Posts Tagged ‘synesthesia’

By Bahar Gholipour

The consciousness-altering drug LSD is best known for its bizarre visual effects: even a small dose of the drug can turn the flat walls of your living room into something out of Wonderland. Objects bend, colors blend and intricate patterns cast a shimmer on everything you see. But what would LSD feel like if you couldn’t see?

In an unusual case report published in the April issue of the journal Cognition and Consciousness, a blind 70-year-old former rock musician has some answers.

The man, who is referred to as “Mr. Blue Pentagon” after his favorite kind of LSD, gave researchers a detailed account of what he experienced when taking the drug during his music career in the 1970s. Mr. Pentagon was born blind. He did not perceive vision, with or without LSD. Instead, under the influence of psychedelics, he had strong auditory and tactile hallucinations, including an overlap of the two in a form of synesthesia, according to the report.

“I never had any visual images come to me. I can’t see or imagine what light or dark might look like,” Mr. Blue Pentagon told the researchers. But under the influence of LSD (lysergic acid diethylamide, also known as acid), sounds felt unique and listening to music felt like being immersed in a waterfall, he said. “The music of Bach’s third Brandenburg concerto brought on the waterfall effect. I could hear violins playing in my soul and found myself having a one hour long monologue using different tones of voices … LSD gave everything ‘height.’ The sounds coming from songs I would normally listen to became three dimensional, deep and delayed.”

Mr. Blue Pentagon’s account is a rare glimpse into how LSD may feel in the absence of vision. Beyond a few Q&A threads on Reddit, the only other resource is a 1963 study of 24 blind people, which was actually conducted by an ophthalmologist to test whether a functioning retina (the part of the eye that senses light) is enough for visual hallucinations (it’s not), and didn’t include the participants’ psychological experiences beyond vision.

Understanding Mr. Blue Pentagon’s experience with the drugmay give unique insights about how novel synesthetic experiences through multiple senses are concocted by the brain — especially a brain that is wired differently due to lack of vision, according to the researchers from the University of Bath in the U.K. who published the report. Synesthesia is a rare condition in which one sense is perceived in the form of another; for example, a person may “hear” colors or “taste” sounds. This overlap of senses may ocurr because of cross communication between brain networks processing each sense, scientists have proposed.

As numerous anecdotal reports suggest and a few studies have documented, LSD causes auditory-visual synesthesia, an experience in which sounds and sights influence each other. Mr. Blue Pentagon appeared to experience a similar phenomenon, but rather than mixing sound and sight, it involved the senses that were available to him: sound and touch, the researchers suggested.

Still, there’s only so much to be gleaned from a qualitative report based on a single person.

“It is next to impossible to gain ‘general’ insights from individual narratives,” said Ilsa Jerome, a clinical researcher for the Multidisciplinary Association for Psychedelic Studies (MAPS) who was not involved with the report.

Jerome, who is visually impaired herself, said she is unconvinced that having a visual impairment provides any special insight on how LSD alters sensory processes. “But it might provide greater motivation or interest in the sensory impact of psychedelic compounds,” she told Live Science.

The brain in blindness
The details of what exactly LSD does in the brain are still unclear, but research suggests that the drug’s psychedelic effects occur because LSD alters neuronal communication in the brain. Specifically, LSD latches onto receptors for serotonin, one of the neurotranmitters neurons use to communicate. The visual hallucinations are likely a result of LSD stimulating these receptors in the visual cortex, the part of the brain that processes light, color and other visual information. [10 Things You Didn’t Know About the Brain]

The first studyto look at the brain effects of LSD using modern technology was published recently, in 2016, in the journal Proceedings of the National Academy of Sciences. In that study, when people took LSD, the researchers observed that the visual cortex was unusually activeand showed greater synchronous activity with many areas of the brain. This connectivity was correlated with the complex visual hallucinations reported by the participants.

The visual cortex develops into a fully functioning system during early life in response to sensory information from the eyes. But in the absence of early visual experience, which is the case for people born blind, the visual cortex doesn’t develop normally. Instead, it rewires to process sound and touch.

This could explain the nature of Mr. Blue Pentagon’s experience with LSD.

“I expect that the cortical ‘real estate’ that would have housed vision does not do so in Mr. Pentagon’s case,” Jerome said. “So LSD may be doing the same thing with that area of cortex, but since that area is, for him, connected with other senses, those experiences — such as sound, touch or sense of self in space — are altered.”

Visual or other sensory hallucinations are only one part of LSD’s effects. The compound can cause profound changes in emotions and consciousness, all of which are reported by both blind and sighted people. The few studies that exist on the subject suggest LSD may be doing this by lowering the barriers between brain networks, allowing them to communicate in a more flexible way.

Original article on Live Science.

https://www.livescience.com/62343-psychedelics-lsd-effects-blind-people.html

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By Tereza Pultarova

About 4 percent of the people on Earth experience a mysterious phenomenon called synesthesia: They hear a sound and automatically see a color; or, they read a certain word, and a specific hue enters their mind’s eye. The condition has long puzzled scientists, but a small new study may offer some clues.

The study, published March 5 in the journal Proceedings of the National Academy of Sciences, offers insight into what might be happening in the brains of people with synesthesia.

Previous “studies of brain function using magnetic resonance imaging confirm that synesthesia is a real biological phenomenon,” said senior study author Simon Fisher, director of the Max Planck Institute for Psycholinguistics in the Netherlands. For example, when people with synesthesia “hear” color, brain scans show that there’s activity in the parts of the brain linked to both sight and sound, he said. (Not all people with the condition “hear” sights, however; the condition can also link other senses.)Indeed, the brains of people with synesthesia previously have been shown to be more connected across different regions than the brains of people whose senses are not cross-linked, Fisher told Live Science. The question, however, was what causes this different brain wiring, he said.

To answer that question, Fisher and his team looked to genetics.

Synesthesia frequently runs in families, so the researchers decided to look for genes that might be responsible for the development of the condition. They chose three families, in which multiple members across at least three generations had a specific type of synesthesia, the so-called sound-color synesthesia, meaning that hearing sounds evokes perceptions of colors. Typically, a specific sound or musical tone is consistently associated with a specific color for people who have this type of synesthesia. However, different members of a single family can see different colors when hearing the same sound, Fisher said.

The scientists used DNA sequencing to study the participants’ genes, Fisher said. Then, to identify genes that might be responsible for the condition, the scientists compared the genes of family members with synesthesia to the genes of family members without it, he said.

But the findings didn’t yield a straightforward result: “There was not a single gene that could explain synesthesia in all three families,” Fisher said. Instead, “there were 37 candidate variants,” or possible gene variations, he said.

Because the study included only a small number of people, there wasn’t enough data to single out the specific genes, of the 37 possibilities, that played a role in synesthesia. So, instead, the scientists looked at the biological functions of each gene to see how it could be related to the development of the condition. “There were just a few biological themes that were significantly enriched across the candidate genes identified,” Fisher said. “One of those was axonogenesis, a crucial process helping neurons get wired up to each other in the developing brain.” Axonogenesis refers to the development of neurons.

This is consistent with prior findings of altered connectivity in brain scans of people with synesthesia, Fisher said. In other words, the genes identified in the study play a role in how the brain is wired, offering a potential explanation for why the brains of people with synesthesia appear to be wired differently.

https://www.livescience.com/61930-synesthesia-hear-colors-genes.html

lsd

by Angus Chen

Some users of LSD say one of the most profound parts of the experience is a deep oneness with the universe. The hallucinogenic drug might be causing this by blurring boundaries in the brain, too.

The sensation that the boundaries between yourself and the world around you are erasing correlates to changes in brain connectivity while on LSD, according to a study published Wednesday in Current Biology. Scientists gave 15 volunteers either a drop of acid or a placebo and slid them into an MRI scanner to monitor brain activity.

After about an hour, when the high begins peaking, the brains of people on acid looked markedly different than those on the placebo. For those on LSD, activity in certain areas of their brain, particularly areas rich in neurons associated with serotonin, ramped up.

Their sensory cortices, which process sensations like sight and touch, became far more connected than usual to the frontal parietal network, which is involved with our sense of self. “The stronger that communication, the stronger the experience of the dissolution [of self],” says Enzo Tagliazucchi, the lead author and a researcher at the Netherlands Institute for Neuroscience.

Tagliazucchi speculates that what’s happening is a confusion of information. Your brain on acid, flooded with signals crisscrossing between these regions, begins muddling the things you see, feel, taste or hear around you with you. This can create the perception that you and, say, the pizza you’re eating are no longer separate entities. You are the pizza and the world beyond the windowsill. You are the church and the tree and the hill.

Albert Hofmann, the discoverer of LSD, described this in his book LSD: My Problem Child. “A portion of the self overflows into the outer world, into objects, which begin to live, to have another, a deeper meaning,” he wrote. He felt the world would be a better place if more people understood this. “What is needed today is a fundamental re-experience of the oneness of all living things.”

The sensation is neurologically similar to synesthesia, Tagliazucchi thinks. “In synesthesia, you mix up sensory modalities. You can feel the color of a sound or smell the sound. This happens in LSD, too,” Tagliazucchi says. “And ego dissolution is a form of synesthesia, but it’s a synesthesia of areas of brain with consciousness of self and the external environment. You lose track of which is which.”

Tagliazucchi and other researchers also measured the volunteers’ brain electrical activity with another device. Our brains normally generate a regular rhythm of electrical activity called the alpha rhythm, which links to our brain’s ability to suppress irrelevant activity. But in a different paper published on Monday in the Proceedings of the National Academy of Sciences, he and several co-authors show that LSD weakens the alpha rhythm. He thinks this weakening could make the hallucinations seem more real.

The idea is intriguing if still somewhat speculative, says Dr. Charles Grob, a psychiatrist at the Harbor-UCLA Medical Center who was not involved with the work. “They may genuinely be on to something. This should really further our understanding of the brain and consciousness.” And, he says, the work highlights hallucinogens’ powerful therapeutic potential.

The altered state of reality that comes with psychedelics might enhance psychotherapy, Grob thinks. “Hallucinogens are a catalyst,” he says. “In well-prepared subjects, you might elicit powerful, altered states of consciousness. [That] has been predicative of positive therapeutic outcomes.”

In recent years, psychedelics have been trickling their way back to psychiatric research. LSD was considered a good candidate for psychiatric treatment until 1966, when it was outlawed and became very difficult to obtain for study. Grob has done work testing the treatment potential of psilocybin, the active compound in hallucinogenic mushrooms.

He imagines a future where psychedelics are commonly used to treat a range of conditions. “[There could] be a peaceful room attractively fixed up with nice paintings, objects to look at, fresh flowers, a chair or recliner for the patient and two therapists in the room,” he muses. “A safe container for that individual as they explore deep inner space, inner terrain.”

Grob believes the right candidate would benefit greatly from LSD or other hallucinogen therapy, though he cautions that bad experiences can still happen for some on the drugs. Those who are at risk for schizophrenia may want to avoid psychedelics, Tagliazucchi says. “There has been evidence saying what could happen is LSD could trigger the disease and turn it into full-fledged schizophrenia,” he says. “There is a lot of debate around this. It’s an open topic.”

Tagliazucchi thinks that this particular ability of psychedelics to evoke a sense of dissolution of self and unity with the external environment has already helped some patients. “Psilocybin has been used to treat anxiety with terminal cancer patients,” he says. “One reason why they felt so good after treatment is the ego dissolution is they become part of something larger: the universe. This led them to a new perspective on their death.”

http://www.npr.org/sections/health-shots/2016/04/13/474071268/how-lsd-makes-your-brain-one-with-the-universe