Evidence of a 'higher' state of consciousness?
Image created using brain imaging technology, showing changes in neural signal diversity while under the influence of LSD. Credit: Image courtesy of University of Sussex
Impact of psychedelics on neural signal diversity measured
April 19, 2017
Science Daily/University of Sussex
Scientific evidence of a 'higher' state of consciousness has been found in a study led by the University of Sussex.
Neuroscientists observed a sustained increase in neural signal diversity -- a measure of the complexity of brain activity -- of people under the influence of psychedelic drugs, compared with when they were in a normal waking state.
The diversity of brain signals provides a mathematical index of the level of consciousness. For example, people who are awake have been shown to have more diverse neural activity using this scale than those who are asleep.
This, however, is the first study to show brain-signal diversity that is higher than baseline, that is higher than in someone who is simply 'awake and aware'. Previous studies have tended to focus on lowered states of consciousness, such as sleep, anaesthesia, or the so-called 'vegetative' state.
The team say that more research is needed using more sophisticated and varied models to confirm the results but they are cautiously excited.
Professor Anil Seth, Co-Director of the Sackler Centre for Consciousness Science at the University of Sussex, said: "This finding shows that the brain-on-psychedelics behaves very differently from normal.
"During the psychedelic state, the electrical activity of the brain is less predictable and less 'integrated' than during normal conscious wakefulness -- as measured by 'global signal diversity'.
"Since this measure has already shown its value as a measure of 'conscious level', we can say that the psychedelic state appears as a higher 'level' of consciousness than normal -- but only with respect to this specific mathematical measure."
For the study, Michael Schartner, Adam Barrett and Professor Seth of the Sackler Centre reanalysed data that had previously been collected by Imperial College London and the University of Cardiff in which healthy volunteers were given one of three drugs known to induce a psychedelic state: psilocybin, ketamine and LSD.
Using brain imaging technology, they measured the tiny magnetic fields produced in the brain and found that, across all three drugs, this measure of conscious level -- the neural signal diversity -- was reliably higher.
This does not mean that the psychedelic state is a 'better' or more desirable state of consciousness, the researchers stress; instead, it shows that the psychedelic brain state is distinctive and can be related to other global changes in conscious level (e.g. sleep, anaesthesia) by application of a simple mathematical measure of signal diversity. Dr Muthukumaraswamy who was involved in all three initial studies commented: "That similar changes in signal diversity were found for all three drugs, despite their quite different pharmacology, is both very striking and also reassuring that the results are robust and repeatable."
The findings could help inform discussions gathering momentum about the carefully-controlled medical use of such drugs, for example in treating severe depression.
Dr Robin Cahart-Harris of Imperial College London said: "Rigorous research into psychedelics is gaining increasing attention, not least because of the therapeutic potential that these drugs may have when used sensibly and under medical supervision.
"The present study's findings help us understand what happens in people's brains when they experience an expansion of their consciousness under psychedelics. People often say they experience insight under these drugs -- and when this occurs in a therapeutic context, it can predict positive outcomes. The present findings may help us understand how this can happen."
As well as helping to inform possible medical applications, the study adds to a growing scientific understanding of how conscious level (how conscious one is) and conscious content (what one is conscious of) are related to each other.
Professor Seth said: "We found correlations between the intensity of the psychedelic experience, as reported by volunteers, and changes in signal diversity. This suggests that our measure has close links not only to global brain changes induced by the drugs, but to those aspects of brain dynamics that underlie specific aspects of conscious experience."
The research team are now working hard to identify how specific changes in information flow in the brain underlie specific aspects of psychedelic experience, like hallucinations.
https://www.sciencedaily.com/releases/2017/04/170419091624.htm
First study to explore language and LSD since the 1960s: New study shows LSD's effects on language
August 18, 2016
Science Daily/Technische Universität Kaiserslautern
The consumption of LSD, short for lysergic acid diethylamide, can produce altered states of consciousness. This can lead to a loss of boundaries between the self and the environment, as might occur in certain psychiatric illnesses. David Nutt, professor of Neuropsychopharmacology at Imperial College, leads a team of researchers who study how this psychedelic substance works in the brain.
In this study, Dr. Neiloufar Family, post-doc from the University of Kaiserslautern, investigates how LSD can affect speech and language. She asked ten participants to name a sequence of pictures both under placebo and under the effects of LSD, one week apart.
"Results showed that while LSD does not affect reaction times," explains lead author Neiloufar Family, "people under LSD made more mistakes that were similar in meaning to the pictures they saw." For example, when people saw a picture of a car, they would accidentally say 'bus' or 'train' more often under LSD than under placebo. This indicates that LSD seems to effect the mind's semantic networks, or how words and concepts are stored in relation to each other. When LSD makes the network activation stronger, more words from the same family of meanings come to mind.
The results from this experiment can lead to a better understanding of the neurobiological basis of semantic network activation. Neiloufar Family explains further implication: "These findings are relevant for the renewed exploration of psychedelic psychotherapy, which are being developed for depression and other mental illnesses. The effects of LSD on language can result in a cascade of associations that allow quicker access to far away concepts stored in the mind."
The many potential uses of this class of substances are under scientific debate. "Inducing a hyper-associative state may have implications for the enhancement of creativity," Family adds. The increase in activation of semantic networks can lead distant or even subconscious thoughts and concepts to come to the surface.
This article was published in the academic journal Language, Cognition and Neuroscience under the title: "Semantic activation in LSD: evidence from picture naming."
https://www.sciencedaily.com/releases/2016/08/160818090035.htm
Brain on LSD revealed: First scans show how the drug affects the brain
The areas that contributed to vision were more active under LSD, which was linked to hallucinations. Credit: Image courtesy of Imperial College London
April 11, 2016
Science Daily/Imperial College London
For the first time, researchers have visualized the effects of LSD on the human brain. In a series of experiments, scientists have gained a glimpse into how the psychedelic compound affects brain activity. The team administered LSD (Lysergic acid diethylamide) to 20 healthy volunteers in a specialist research centre and used various leading-edge and complementary brain scanning techniques to visualize how LSD alters the way the brain works.
Researchers from Imperial College London, working with the Beckley Foundation, have for the first time visualized the effects of LSD on the human brain.
In a series of experiments, scientists have gained a glimpse into how the psychedelic compound affects brain activity. The team administered LSD (Lysergic acid diethylamide) to 20 healthy volunteers in a specialist research centre and used various leading-edge and complementary brain scanning techniques to visualize how LSD alters the way the brain works.
The findings, published in Proceedings of the National Academy of Sciences (PNAS), reveal what happens in the brain when people experience the complex visual hallucinations that are often associated with LSD state. They also shed light on the brain changes that underlie the profound altered state of consciousness the drug can produce.
A major finding of the research is the discovery of what happens in the brain when people experience complex dreamlike hallucinations under LSD. Under normal conditions, information from our eyes is processed in a part of the brain at the back of the head called the visual cortex. However, when the volunteers took LSD, many additional brain areas -- not just the visual cortex -- contributed to visual processing.
Dr Robin Carhart-Harris, from the Department of Medicine at Imperial, who led the research, explained: "We observed brain changes under LSD that suggested our volunteers were 'seeing with their eyes shut' -- albeit they were seeing things from their imagination rather than from the outside world. We saw that many more areas of the brain than normal were contributing to visual processing under LSD -- even though the volunteers' eyes were closed. Furthermore, the size of this effect correlated with volunteers' ratings of complex, dreamlike visions. "
The study also revealed what happens in the brain when people report a fundamental change in the quality of their consciousness under LSD.
Dr Carhart-Harris explained: "Normally our brain consists of independent networks that perform separate specialised functions, such as vision, movement and hearing -- as well as more complex things like attention. However, under LSD the separateness of these networks breaks down and instead you see a more integrated or unified brain.
"Our results suggest that this effect underlies the profound altered state of consciousness that people often describe during an LSD experience. It is also related to what people sometimes call 'ego-dissolution', which means the normal sense of self is broken down and replaced by a sense of reconnection with themselves, others and the natural world. This experience is sometimes framed in a religious or spiritual way -- and seems to be associated with improvements in well-being after the drug's effects have subsided."
Dr Carhart-Harris added: "Our brains become more constrained and compartmentalized as we develop from infancy into adulthood, and we may become more focused and rigid in our thinking as we mature. In many ways, the brain in the LSD state resembles the state our brains were in when we were infants: free and unconstrained. This also makes sense when we consider the hyper-emotional and imaginative nature of an infant's mind."
In addition to these findings, research from the same group, part of the Beckley/Imperial Research Programme, revealed that listening to music while taking LSD triggered interesting changes in brain signalling that were associated with eyes-closed visions.
In a study published in the journal European Neuropsychopharmacology, the researchers found altered visual cortex activity under the drug, and that the combination of LSD and music caused this region to receive more information from an area of the brain called the parahippocampus. The parahippocampus is involved in mental imagery and personal memory, and the more it communicated with the visual cortex, the more people reported experiencing complex visions, such as seeing scenes from their lives.
PhD student Mendel Kaelen from the Department of Medicine at Imperial, who was lead author of the music paper, said: "This is the first time we have witnessed the interaction of a psychedelic compound and music with the brain's biology.
The Beckley/Imperial Research Programme hope these collective findings may pave the way for these compounds being one day used to treat psychiatric disorders. They could be particularly useful in conditions where negative thought patterns have become entrenched, say the scientists, such as in depression or addiction.
Mendel Kaelen added: "A major focus for future research is how we can use the knowledge gained from our current research to develop more effective therapeutic approaches for treatments such as depression; for example, music-listening and LSD may be a powerful therapeutic combination if provided in the right way."
Professor David Nutt, the senior researcher on the study and Edmond J Safra Chair in Neuropsychopharmacology at Imperial, said: "Scientists have waited 50 years for this moment -- the revealing of how LSD alters our brain biology. For the first time we can really see what's happening in the brain during the psychedelic state, and can better understand why LSD had such a profound impact on self-awareness in users and on music and art. This could have great implications for psychiatry, and helping patients overcome conditions such as depression."
Amanda Feilding, Director of the Beckley Foundation, said: "We are finally unveiling the brain mechanisms underlying the potential of LSD, not only to heal, but also to deepen our understanding of consciousness itself."
The research involved 20 healthy volunteers -- each of whom received both LSD and placebo -- and all of whom were deemed psychologically and physically healthy. All the volunteers had previously taken some type of psychedelic drug. During carefully controlled and supervised experiments in a specialist research centre, each volunteer received an injection of either 75 micrograms of LSD, or placebo. Their brains were then scanned using various techniques including fMRI and magnetoencephalography (MEG). These enabled the researchers to study activity within the whole of the brain by monitoring blood flow and electrical activity.
https://www.sciencedaily.com/releases/2016/04/160411153006.htm
LSD changes consciousness by reorganizing human brain networks
December 10, 2015
Science Daily/American College of Neuropsychopharmacology
LSD is known to cause changes in consciousness, including "ego-dissolution," or a loss of the sense of self. Despite a detailed knowledge of the action of LSD at specific serotonin receptors, it has not been understood how this these pharmacological effects can translate into such a profound effect on consciousness. Now, a new report presented at the annual meeting of the American College of Neuropsychopharmacology in Hollywood, Florida, provides evidence to show that LSD reduces connectivity within brain networks, or the extent to which nerve cells or neurons within a network fire in synchrony. LSD also seems to reduce the extent to which separate brain networks remain distinct in their patterns or synchronization of firing. Overall, LSD interferes with the patterns of activation in the different brain networks that underlie human thought and behavior.
In this new study, Dr. Robin Carhart-Harris and his colleagues at Imperial College London did sequential brain scans of 20 healthy volunteers over 6 hours, using functional magnetic resonance imaging (fMRI), which maps brain activity by detecting changes in blood flow, and magnetoencephalography (MEG), a technique that images brain function by recording magnetic fields produced by electrical currents occurring in the brain. Using fMRI, the investigators showed that LSD led to a more chaotic brain state not entirely dissimilar to what is seen in the prodromal phase of psychosis. Specifically, neurons that were supposed to fire together within a network fell out of synchrony, while networks that are normally distinct started to overlap in their connectivity patterns. Dr. Carhart-Harris also found increases in blood flow in the visual cortex at the back of the brain, which might explain the visual hallucinations and distortions so common in LSD intoxication. MEG also showed a change in natural brain oscillations, specifically a decrease in alpha waves across the brain. The MEG changes were highly correlated with visual hallucinations, suggesting that under the influence of LSD, the visual system is tethered more to the internal than to the external world.
Dr. Carhart-Harris suggests that "with better assessment tools available today than in the 1950's and 1960's, it may be possible to evaluate potential uses of LSD as a treatment for addiction and other disorders, such as treatment-resistant depression -- which we are currently investigating with a similar drug to LSD." LSD also may provide a useful human model of psychosis, as it leads to changes in brain network behavior that shows overlap with the early phase of psychosis.
https://www.sciencedaily.com/releases/2015/12/151210144910.htm