He went on to suggest that contextual factors such as personality or a propensity towards delusionary thinking can greatly influence the quality and intensity of DMT-induced NDE-like experiences.
Although one can argue that knowledge of these psychological effects is not new, the information that electroencephalography (EEG) recordings revealed to Timmerman and his team, just might be.
How does DMT affect brain activity?
EEG is a non-invasive approach involving the positioning of electrodes on the scalp to measure and record the electrical activity that is generated from neuronal communication in the brain. Neuroscientists investigating consciousness typically use EEGs to study these brainwaves during altered states of consciousness as they provide insights into changes in brain activity.
Our conscious active brain, is dominated by highly active beta and gamma waves. When we are relaxed - but not asleep - alpha waves predominate. As we become drowsy and fall asleep theta and delta waves become more active (notably, these brain waves are associated with dreaming).
The different frequencies of recordable human brain waves . Credit: M. Roohi-Azizi, et al., 2017.
Broadly speaking, Timmermann and his team discovered that all rhythms were dampened during the DMT-induced psychedelic experience. This effect was however, more noticeable for alpha wave activity. Since activation of alpha waves is thought to represent “active disengagement from the environment”, their dampening during a DMT trip was used to support the claims made by participants that they were significantly more engaged with the environment on DMT. Timmermann suggests that increased disorganization within the brain, may be responsible for this detachment from the self and the resulting “unity” with the world. Furthermore, having asked the volunteers to monitor the intensity of their experience throughout the experiment, the researchers found a significant correlation between increased activation of delta and gamma waves and periods of the highest intensity. Similar to what occurs in the brain whilst we are in a dream-state.
The overwhelming peace and euphoria that results from the DMT experience, supported by Timmerman’s study has been used to suggest its potential as a treatment for anxiety and depression. Whilst more research certainly needs to be done, Timmermann’s presentation successfully demonstrated how psychedelics are beginning to shift our understanding of the mechanisms underlying altered states of consciousness and their implications.
To find out more about Chris Timmerman and his research visit: https://www.imperial.ac.uk/department-of-medicine/research/brain-sciences/psychiatry/psychedelics/