Posts Tagged ‘consciousness’

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

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By Jerry Adler
SMITHSONIAN MAGAZINE

Telepathy, 2015: At the Center for Sensorimotor Neural Engineering of the University of Washington, a young woman dons an electroencephalogram cap, studded with electrodes that can read the minute fluctuations of voltage across her brain. She is playing a game, answering questions by turning her gaze to one of two strobe lights labeled “yes” and “no.” The “yes” light is flashing at 13 times a second, the “no” at 12, and the difference is too small for her to perceive, but sufficient for a computer to detect in the firing of neurons in her visual cortex. If the computer determines she is looking at the “yes” light, it sends a signal to a room in another building, where another woman is sitting with a magnetic coil positioned behind her head. A “yes” signal activates the magnet, causing a brief disturbance in the second subject’s visual field, a virtual flash (a “phosphene”) that she describes as akin to the appearance of heat lightning on the horizon. In this way, the first woman’s answers are conveyed to another person across the campus, going “Star Trek” one better: exchanging information between two minds that aren’t even in the same place.

For nearly all of human history, only the five natural senses were known to serve as a way into the brain, and language and gesture as the channels out. Now researchers are breaching those boundaries of the mind, moving information in and out and across space and time, manipulating it and potentially enhancing it. This experiment and others have been a “demonstration to get the conversation started,” says researcher Rajesh Rao, who conducted it along with his colleague Andrea Stocco. The conversation, which will likely dominate neuroscience for much of this century, holds the promise of new technology that will dramatically affect how we treat dementia, stroke and spinal cord injuries. But it will also be about the ethics of powerful new tools to enhance thinking, and, ultimately, the very nature of consciousness and identity.

That new study grew out of Rao’s work in “brain-computer interfaces,” which process neural impulses into signals that can control external devices. Using an EEG to control a robot that can navigate a room and pick up objects—which Rao and his colleagues demonstrated as far back as 2008—may be commonplace someday for quadriplegics.

In what Rao says was the first instance of a message sent directly from one human brain to another, he enlisted Stocco to help play a basic “Space Invaders”-type game. As one person watched the attack on a screen and communicated by using only thought the best moment to fire, the other got a magnetic impulse that caused his hand, without conscious effort, to press a button on a keyboard. After some practice, Rao says, they got quite good at it.

“That’s nice,” I said, when he described the procedure to me. “Can you get him to play the piano?”

Rao sighed. “Not with anything we’re using now.”

For all that science has studied and mapped the brain in recent decades, the mind remains a black box. A famous 1974 essay by the philosopher Thomas Nagel asked, “What Is It Like to Be a Bat?” and concluded that we will never know; another consciousness—another person’s, let alone a member of another species—can never be comprehended or accessed. For Rao and a few others to open that door a tiny crack, then, is a notable achievement, even if the work has mostly underscored how big a challenge it is, both conceptually and technologically.

The computing power and the programming are up to the challenge; the problem is the interface between brain and computer, and especially the one that goes in the direction from computer to brain. How do you deliver a signal to the right group of nerve cells among the estimated 86 billion in a human brain? The most efficient approach is an implanted transceiver that can be hard-wired to stimulate small regions of the brain, even down to a single neuron. Such devices are already in use for “deep brain stimulation,” a technique for treating patients with Parkinson’s and other disorders with electrical impulses. But it’s one thing to perform brain surgery for an incurable disease, and something else to do it as part of an experiment whose benefits are speculative at best.

So Rao used a technique that does not involve opening the skull, a fluctuating magnetic field to induce a tiny electric current in a region of the brain. It appears to be safe—his first volunteer was his collaborator, Stocco—but it is a crude mechanism. The smallest area that can be stimulated in this way, Rao says, is not quite half an inch across. This limits its application to gross motor movements, such as hitting a button, or simple yes-or-no communication.

Another way to transmit information, called focused ultrasound, appears to be capable of stimulating a region of the brain as small as a grain of rice. While the medical applications for ultrasound, such as imaging and tissue ablation, use high frequencies, from 800 kilohertz up to the megahertz range, a team led by Harvard radiologist Seung-Schik Yoo found that a frequency of 350 kilohertz works well, and apparently safely, to send a signal to the brain of a rat. The signal originated with a human volunteer outfitted with an EEG, which sampled his brainwaves; when he focused on a specific pattern of lights on a computer screen, a computer sent an ultrasound signal to the rat, which moved his tail in response. Yoo says the rat showed no ill effects, but the safety of focused ultrasound on the human brain is unproven. Part of the problem is that, unlike magnetic stimulation, the mechanism by which ultrasound waves—a form of mechanical energy—creates an electric potential isn’t fully understood. One possibility is that it operates indirectly by “popping” open the vesicles, or sacs, within the cells of the brain, flooding them with neurotransmitters, like delivering a shot of dopamine to exactly the right area. Alternatively, the ultrasound could induce cavitation—bubbling—in the cell membrane, changing its electrical properties. Yoo suspects that the brain contains receptors for mechanical stimulation, including ultrasound, which have been largely overlooked by neuroscientists. Such receptors would account for the phenomenon of “seeing stars,” or flashes of light, from a blow to the head, for instance. If focused ultrasound is proven safe, and becomes a feasible approach to a computer-brain interface, it would open up a wide range of unexplored—in fact, barely imagined—possibilities.

Direct verbal communication between individuals—a more sophisticated version of Rao’s experiment, with two connected people exchanging explicit statements just by thinking them—is the most obvious application, but it’s not clear that a species possessing language needs a more technologically advanced way to say “I’m running late,” or even “I love you.” John Trimper, an Emory University doctoral candidate in psychology, who has written about the ethical implications of brain-to-brain interfaces, speculates that the technology, “especially through wireless transmissions, could eventually allow soldiers or police—or criminals—to communicate silently and covertly during operations.” That would be in the distant future. So far, the most content-rich message sent brain-to-brain between humans traveled from a subject in India to one in Strasbourg, France. The first message, laboriously encoded and decoded into binary symbols by a Barcelona-based group, was “hola.” With a more sophisticated interface one can imagine, say, a paralyzed stroke victim communicating to a caregiver—or his dog. Still, if what he’s saying is, “Bring me the newspaper,” there are, or will be soon, speech synthesizers—and robots—that can do that. But what if the person is Stephen Hawking, the great physicist afflicted by ALS, who communicates by using a cheek muscle to type the first letters of a word? The world could surely benefit from a direct channel to his mind.

Maybe we’re still thinking too small. Maybe an analog to natural language isn’t the killer app for a brain-to-brain interface. Instead, it must be something more global, more ambitious—information, skills, even raw sensory input. What if medical students could download a technique directly from the brain of the world’s best surgeon, or if musicians could directly access the memory of a great pianist? “Is there only one way of learning a skill?” Rao muses. “Can there be a shortcut, and is that cheating?” It doesn’t even have to involve another human brain on the other end. It could be an animal—what would it be like to experience the world through smell, like a dog—or by echolocation, like a bat? Or it could be a search engine. “It’s cheating on an exam if you use your smartphone to look things up on the Internet,” Rao says, “but what if you’re already connected to the Internet through your brain? Increasingly the measure of success in society is how quickly we access, digest and use the information that’s out there, not how much you can cram into your own memory. Now we do it with our fingers. But is there anything inherently wrong about doing it just by thinking?”

Or, it could be your own brain, uploaded at some providential moment and digitally preserved for future access. “Let’s say years later you have a stroke,” says Stocco, whose own mother had a stroke in her 50s and never walked again. “Now, you go to rehab and it’s like learning to walk all over again. Suppose you could just download that ability into your brain. It wouldn’t work perfectly, most likely, but it would be a big head start on regaining that ability.”

Miguel Nicolelis, a creative Duke neuroscientist and a mesmerizing lecturer on the TED Talks circuit, knows the value of a good demonstration. For the 2014 World Cup, Nicolelis—a Brazilian-born soccer aficionado—worked with others to build a robotic exoskeleton controlled by EEG impulses, enabling a young paraplegic man to deliver the ceremonial first kick. Much of his work now is on brain-to-brain communication, especially in the highly esoteric techniques of linking minds to work together on a problem. The minds aren’t human ones, so he can use electrode implants, with all the advantages that conveys.

One of his most striking experiments involved a pair of lab rats, learning together and moving in synchrony as they communicated via brain signals. The rats were trained in an enclosure with two levers and a light above each. The left- or right-hand light would flash, and the rats learned to press the corresponding lever to receive a reward. Then they were separated, and each fitted with electrodes to the motor cortex, connected via computers that sampled brain impulses from one rat (the “encoder”), and sent a signal to a second (the “decoder”). The “encoder” rat would see one light flash—say, the left one—and push the left-hand lever for his reward; in the other box, both lights would flash, so the “decoder” wouldn’t know which lever to push—but on receiving a signal from the first rat, he would go to the left as well.

Nicolelis added a clever twist to this demonstration. When the decoder rat made the correct choice, he was rewarded, and the encoder got a second reward as well. This served to reinforce and strengthen the (unconscious) neural processes that were being sampled in his brain. As a result, both rats became more accurate and faster in their responses—“a pair of interconnected brains…transferring information and collaborating in real time.” In another study, he wired up three monkeys to control a virtual arm; each could move it in one dimension, and as they watched a screen they learned to work together to manipulate it to the correct location. He says he can imagine using this technology to help a stroke victim regain certain abilities by networking his brain with that of a healthy volunteer, gradually adjusting the proportions of input until the patient’s brain is doing all the work. And he believes this principle could be extended indefinitely, to enlist millions of brains to work together in a “biological computer” that tackled questions that could not be posed, or answered, in binary form. You could ask this network of brains for the meaning of life—you might not get a good answer, but unlike a digital computer, “it” would at least understand the question. At the same time, Nicolelis criticizes efforts to emulate the mind in a digital computer, no matter how powerful, saying they’re “bogus, and a waste of billions of dollars.” The brain works by different principles, modeling the world by analogy. To convey this, he proposes a new concept he calls “Gödelian information,” after the mathematician Kurt Gödel; it’s an analog representation of reality that cannot be reduced to bytes, and can never be captured by a map of the connections between neurons (“Upload Your Mind,” see below). “A computer doesn’t generate knowledge, doesn’t perform introspection,” he says. “The content of a rat, monkey or human brain is much richer than we could ever simulate by binary processes.”

The cutting edge of this research involves actual brain prostheses. At the University of Southern California, Theodore Berger is developing a microchip-based prosthesis for the hippocampus, the part of the mammal­ian brain that processes short-term impressions into long-term memories. He taps into the neurons on the input side, runs the signal through a program that mimics the transformations the hippocampus normally performs, and sends it back into the brain. Others have used Berger’s technique to send the memory of a learned behavior from one rat to another; the second rat then learned the task in much less time than usual. To be sure, this work has only been done in rats, but because degeneration of the hippocampus is one of the hallmarks of dementia in human beings, the potential of this research is said to be enormous.

Given the sweeping claims for the future potential of brain-to-brain communication, it’s useful to list some of the things that are not being claimed. There is, first, no implication that humans possess any form of natural (or supernatural) telepathy; the voltages flickering inside your skull just aren’t strong enough to be read by another brain without electronic enhancement. Nor can signals (with any technology we possess, or envision) be transmitted or received surreptitiously, or at a distance. The workings of your mind are secure, unless you give someone else the key by submitting to an implant or an EEG. It is, however, not too soon to start considering the ethical implications of future developments, such as the ability to implant thoughts in other people or control their behavior (prisoners, for example) using devices designed for those purposes. “The technology is outpacing the ethical discourse at this time,” Emory’s Trimper says, “and that’s where things get dicey.” Consider that much of the brain traffic in these experiments—and certainly anything like Nicolelis’ vision of hundreds or thousands of brains working together—involves communicating over the Internet. If you’re worried now about someone hacking your credit card information, how would you feel about sending the contents of your mind into the cloud?There’s another track, though, on which brain-to-brain communication is being studied. Uri Hasson, a Princeton neuroscientist, uses functional magnetic resonance imaging to research how one brain influences another, how they are coupled in an intricate dance of cues and feedback loops. He is focusing on a communication technique that he considers far superior to EEGs used with transcranial magnetic stimulation, is noninvasive and safe and requires no Internet connection. It is, of course, language.

Read more: http://www.smithsonianmag.com/innovation/why-brain-brain-communication-no-longer-unthinkable-180954948/#y1xADWfAk1VkKIJc.99

by Natalie Wolchover

The main theory of psychedelics, first fleshed out by a Swiss researcher named Franz Vollenweider, is that drugs like LSD and psilocybin, the active ingredient in “magic” mushrooms, tune down the thalamus’ activity. Essentially, the thalamus on a psychedelic drug lets unprocessed information through to consciousness, like a bad email spam filter. “Colors become brighter , people see things they never noticed before and make associations that they never made before,” Sewell said.

LSD, or acid, and its mind-bending effects have been made famous by pop culture hits like “Fear and Loathing in Las Vegas,” a film about the psychedelic escapades of writer Hunter S. Thompson. Oversaturated colors, swirling walls and intense emotions all supposedly come into play when you’re tripping. But how does acid make people trip?

Life’s Little Mysteries asked Andrew Sewell, a Yale psychiatrist and one of the few U.S.-based psychedelic drug researchers, to explain why LSD short for lysergic acid diethylamide does what it does to the brain.

His explanation begins with a brief rundown of how the brain processes information under normal circumstances. It all starts in the thalamus, a node perched on top of the brain stem, right smack dab in the middle of the brain. “Most sensory impressions are routed through the thalamus, which acts as a gatekeeper, determining what’s relevant and what isn’t and deciding where the signals should go,” Sewell said.

“Consequently, your perception of the world is governed by a combination of ‘bottom-up’ processing, starting … with incoming signals, combined with ‘top-down’ processing, in which selective filters are applied by your brain to cut down the overwhelming amount of information to a more manageable and relevant subset that you can then make decisions about.

“In other words, people tend to see what they’ve been trained to see, and hear what they’ve been trained to hear.”

The main theory of psychedelics, first fleshed out by a Swiss researcher named Franz Vollenweider, is that drugs like LSD and psilocybin, the active ingredient in “magic” mushrooms, tune down the thalamus’ activity. Essentially, the thalamus on a psychedelic drug lets unprocessed information through to consciousness, like a bad email spam filter. “Colors become brighter , people see things they never noticed before and make associations that they never made before,” Sewell said.

n a recent paper advocating the revival of psychedelic drug research, psychiatrist Ben Sessa of the University of Bristol in England explained the benefits that psychedelics lend to creativity. “A particular feature of the experience is … a general increase in complexity and openness, such that the usual ego-bound restraints that allow humans to accept given pre-conceived ideas about themselves and the world around them are necessarily challenged. Another important feature is the tendency for users to assign unique and novel meanings to their experience together with an appreciation that they are part of a bigger, universal cosmic oneness.”

But according to Sewell, these unique feelings and experiences come at a price: “disorganization, and an increased likelihood of being overwhelmed.” At least until the drugs wear off, and then you’re left just trying to make sense of it all.

http://www.livescience.com/33167-how-acid-lsd-make-people-trip.html?li_source=pm&li_medium=most-popular&li_campaign=related_test

ONE moment you’re conscious, the next you’re not. For the first time, researchers have switched off consciousness by electrically stimulating a single brain area.

Scientists have been probing individual regions of the brain for over a century, exploring their function by zapping them with electricity and temporarily putting them out of action. Despite this, they have never been able to turn off consciousness – until now.

Although only tested in one person, the discovery suggests that a single area – the claustrum – might be integral to combining disparate brain activity into a seamless package of thoughts, sensations and emotions. It takes us a step closer to answering a problem that has confounded scientists and philosophers for millennia – namely how our conscious awareness arises.

Many theories abound but most agree that consciousness has to involve the integration of activity from several brain networks, allowing us to perceive our surroundings as one single unifying experience rather than isolated sensory perceptions.

One proponent of this idea was Francis Crick, a pioneering neuroscientist who earlier in his career had identified the structure of DNA. Just days before he died in July 2004, Crick was working on a paper that suggested our consciousness needs something akin to an orchestra conductor to bind all of our different external and internal perceptions together.

With his colleague Christof Koch, at the Allen Institute for Brain Science in Seattle, he hypothesised that this conductor would need to rapidly integrate information across distinct regions of the brain and bind together information arriving at different times. For example, information about the smell and colour of a rose, its name, and a memory of its relevance, can be bound into one conscious experience of being handed a rose on Valentine’s day.

The pair suggested that the claustrum – a thin, sheet-like structure that lies hidden deep inside the brain – is perfectly suited to this job (Philosophical Transactions of The Royal Society B, doi.org/djjw5m).

It now looks as if Crick and Koch were on to something. In a study published last week, Mohamad Koubeissi at the George Washington University in Washington DC and his colleagues describe how they managed to switch a woman’s consciousness off and on by stimulating her claustrum. The woman has epilepsy so the team were using deep brain electrodes to record signals from different brain regions to work out where her seizures originate. One electrode was positioned next to the claustrum, an area that had never been stimulated before.

When the team zapped the area with high frequency electrical impulses, the woman lost consciousness. She stopped reading and stared blankly into space, she didn’t respond to auditory or visual commands and her breathing slowed. As soon as the stimulation stopped, she immediately regained consciousness with no memory of the event. The same thing happened every time the area was stimulated during two days of experiments (Epilepsy and Behavior, doi.org/tgn).
To confirm that they were affecting the woman’s consciousness rather than just her ability to speak or move, the team asked her to repeat the word “house” or snap her fingers before the stimulation began. If the stimulation was disrupting a brain region responsible for movement or language she would have stopped moving or talking almost immediately. Instead, she gradually spoke more quietly or moved less and less until she drifted into unconsciousness. Since there was no sign of epileptic brain activity during or after the stimulation, the team is sure that it wasn’t a side effect of a seizure.

Koubeissi thinks that the results do indeed suggest that the claustrum plays a vital role in triggering conscious experience. “I would liken it to a car,” he says. “A car on the road has many parts that facilitate its movement – the gas, the transmission, the engine – but there’s only one spot where you turn the key and it all switches on and works together. So while consciousness is a complicated process created via many structures and networks – we may have found the key.”

Counter-intuitively, Koubeissi’s team found that the woman’s loss of consciousness was associated with increased synchrony of electrical activity, or brainwaves, in the frontal and parietal regions of the brain that participate in conscious awareness. Although different areas of the brain are thought to synchronise activity to bind different aspects of an experience together, too much synchronisation seems to be bad. The brain can’t distinguish one aspect from another, stopping a cohesive experience emerging.

Since similar brainwaves occur during an epileptic seizure, Koubeissi’s team now plans to investigate whether lower frequency stimulation of the claustrum could jolt them back to normal. It may even be worth trying for people in a minimally conscious state, he says. “Perhaps we could try to stimulate this region in an attempt to push them out of this state.”

Anil Seth, who studies consciousness at the University of Sussex, UK, warns that we have to be cautious when interpreting behaviour from a single case study. The woman was missing part of her hippocampus, which was removed to treat her epilepsy, so she doesn’t represent a “normal” brain, he says.

However, he points out that the interesting thing about this study is that the person was still awake. “Normally when we look at conscious states we are looking at awake versus sleep, or coma versus vegetative state, or anaesthesia.” Most of these involve changes of wakefulness as well as consciousness but not this time, says Seth. “So even though it’s a single case study, it’s potentially quite informative about what’s happening when you selectively modulate consciousness alone.”

“Francis would have been pleased as punch,” says Koch, who was told by Crick’s wife that on his deathbed, Crick was hallucinating an argument with Koch about the claustrum and its connection to consciousness.

“Ultimately, if we know how consciousness is created and which parts of the brain are involved then we can understand who has it and who doesn’t,” says Koch. “Do robots have it? Do fetuses? Does a cat or dog or worm? This study is incredibly intriguing but it is one brick in a large edifice of consciousness that we’re trying to build.”

http://www.newscientist.com/article/mg22329762.700-consciousness-onoff-switch-discovered-deep-in-brain.html?full=true#.U7n7sI1dVC8

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.