Tag: consciousness

Recordings reveal that plants make ultrasonic squeals when stressed

On By A.P.In UncategorizedLeave a comment

Although it has been revealed in recent years that plants are capable of seeing, hearing and smelling, they are still usually thought of as silent. But now, for the first time, they have been recorded making airborne sounds when stressed, which researchers say could open up a new field of precision agriculture where farmers listen for water-starved crops.

Itzhak Khait and his colleagues at Tel Aviv University in Israel found that tomato and tobacco plants made sounds at frequencies humans cannot hear when stressed by a lack of water or when their stem is cut.

Microphones placed 10 centimetres from the plants picked up sounds in the ultrasonic range of 20 to 100 kilohertz, which the team says insects and some mammals would be capable of hearing and responding to from as far as 5 metres away. A moth may decide against laying eggs on a plant that sounds water-stressed, the researchers suggest. Plants could even hear that other plants are short of water and react accordingly, they speculate.

“These findings can alter the way we think about the plant kingdom, which has been considered to be almost silent until now,” they write in their study, which has not yet been published in a journal.

Previously, devices have been attached to plants to record the vibrations caused by air bubbles forming and exploding – a process known as cavitation – inside xylem tubes, which are used for water transport. But this new study is the first time that sounds from plants have been measured at a distance.

On average, drought-stressed tomato plants made 35 sounds an hour, while tobacco plants made 11. When plant stems were cut, tomato plants made an average of 25 sounds in the following hour, and tobacco plants 15. Unstressed plants produced fewer than one sound per hour, on average.

It is even possible to distinguish between the sounds to know what the stress is. The researchers trained a machine-learning model to discriminate between the plants’ sounds and the wind, rain and other noises of the greenhouse, correctly identifying in most cases whether the stress was caused by dryness or a cut, based on the sound’s intensity and frequency. Water-hungry tobacco appears to make louder sounds than cut tobacco, for example.

Although Khait and his colleagues only looked at tomato and tobacco plants, they believe other plants may make sounds when stressed too. In a preliminary study, they also recorded ultrasonic sounds from a spiny pincushion cactus (Mammillaria spinosissima) and the weed henbit dead-nettle (Lamium amplexicaule). Cavitation is a possible explanation for how the plants generate the sounds, they say.

Enabling farmers to listen for water-stressed plants could “open a new direction in the field of precision agriculture”, the researchers suggest. They add that such an ability will be increasingly important as climate change exposes more areas to drought.

“The suggestion that the sounds that drought-stressed plants make could be used in precision agriculture seems feasible if it is not too costly to set up the recording in a field situation,” says Anne Visscher at the Royal Botanic Gardens, Kew, in the UK.

She warns that the results can’t yet be broadened out to other stresses, such as salt or temperature, because these may not lead to sounds. In addition, there have been no experiments to show whether moths or any other animal can hear and respond to the sounds the plants make, so that idea remains speculative for now, she says.

If plants are making sounds when stressed, cavitation is the most likely mechanism, says Edward Farmer at the University of Lausanne, Switzerland. But he is sceptical of the findings, and would like to see more in the way of controls, such as the sounds of drying soil without plants in it.

Farmer adds that the idea moths might be listening to plants and shunning stressed ones is a “little too speculative”, and there are already plenty of explanations for why insects avoid some plants and not others.

Reference: bioRxiv, DOI: 10.1101/507590

Read more: https://www.newscientist.com/article/2226093-recordings-reveal-that-plants-make-ultrasonic-squeals-when-stressed/#ixzz67G8PmFZm

Ayahuasca compound changes brainwaves to vivid ‘waking-dream’ state

On By A.P.In UncategorizedLeave a comment

Scientists have peered inside the brain to show how taking DMT affects human consciousness by significantly altering the brain’s electrical activity.

DMT (or dimethyltryptamine) is one of the main psychoactive constituents in ayahuasca, the psychedelic brew traditionally made from vines and leaves of the Amazon rainforest. The drink is typically prepared as part of a shamanic ceremony and associated with unusual and vivid visions or hallucinations.

The latest study is the first to show how the potent psychedelic changes our waking brain waves – with researchers comparing its powerful effects to ‘dreaming while awake’.

The work, led by researchers from the Centre for Psychedelic Research at Imperial College London and published today in the journal Scientific Reports, may help to explain why people taking DMT and ayahuasca experience intense visual imagery and immersive ‘waking-dream’ like experiences.

DMT is a naturally occurring chemical found in miniscule amounts in the human brain but also in larger amounts in a number of plant species around the world.

Accounts from people who have taken DMT report intense visual hallucinations often accompanied by strong emotional experiences and even ‘breakthroughs’ into what users describe as an alternate reality or dimension.

But scientists are interested in using the powerful psychoactive compound for research as it produces relatively short but intense psychedelic experiences, providing a window for collecting data on brain activity when consciousness is profoundly altered.

In the latest study, the Imperial team captured EEG measures from healthy participants in a clinical setting, in a placebo-controlled design.

A total of 13 participants were given an intravenous infusion of DMT at the National Institute for Health Research (NIHR) Imperial Clinical Research Facility.

Volunteers were fitted with caps with electrodes to measure the brain’s electrical activity, before, during and after their infusion, with the peak of the psychedelic experience lasting around 10 minutes.

Analysis revealed that DMT significantly altered electrical activity in the brain, characterised by a marked drop off in alpha waves – the human brain’s dominant electrical rhythm when we are awake. They also found a short-lived increase in brainwaves typically associated with dreaming, namely, theta waves.

In addition to changes in the types of brainwaves, they also found that, overall, brain activity became more chaotic and less predictable – the opposite to what is seen in states of reduced consciousness, such as in deep sleep or under general anaesthesia.

“The changes in brain activity that accompany DMT are slightly different from what we see with other psychedelics, such as psilocybin or LSD, where we see mainly only reductions in brainwaves,” said lead author Christopher Timmermann, from the Centre for Psychedelic Research.

“Here we saw an emergent rhythm that was present during the most intense part of the experience, suggesting an emerging order amidst the otherwise chaotic patterns of brain activity. From the altered brainwaves and participants’ reports, it’s clear these people are completely immersed in their experience – it’s like daydreaming only far more vivid and immersive, it’s like dreaming but with your eyes open.”

Mr Timmermann explains that while it’s unclear as to whether DMT may have any clinical potential at this stage, the group hopes to take the work further by delivering a continuous infusion of DMT to extend the window of the psychedelic experience and collect more data.

The team says future studies could include more sophisticated measurements of brain activity, such as fMRI, to show which regions and networks of the brain are affected by DMT. They believe the visual cortex, the large area towards the back of the brain, is likely to be involved.

Dr Robin Carhart-Harris, head of Centre for Psychedelic Research, said: “DMT is a particularly intriguing psychedelic. The visual vividness and depth of immersion produced by high-doses of the substance seems to be on a scale above what is reported with more widely studied psychedelics such as psilocybin or ‘magic mushrooms’.

“It’s hard to capture and communicate what it is like for people experiencing DMT but likening it to dreaming while awake or a near-death experience is useful.

“Our sense it that research with DMT may yield important insights into the relationship between brain activity and consciousness, and this small study is a first step along that road.”

https://www.eurekalert.org/pub_releases/2019-11/icl-acc111819.php

Imaging of the human brain reveals constellations of activity associated with conscious and unconscious states

On By A.P.In UncategorizedLeave a comment

by Ruth Williams

The brains of people in vegetative, partially conscious, or fully conscious states have differing profiles of activity as revealed by functional magnetic resonance imaging (fMRI), according to a report today (February 6) in Science Advances. The results of the study indicate that, compared with patients lacking consciousness, the brains of healthy individuals exhibit highly dynamic and complex connectivity.

“This new study provides a substantial advance in characterizing the ‘fingerprints’ of consciousness in the brain” Anil Seth, a neuroscientist at the University of Sussex, UK, who was not involved in the project, writes in an email to The Scientist. “It opens new doors to determining conscious states—or their absence—in a range of different conditions.”

A person can lose consciousness temporarily, such as during sleep or anesthesia, or more permanently as is the case with certain brain injuries. But while unconsciousness manifests behaviorally as a failure to respond to stimuli, such behavior is not necessarily the result of unconsciousness.

Some seemingly unresponsive patients, for example, can display brain activities similar to those of fully conscious individuals when asked to imagine performing a physical task such as playing tennis. Such a mental response in the absence of physical feedback is a condition known as cognitive-motor dissociation.

Researchers are therefore attempting to build a better picture of what is happening in the human brain during consciousness and unconsciousness. In some studies, electroencephalography (EEG) recordings of the brain’s electrical activities during sleep, under anesthesia, or after brain injury have revealed patterns of brain waves associated with consciousness. But, says Jacobo Sitt of the Institute of Brain and Spinal Cord in Paris, such measurements do not provide good spatial information about brain activity. With fMRI, on the other hand, “we know where the activity is coming from.”

Sitt and colleagues performed fMRI brain scans on a total of 47 healthy individuals and 78 patients who either had unresponsive wakefulness syndrome (UWS)—a vegetative state in which the patient’s eyes open, but they never exhibit voluntary movement—or were in a minimally conscious state (MCS)—having more complex behaviors, such as the ability to follow an object with their eyes, but remaining unable to communicate thoughts or feelings. The scans were performed by an international team of collaborators at three different facilities in Paris, New York, and Liège, Belgium.

Data from the fMRI scans, which generated roughly 400 images in approximately 20 minutes for each patient, was computationally analyzed for identifiable patterns of activity. Four patterns were reproducibly detected within the data from each facility. And, for two of these patterns, the likelihood of their occurrence in a given individual’s scan depended on diagnosis.

Healthy individuals, for example, were more likely than patients to display pattern 1—characterized by high spatial complexity and interregional connectivity indicating brain-wide coordination. Patients with UWS, on the other hand, rarely displayed pattern 1, most often displaying pattern 4—characterized by low complexity and reduced interregional connectivity. Generally speaking, MCS patients fell somewhere between. The occurrence of patterns 2 and 3 were equally likely across all groups.

The team went on to analyze a second set of 11 patients at a facility in Ontario, Canada. Again the four distinct patterns were detected within the fMRI images. Six of these patients had UWS and predominantly displayed pattern 4, while the remaining five, who had cognitive-motor dissociation, had higher rates of pattern 1, supporting previous evidence for consciousness in these patients.

With such a mix of patients, facilities, scanners, and researchers, the study “had every possibility of failing,” says neuroscientist Tristan Bekinschtein of the University of Cambridge, UK, who did not participate in the research. However, the results were “brutally consistent,” he says.

Having identifiable signatures of consciousness and unconsciousness might ultimately help doctors and families make difficult decisions about continuing life support for vegetative patients, says anesthesiology researcher Anthony Hudetz of the University of Michigan who was not involved with the work. It might also provide insight into whether particular rehabilitation methods or other treatments are working.

“All that hinges on a better understanding of what goes on in the brains of these patients versus healthy or aware [people],” Hudetz says. To that end, this paper “makes a major step forward.”

A. Demertzi et al., “Human consciousness is supported by dynamic complex patterns of brain signal coordination,” Sci Adv, 5: eaat7603, 2019.

https://www.the-scientist.com/news-opinion/neural-patterns-of-consciousness-identified-65433

Superslow Brain Waves May Play a Critical Role in Consciousness

On By A.P.In Uncategorized1 Comment


Signals long thought to be “noise” appear to represent a distinct form of brain activity.

By Tanya Lewis

Every few seconds a wave of electrical activity travels through the brain, like a large swell moving through the ocean. Scientists first detected these ultraslow undulations decades ago in functional magnetic resonance imaging (fMRI) scans of people and other animals at rest—but the phenomenon was thought to be either electrical “noise” or the sum of much faster brain signals and was largely ignored.

Now a study that measured these “infraslow” (less than 0.1 hertz) brain waves in mice suggests they are a distinct type of brain activity that depends on an animal’s conscious state. But big questions remain about these waves’ origin and function.

An fMRI scan detects changes in blood flow that are assumed to be linked to neural activity. “When you put someone in a scanner, if you just look at the signal when you don’t ask the subject to do anything, it looks pretty noisy,” says Marcus Raichle, a professor of radiology and neurology at Washington University School of Medicine in St. Louis and senior author of the new study, published in April in Neuron. “All this resting-state activity brought to the forefront: What is this fMRI signal all about?”

To find out what was going on in the brain, Raichle’s team employed a combination of calcium/hemoglobin imaging, which uses fluorescent molecules to detect the activity of neurons at the cellular level, and electrophysiology, which can record signals from cells in different brain layers. They performed both measurements in awake and anesthetized mice; the awake mice were resting in tiny hammocks in a dark room.

The team found that infraslow waves traveled through the cortical layers of the awake rodents’ brains—and changed direction when the animals were anesthetized. The researchers say these waves are distinct from so-called delta waves (between 1 and 4 Hz) and other higher-frequency brain activity.

These superslow waves may be critical to how the brain functions, Raichle says. “Think of, say, waves on the water of Puget Sound. You can have very rough days where you have these big groundswells and then have whitecaps sitting on top of them,” he says. These “swells” make it easier for brain areas to become active—for “whitecaps” to form, in other words.

Other researchers praised the study’s general approach but were skeptical that it shows the infraslow waves are totally distinct from other brain activity. “I would caution against jumping to a conclusion that resting-state fMRI is measuring some other property of the brain that’s got nothing to do with the higher-frequency fluctuations between areas of the cortex,” says Elizabeth Hillman, a professor of biomedical engineering at Columbia University’s Zuckerman Institute, who was not involved in the work. Hillman published a study in 2016 finding that resting-state fMRI signals represent neural activity across a range of frequencies, not just low ones.

More studies are needed to tease apart how these different types of brain signals are related. “These kinds of patterns are very new,” Hillman notes. “We haven’t got much of a clue what they are, and figuring out what they are is really, really difficult.”

https://www.scientificamerican.com/article/superslow-brain-waves-may-play-a-critical-role-in-consciousness1/

What Blind People Experience When They Take LSD

On By A.P.In Uncategorized1 Comment

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

Possible reason why ‘magic’ mushrooms evolved

On By A.P.In UncategorizedLeave a comment

By Rafi Letzter

“Magic” mushrooms seem to have passed their genes for mind-altering substances around among distant species as a survival mechanism: By making fungus-eating insects “trip,” the bugs become less hungry — and less likely to feast on mushrooms.

That’s the upshot of a paper published Feb. 27 in the journal Evolution Letters by a team of biologists at The Ohio State University and the University of Tennessee.

The researchers studied a group of mushrooms that all produce psilocybin — the chemical agent that causes altered states of consciousness in human beings — but aren’t closely related. The scientists found that the clusters of genes that caused the ‘shrooms to fill themselves with psilocybin were very similar to one another, more similar even than clusters of genes found in closely related species of mushrooms.

That’s a sign, the researchers wrote, that the genes weren’t inherited from a common ancestor, but instead were passed directly between distant species in a phenomenon known as “horizontal gene transfer” or HGT.

HGT isn’t really one process, as the biologist Alita Burmeister explained in the journal Evolution, Medicine and Public Health in 2015. Instead, it’s the term for a group of more or less well-understood processes — like viruses picking up genes from one species and dropping them in another — that can cause groups of genes to jump between species.

However, HGT is believed to be pretty uncommon in complex, mushroom-forming fungi, turning up much more often in single-celled organisms.

When a horizontally transferred gene takes hold and spreads after landing in a new species, the paper’s authors wrote, scientists believe that’s a sign that the gene offered a solution to some crisis the organism’s old genetic code couldn’t solve on its own.

The researchers suggested — but didn’t claim to prove — that the crisis in this case was droves of insects feasting on the defenseless mushrooms. Most of the species the scientists studied grew on animal dung and rotting wood — insect-rich environments (and environments full of opportunities to perform HGT). Psilocybin, the scientists wrote, might suppress insects’ appetites or otherwise induce the bugs to stop munching quite so much mush’.

https://www.livescience.com/61877-magic-mushrooms-evolution.html

New advances in quantum artificial intelligence could lead to super-smart machines

On By A.P.In artificial intelligence, The FutureLeave a comment

by Bryan Nelson

Quantum physics has some spooky, anti-intuitive effects, but it could also be essential to how actual intuition works, at least in regards to artificial intelligence.

In a new study, researcher Vedran Dunjko and co-authors applied a quantum analysis to a field within artificial intelligence called reinforcement learning, which deals with how to program a machine to make appropriate choices to maximize a cumulative reward. The field is surprisingly complex and must take into account everything from game theory to information theory.

Dunjko and his team found that quantum effects, when applied to reinforcement learning in artificial intelligence systems, could provide quadratic improvements in learning efficiency, reports Phys.org. Exponential improvements might even be possible over short-term performance tasks. The study was published in the journal Physical Review Letters.

“This is, to our knowledge, the first work which shows that quantum improvements are possible in more general, interactive learning tasks,” explained Dunjko. “Thus, it opens up a new frontier of research in quantum machine learning.”

One of the key quantum effects in regards to learning is quantum superposition, which potentially allows a machine to perform many steps simultaneously. Such a system has vastly improved processing power, which allows it to compute more variables when making decisions.

The research is tantalizing, in part because it mirrors some theories about how biological brains might produce higher cognitive states, possibly even being related to consciousness. For instance, some scientists have proposed the idea that our brains pull off their complex calculations by making use of quantum computation.

Could quantum effects unlock consciousness in our machines? Quantum physics isn’t likely to produce HAL from “2001: A Space Odyssey” right away; the most immediate improvements in artificial intelligence will likely come in complex fields such as climate modeling or automated cars. But eventually, who knows?

You probably won’t want to be taking a joyride in an automated vehicle the moment it becomes conscious, if HAL is an example of what to expect.

“While the initial results are very encouraging, we have only begun to investigate the potential of quantum machine learning,” said Dunjko. “We plan on furthering our understanding of how quantum effects can aid in aspects of machine learning in an increasingly more general learning setting. One of the open questions we are interested in is whether quantum effects can play an instrumental role in the design of true artificial intelligence.”

http://www.mnn.com/green-tech/research-innovations/stories/quantum-artificial-intelligence-could-lead-super-smart-machines

44 year old man discovers he’s been living without 90% of his brain

On By A.P.In brain, consciousnessLeave a comment


A scan of the man missing 90% of his brain.

by Paul Ratner

What we think we know about our brains is nothing compared to what we don’t know. This fact is brought into focus by the medical mystery of a 44-year-old French father of two who found out one day that he had most of his brain missing. Instead his skull is mostly full of liquid, with almost no brain tissue left. He has a life-long condition known as hydrocephalus, commonly called “water on the brain” or “water head”. It happens when too much cerebrospinal fluid puts pressure on the brain and the brain’s cavities abnormally increase.

As Axel Cleeremans, a cognitive psychologist at the Université Libre in Brussels, who has lectured about this case, told CBC:

“He was living a normal life. He has a family. He works. His IQ was tested at the time of his complaint. This came out to be 84, which is slightly below the normal range … So, this person is not bright — but perfectly, socially apt”.

The complaint Cleeremans refers to is the original reason the man sought help – he had leg pain. Imagine that – you go to your doctor with a leg cramp and get told that you’re living without most of your brain.

The man continues to live a normal life, being a family man with a wife and kids, while working as a civil servant. All this while having 3 of his main brain cavities filled with only fluid and his brainstem and cerebellum stuck into a small space that they share with a cyst.

What can we learn from this rare case? As Cleeremans points out:

“One of the lessons is that plasticity is probably more pervasive than we thought it was… It is truly incredible that the brain can continue to function, more or less, within the normal range — with probably many fewer neurons than in a typical brain. Second lesson perhaps, if you’re interested in consciousness — that is the manner in which the biological activity of the brain produces awareness… One idea that I’m defending is the idea that awareness depends on the brain’s ability to learn.”

The French man’s story really challenges the idea that consciousness arises in one part of the brain only. Current theories hold that the part of the brain called the thalamus is responsible for our self-awareness. A man living with most of his brain missing does not fit neatly into such hypotheses.

http://bigthink.com/paul-ratner/the-medical-mystery-of-a-man-living-with-90-of-his-brain-missing?utm_source=Big+Think+Weekly+Newsletter+Subscribers&utm_campaign=709f2481ff-Newsletter_072016&utm_medium=email&utm_term=0_6d098f42ff-709f2481ff-41106061

Why you should believe in the digital afterlife

On By A.P.In consciousness, Dan Brat, The Future, The SingularityLeave a comment

by Michael Graziano

Imagine scanning your Grandma’s brain in sufficient detail to build a mental duplicate. When she passes away, the duplicate is turned on and lives in a simulated video-game universe, a digital Elysium complete with Bingo, TV soaps, and knitting needles to keep the simulacrum happy. You could talk to her by phone just like always. She could join Christmas dinner by Skype. E-Granny would think of herself as the same person that she always was, with the same memories and personality—the same consciousness—transferred to a well regulated nursing home and able to offer her wisdom to her offspring forever after.

And why stop with Granny? You could have the same afterlife for yourself in any simulated environment you like. But even if that kind of technology is possible, and even if that digital entity thought of itself as existing in continuity with your previous self, would you really be the same person?

Is it even technically possible to duplicate yourself in a computer program? The short answer is: probably, but not for a while.

Let’s examine the question carefully by considering how information is processed in the brain, and how it might be translated to a computer.

The first person to grasp the information-processing fundamentals of the brain was the great Spanish neuroscientist, Ramon Y Cajal, who won the 1906 Nobel Prize in Physiology. Before Cajal, the brain was thought to be made of microscopic strands connected in a continuous net or ‘reticulum.’ According to that theory, the brain was different from every other biological thing because it wasn’t made of separate cells. Cajal used new methods of staining brain samples to discover that the brain did have separate cells, which he called neurons. The neurons had long thin strands mixing together like spaghetti—dendrites and axons that presumably carried signals. But when he traced the strands carefully, he realized that one neuron did not grade into another. Instead, neurons contacted each other through microscopic gaps—synapses.

Cajal guessed that the synapses must regulate the flow of signals from neuron to neuron. He developed the first vision of the brain as a device that processes information, channeling signals and transforming inputs into outputs. That realization, the so-called neuron doctrine, is the foundational insight of neuroscience. The last hundred years have been dedicated more or less to working out the implications of the neuron doctrine.

It’s now possible to simulate networks of neurons on a microchip and the simulations have extraordinary computing capabilities. The principle of a neural network is that it gains complexity by combining many simple elements. One neuron takes in signals from many other neurons. Each incoming signal passes over a synapse that either excites the receiving neuron or inhibits it. The neuron’s job is to sum up the many thousands of yes and no votes that it receives every instant and compute a simple decision. If the yes votes prevail, it triggers its own signal to send on to yet other neurons. If the no votes prevail, it remains silent. That elemental computation, as trivial as it sounds, can result in organized intelligence when compounded over enough neurons connected in enough complexity.

The trick is to get the right pattern of synaptic connections between neurons. Artificial neural networks are programmed to adjust their synapses through experience. You give the network a computing task and let it try over and over. Every time it gets closer to a good performance, you give it a reward signal or an error signal that updates its synapses. Based on a few simple learning rules, each synapse changes gradually in strength. Over time, the network shapes up until it can do the task. That deep leaning, as it’s sometimes called, can result in machines that develop spooky, human-like abilities such as face recognition and voice recognition. This technology is already all around us in Siri and in Google.

But can the technology be scaled up to preserve someone’s consciousness on a computer? The human brain has about a hundred billion neurons. The connectional complexity is staggering. By some estimates, the human brain compares to the entire content of the internet. It’s only a matter of time, however, and not very much at that, before computer scientists can simulate a hundred billion neurons. Many startups and organizations, such as the Human Brain project in Europe, are working full-tilt toward that goal. The advent of quantum computing will speed up the process considerably. But even when we reach that threshold where we are able to create a network of a hundred billion artificial neurons, how do we copy your special pattern of connectivity?

No existing scanner can measure the pattern of connectivity among your neurons, or connectome, as it’s called. MRI machines scan at about a millimeter resolution, whereas synapses are only a few microns across. We could kill you and cut up your brain into microscopically thin sections. Then we could try to trace the spaghetti tangle of dendrites, axons, and their synapses. But even that less-than-enticing technology is not yet scalable. Scientists like Sebastian Seung have plotted the connectome in a small piece of a mouse brain, but we are decades away, at least, from technology that could capture the connectome of the human brain.

Assuming we are one day able to scan your brain and extract your complete connectome, we’ll hit the next hurdle. In an artificial neural network, all the neurons are identical. They vary only in the strength of their synaptic interconnections. That regularity is a convenient engineering approach to building a machine. In the real brain, however, every neuron is different. To give a simple example, some neurons have thick, insulated cables that send information at a fast rate. You find these neurons in parts of the brain where timing is critical. Other neurons sprout thinner cables and transmit signals at a slower rate. Some neurons don’t even fire off signals—they work by a subtler, sub-threshold change in electrical activity. All of these neurons have different temporal dynamics.

The brain also uses hundreds of different kinds of synapses. As I noted above, a synapse is a microscopic gap between neurons. When neuron A is active, the electrical signal triggers a spray of chemicals—neurotransmitters—which cross the synapse and are picked up by chemical receptors on neuron B. Different synapses use different neurotransmitters, which have wildly different effects on the receiving neuron, and are re-absorbed after use at different rates. These subtleties matter. The smallest change to the system can have profound consequences. For example, Prozac works on people’s moods because it subtly adjusts the way particular neurotransmitters are reabsorbed after being released into synapses.

Although Cajal didn’t realize it, some neurons actually do connect directly, membrane to membrane, without a synaptic space between. These connections, called gap junctions, work more quickly than the regular kind and seem to be important in synchronizing the activity across many neurons.

Other neurons act like a gland. Instead of sending a precise signal to specific target neurons, they release a chemical soup that spreads and affects a larger area of the brain over a longer time.

I could go on with the biological complexity. These are just a few examples.

A student of artificial intelligence might argue that these complexities don’t matter. You can build an intelligent machine with simpler, more standard elements, ignoring the riot of biological complexity. And that is probably true. But there is a difference between building artificial intelligence and recreating a specific person’s mind.

If you want a copy of your brain, you will need to copy its quirks and complexities, which define the specific way you think. A tiny maladjustment in any of these details can result in epilepsy, hallucinations, delusions, depression, anxiety, or just plain unconsciousness. The connectome by itself is not enough. If your scan could determine only which neurons are connected to which others, and you re-created that pattern in a computer, there’s no telling what Frankensteinian, ruined, crippled mind you would create.

To copy a person’s mind, you wouldn’t need to scan anywhere near the level of individual atoms. But you would need a scanning device that can capture what kind of neuron, what kind of synapse, how large or active of a synapse, what kind of neurotransmitter, how rapidly the neurotransmitter is being synthesized and how rapidly it can be reabsorbed. Is that impossible? No. But it starts to sound like the tech is centuries in the future rather than just around the corner.

Even if we get there quicker, there is still another hurdle. Let’s suppose we have the technology to make a simulation of your brain. Is it truly conscious, or is it merely a computer crunching numbers in imitation of your behavior?

A half-dozen major scientific theories of consciousness have been proposed. In all of them, if you could simulate a brain on a computer, the simulation would be as conscious as you are. In the Attention Schema Theory, consciousness depends on the brain computing a specific kind of self-descriptive model. Since this explanation of consciousness depends on computation and information, it would translate directly to any hardware including an artificial one.

In another approach, the Global Workspace Theory, consciousness ignites when information is combined and shared globally around the brain. Again, the process is entirely programmable. Build that kind of global processing network, and it will be conscious.

In yet another theory, the Integrated Information Theory, consciousness is a side product of information. Any computing device that has a sufficient density of information, even an artificial device, is conscious.

Many other scientific theories of consciousness have been proposed, beyond the three mentioned here. They are all different from each other and nobody yet knows which one is correct. But in every theory grounded in neuroscience, a computer-simulated brain would be conscious. In some mystical theories and theories that depend on a loose analogy to quantum mechanics, consciousness would be more difficult to create artificially. But as a neuroscientist, I am confident that if we ever could scan a person’s brain in detail and simulate that architecture on a computer, then the simulation would have a conscious experience. It would have the memories, personality, feelings, and intelligence of the original.

And yet, that doesn’t mean we’re out of the woods. Humans are not brains in vats. Our cognitive and emotional experience depends on a brain-body system embedded in a larger environment. This relationship between brain function and the surrounding world is sometimes called “embodied cognition.” The next task therefore is to simulate a realistic body and a realistic world in which to embed the simulated brain. In modern video games, the bodies are not exactly realistic. They don’t have all the right muscles, the flexibility of skin, or the fluidity of movement. Even though some of them come close, you wouldn’t want to live forever in a World of Warcraft skin. But the truth is, a body and world are the easiest components to simulate. We already have the technology. It’s just a matter of allocating enough processing power.

In my lab, a few years ago, we simulated a human arm. We included the bone structure, all the fifty or so muscles, the slow twitch and fast twitch fibers, the tendons, the viscosity, the forces and inertia. We even included the touch receptors, the stretch receptors, and the pain receptors. We had a working human arm in digital format on a computer. It took a lot of computing power, and on our tiny machines it couldn’t run in real time. But with a little more computational firepower and a lot bigger research team we could have simulated a complete human body in a realistic world.

Let’s presume that at some future time we have all the technological pieces in place. When you’re close to death we scan your details and fire up your simulation. Something wakes up with the same memories and personality as you. It finds itself in a familiar world. The rendering is not perfect, but it’s pretty good. Odors probably don’t work quite the same. The fine-grained details are missing. You live in a simulated New York City with crowds of fellow dead people but no rats or dirt. Or maybe you live in a rural setting where the grass feels like Astroturf. Or you live on the beach in the sun, and every year an upgrade makes the ocean spray seem a little less fake. There’s no disease. No aging. No injury. No death unless the operating system crashes. You can interact with the world of the living the same way you do now, on a smart phone or by email. You stay in touch with living friends and family, follow the latest elections, watch the summer blockbusters. Maybe you still have a job in the real world as a lecturer or a board director or a comedy writer. It’s like you’ve gone to another universe but still have contact with the old one.

But is it you? Did you cheat death, or merely replace yourself with a creepy copy?

I can’t pretend to have a definitive answer to this philosophical question. Maybe it’s a matter of opinion rather than anything testable or verifiable. To many people, uploading is simply not an afterlife. No matter how accurate the simulation, it wouldn’t be you. It would be a spooky fake.

My own perspective borrows from a basic concept in topology. Imagine a branching Y. You’re born at the bottom of the Y and your lifeline progresses up the stalk. The branch point is the moment your brain is scanned and the simulation has begun. Now there are two of you, a digital one (let’s say the left branch) and a biological one (the right branch). They both inherit the memories, personality, and identity of the stalk. They both think they’re you. Psychologically, they’re equally real, equally valid. Once the simulation is fired up, the branches begin to diverge. The left branch accumulates new experiences in a digital world. The right branch follows a different set of experiences in the physical world.

Is it all one person, or two people, or a real person and a fake one? All of those and none of those. It’s a Y.

The stalk of the Y, the part from before the split, gains immortality. It lives on in the digital you, just like your past self lives on in your present self. The right hand branch, the post-split biological branch, is doomed to die. That’s the part that feels gypped by the technology.

So let’s assume that those of us who live in biological bodies get over this injustice, and in a century or three we invent a digital afterlife. What could possibly go wrong?

Well, for one, there are limited resources. Simulating a brain is computationally expensive. As I noted before, by some estimates the amount of information in the entire internet at the present time is approximately the same as in a single human brain. Now imagine the resources required to simulate the brains of millions or billions of dead people. It’s possible that some future technology will allow for unlimited RAM and we’ll all get free service. The same way we’re arguing about health care now, future activists will chant, “The afterlife is a right, not a privilege!” But it’s more likely that a digital afterlife will be a gated community and somebody will have to choose who gets in. Is it the rich and politically connected who live on? Is it Trump? Is it biased toward one ethnicity? Do you get in for being a Nobel laureate, or for being a suicide bomber in somebody’s hideous war? Just think how coercive religion can be when it peddles the promise of an invisible afterlife that can’t be confirmed. Now imagine how much more coercive a demagogue would be if he could dangle the reward of an actual, verifiable afterlife. The whole thing is an ethical nightmare.

And yet I remain optimistic. Our species advances every time we develop a new way to share information. The invention of writing jump-started our advanced civilizations. The computer revolution and the internet are all about sharing information. Think about the quantum leap that might occur if instead of preserving words and pictures, we could preserve people’s actual minds for future generations. We could accumulate skill and wisdom like never before. Imagine a future in which your biological life is more like a larval stage. You grow up, learn skills and good judgment along the way, and then are inducted into an indefinite digital existence where you contribute to stability and knowledge. When all the ethical confusion settles, the benefits may be immense. No wonder people like Ray Kurzweil refer to this kind of technological advance as a singularity. We can’t even imagine how our civilization will look on the other side of that change.

http://www.theatlantic.com/science/archive/2016/07/what-a-digital-afterlife-would-be-like/491105/

Thanks to Dan Brat for bringing this to the It’s Interesting community.

How LSD Makes Your Brain One With The Universe

On By A.P.In brain, Drugs, hallucination, hallucinations, LSD, lysergic acid diethylamaide, Psilocybin2 Comments

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