Chapter 2. Cells and Structures: The Anatomy of the Nervous System
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Rachel Ehrenberg Patterns of neural circuitry in the brain's frontal and parietal lobes can be used to distinguish individuals on the basis of their brain scans. Our brains are wired in such distinctive ways that an individual can be identified on the basis of brain-scan images alone, neuroscientists report. In a study published in Nature Neuroscience1 on 12 October, researchers studied scans of brain activity in 126 adults who had been asked to perform various cognitive tasks, such as memory and language tests. The data were gathered by the Human Connectome Project, a US$40-million international effort that aims to map out the highways of neural brain activity in 1200 people. To study connectivity patterns, researchers divided the brain scans into 268 regions or nodes (each about two centimetres cubed and comprising hundreds of millions of neurons). They looked at areas that showed synchronized activity, rather like discerning which instruments are playing together in a 268-piece orchestra, says Emily Finn, a co-author of the study and a neuroscience PhD student at Yale University in New Haven, Connecticut. In some regions of the brain — such as those that involve networks controlling basic vision and motor skills — most people’s neural circuitry connects up in similar ways, the team found. But patterns of connectivity in other brain regions, such as the frontal lobes, seem to differ between individuals. The researchers were able to match the scan of a given individual's brain activity during one imaging session to the same person’s brain scan taken at another time — even when that person was engaged in a different task in each session. © 2015 Nature Publishing Group
Keyword: Brain imaging
Link ID: 21506 - Posted: 10.13.2015
By KENNETH D. MILLER SOME hominid along the evolutionary path to humans was probably the first animal with the cognitive ability to understand that it would someday die. To be human is to cope with this knowledge. Many have been consoled by the religious promise of life beyond this world, but some have been seduced by the hope that they can escape death in this world. Such hopes, from Ponce de León’s quest to find a fountain of youth to the present vogue for cryogenic preservation, inevitably prove false. In recent times it has become appealing to believe that your dead brain might be preserved sufficiently by freezing so that some future civilization could bring your mind back to life. Assuming that no future scientists will reverse death, the hope is that they could analyze your brain’s structure and use this to recreate a functioning mind, whether in engineered living tissue or in a computer with a robotic body. By functioning, I mean thinking, feeling, talking, seeing, hearing, learning, remembering, acting. Your mind would wake up, much as it wakes up after a night’s sleep, with your own memories, feelings and patterns of thought, and continue on into the world. I am a theoretical neuroscientist. I study models of brain circuits, precisely the sort of models that would be needed to try to reconstruct or emulate a functioning brain from a detailed knowledge of its structure. I don’t in principle see any reason that what I’ve described could not someday, in the very far future, be achieved (though it’s an active field of philosophical debate). But to accomplish this, these future scientists would need to know details of staggering complexity about the brain’s structure, details quite likely far beyond what any method today could preserve in a dead brain. © 2015 The New York Times Company
Fragment of rat brain simulated in supercomputer Moheb Costandi A controversial European neuroscience project that aims to simulate the human brain in a supercomputer has published its first major result: a digital imitation of circuitry in a sandgrain-sized chunk of rat brain. The work models some 31,000 virtual brain cells connected by roughly 37 million synapses. The goal of the Blue Brain Project, which launched in 2005 and is led by neurobiologist Henry Markram of the Swiss Federal Institute of Technology in Lausanne (EPFL), is to build a biologically-detailed computer simulation of the brain based on experimental data about neurons' 3D shapes, their electrical properties, and the ion channels and other proteins that different cell types typically produce (see ‘Brain in a box’). Such a simulation would provide deep insights into the way the brain works, says Markram. But other neuroscientists have argued that it will reveal no more about the brain’s workings than do simpler, more abstract simulations of neural circuitry — while sucking up a great deal of computing power and resources. The initiative has links with the Human Brain Project, a €1-billion (US$1.1-billion), decade-long initiative which Markram helped persuade the European Commission to fund, and which also aims to advance supercomputer brain simulation. It launched in 2013, with Markram as co-leader, although this March its leadership was switched and its scientific programme altered, after criticism of the way it was being managed. © 2015 Nature Publishing Group
Keyword: Brain imaging
Link ID: 21494 - Posted: 10.09.2015
By Emily Underwood WASHINGTON, D.C.—As part of President Barack Obama’s high-profile initiative to study the brain, the Kavli Foundation and several university partners today announced $100 million in new funding for neuroscience research, including three new institutes at universities in Maryland, New York, and California. Each of the institutes will receive a $20 million endowment, provided equally by their universities and the foundation, along with start-up funding to pursue projects in areas such as brain plasticity and tool development. The new funding, geared at providing stable support for high-risk, interdisciplinary research, exceeds the original commitment of $40 million that the Kavli Foundation made to the national Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative, when it was first launched by President Obama in 2013. The funds are also unrestricted, allowing each institute to determine which projects to pursue. “That’s the most precious money any scientist can have,” Robert Conn, president and CEO of The Kavli Foundation, noted at a meeting today on Capitol Hill. Neuroscientist Loren Frank, who will serve as co-director at the new institute at the University of California, San Francisco, says the funds will allow his lab to explore fundamental questions such as how the brain can maintain its function despite constant change, and to form interdisciplinary partnerships with labs such as the Lawrence Livermore National Laboratory. The other two sites creating new institutes are Johns Hopkins University in Baltimore, Maryland, and Rockefeller University in New York City. In addition, Kavli announced a $40 million boost for four of its existing neuroscience institutes, located at Yale University, UC San Diego, Columbia University, and the Norwegian University of Science and Technology. © 2015 American Association for the Advancement of Science.
Keyword: Brain imaging
Link ID: 21471 - Posted: 10.03.2015
Sara Reardon The brain’s wiring patterns can shed light on a person’s positive and negative traits, researchers report in Nature Neuroscience1. The finding, published on 28 September, is the first from the Human Connectome Project (HCP), an international effort to map active connections between neurons in different parts of the brain. The HCP, which launched in 2010 at a cost of US$40 million, seeks to scan the brain networks, or connectomes, of 1,200 adults. Among its goals is to chart the networks that are active when the brain is idle; these are thought to keep the different parts of the brain connected in case they need to perform a task. In April, a branch of the project led by one of the HCP's co-chairs, biomedical engineer Stephen Smith at the University of Oxford, UK, released a database of resting-state connectomes from about 460 people between 22 and 35 years old. Each brain scan is supplemented by information on approximately 280 traits, such as the person's age, whether they have a history of drug use, their socioeconomic status and personality traits, and their performance on various intelligence tests. Smith and his colleagues ran a massive computer analysis to look at how these traits varied among the volunteers, and how the traits correlated with different brain connectivity patterns. The team was surprised to find a single, stark difference in the way brains were connected. People with more 'positive' variables, such as more education, better physical endurance and above-average performance on memory tests, shared the same patterns. Their brains seemed to be more strongly connected than those of people with 'negative' traits such as smoking, aggressive behaviour or a family history of alcohol abuse. © 2015 Nature Publishing Group,
James Gorman Turning certain brain cells on and off with light — a technique called optogenetics — is one of the most important tools in neuroscience. It allows scientists to test basic ideas about how brains work. But because waves of visible light don’t penetrate living tissue well, the technique requires the insertion of a conduit for the light into the brain— a very thin fiber optic cable. For the first time, researchers say, they have done the same with ultrasound, opening the way to a noninvasive way to probe the functions of neurons. They call the technique sonogenetics. They achieved this in a microscopic worm, a creature so simple that it doesn’t have a brain. But it does have neurons, which have a great deal in common with the neurons in more complex animals that make up the brain and nervous system. If the technique works in more complex animals, it would mean a noninvasive way to do basic research, and perhaps even treat brain circuits. “Previous studies have shown if you use ultrasound, you can manipulate the nervous system,” said Sreekanth H. Chalasani of the Salk Institute in San Diego and senior author of a recent report in Nature Communications that describes the research. But, he said, nobody had shown that, with genetic modifications, specific neurons could be targeted. “It’s going to be a viable technique,” said William Tyler, a neuroscientist at Arizona State University, who said the ability to zero in on one neuron or a group of neurons without having to insert anything into the body was “unparalleled.” © 2015 The New York Times Company
Keyword: Brain imaging
Link ID: 21453 - Posted: 09.28.2015
Ellen Brait in New York Mind reading might not be as far-fetched as many people believe, says a study published by researchers at the University of Washington. Their research, published in PLOS One on Wednesday, demonstrated “that a non-invasive brain-to-brain interface (BBI) can be used to allow one human to guess what is on the mind of another human”. With only the use of brainwaves and a specifically designed computer, they examined the potential for exchanging basic information without saying a word. “We are actually still at the beginning of the field of interface technology and we are just mapping out the landscape so every single step is a step that opens up some new possibilities,” said lead author Andrea Stocco, an assistant professor of psychology and a researcher at UW’s Institute for Learning and Brain Sciences. The experiment had five pairs of men and women between the ages of 19 and 39 play a game similar to 20 questions. Each group had a “respondent”, who picked an object from lists provided, and an “inquirer”, who tried to guess the object by asking yes or no questions. They were placed in different rooms, approximately one mile apart. After a question was picked, it appeared on the respondent’s computer screen. They had two seconds to look at the question and one second to choose an answer. To do so, they looked at one of two flashing lights that were labeled yes or no. Each answer generated slightly different types of neural activity. © 2015 Guardian News and Media Limited
Claudia Dreifus Cornelia Bargmann, a neurobiologist at Rockefeller University in New York, studies how genes interact with neurons to create behavior. Two years ago, President Obama named Dr. Bargmann, who is known as Cori, a co-chairwoman of the advisory commission for the Brain Initiative, which he has described as “giving scientists the tools they need to get a dynamic picture of the brain in action.” I spoke with Dr. Bargmann, 53, for two hours at the Manhattan apartment she shares with her husband, Dr. Richard Axel, a neuroscientist at Columbia University. Our interview has been edited and condensed. Q. As an M.I.T. graduate student, you made a discovery that ultimately led to the breast cancer drug Herceptin. How did it happen? A. What I did was discover a mutated gene that triggered an obscure cancer in rats. Afterwards, it was discovered — by others — that this same gene is also altered in human breast cancers. Since our work in the rat cancer showed that the immune system could attack the product of this gene, Genentech developed a way to deploy the immune system. That’s Herceptin. It is an antibody against the gene that sits on the surface of a cancer cell. It can attack the cancer cell growing because of that gene. Currently, you spend your time trying to understand the nervous system of a tiny worm, C. elegans. Why do you study this worm? Well, the reason is this: Understanding the human brain is a great and complex problem. To solve the brain’s mysteries, you often have to break a problem down to a simpler form. Your brain has 86 billion nerve cells, and in any mental process, millions of them are engaged. Information is sweeping across these millions of neurons. With present technology, it’s impossible to study that process at the level of detail and speed you would want. © 2015 The New York Times Company
Helen Shen Neuroscientists have used ultrasound to stimulate individual brain cells in a worm, and hope that the technique — which they call ‘sonogenetics’ — might be adapted to switch on neurons in mice and larger animals. The technique relies on touch-sensitive ‘channel’ proteins, which can be added to particular brain cells through genetic engineering. The channels open when hit by an ultrasonic pulse, which allows ions to flood into a neuron and so causes it to turn on. Ultrasound could be a less-invasive way for researchers to stimulate specific cell types or individual neurons, rather than using implanted electrodes or fibre-optic cables, says neurobiologist Sreekanth Chalasani, at the Salk Institute for Biological Studies in La Jolla, California, who led the study reported today in Nature Communications1. “Our hope is to create a toolbox of different channels that would each respond to different intensities of ultrasound,” he says. "It's a cool new idea, and they show that this could really be feasible," says Jon Pierce-Shimomura, a neuroscientist who studies the nematode Caenorhabditis elegans at the University of Texas at Austin. “This could open a whole new way for manipulating the nervous system non-invasively through genetically encodable tools.” © 2015 Nature Publishing Group,
Keyword: Brain imaging
Link ID: 21417 - Posted: 09.16.2015
by Julia Belluz When neuroscientists stuck a dead salmon in an fMRI machine and watched its brain light up, they knew they had a problem. It wasn't that there was a dead fish in their expensive imaging machine; they'd put it there on purpose, after all. It was that the medical device seemed to be giving these researchers impossible results. Dead fish should not have active brains. The lit of brain of a dead salmon — a cautionary neuroscience tale. (University of California Santa Barbara research poster) The researchers shared their findings in 2009 as a cautionary tale: If you don't run the proper statistical tests on your neuroscience data, you can come up with any number of implausible conclusions — even emotional reactions from a dead fish. In the 1990s, neuroscientists started using the massive, round fMRI (or functional magnetic resonance imaging) machines to peer into their subjects' brains. But since then, the field has suffered from a rash of false positive results and studies that lack enough statistical power — the likelihood of finding a real result when it exists — to deliver insights about the brain. When other scientists try to reproduce the results of original studies, they too often fail. Without better methods, it'll be difficult to develop new treatments for brain disorders and diseases like Alzheimer's and depression — let alone learn anything useful about our most mysterious organ. © 2015 Vox Media, Inc
Keyword: Brain imaging
Link ID: 21292 - Posted: 08.13.2015
Alison Abbott This is the crackle of neural activity that allows a fruit-fly (Drosophila melanogaster) larva to crawl backwards: a flash in the brain and a surge that undulates through the nervous system from the top of the larva’s tiny body to the bottom. When the larva moves forwards, the surge flows the other way. The video — captured almost at the resolution of single neurons — demonstrates the latest development in a technique to film neural activity throughout an entire organism. The original method was invented by Philipp Keller and Misha Ahrens at the Howard Hughes Medical Institute's Janelia Research Campus in Ashburn, Virginia. The researchers genetically modify neurons so that each cell fluoresces when it fires; they then use innovative microscopy that involves firing sheets of light into the brain to record that activity. In 2013, the researchers produced a video of neural activity across the brain of a (transparent) zebrafish larva1. The fruit-fly larva that is mapped in the latest film, published in Nature Communications on 11 August2, is more complicated. The video shows neural activity not just in the brain, but throughout the entire central nervous system (CNS), including the fruit-fly equivalent of a mammalian spinal cord. And unlike the zebrafish, the fruit fly's nervous system is not completely transparent, which makes it harder to image. The researchers stripped the CNS from the larva’s body to examine it. For up to an hour after removal, the CNS continues to spontaneously fire the coordinated patterns of activity that typically drive crawling (and other behaviours). © 2015 Nature Publishing Group
Keyword: Brain imaging
Link ID: 21291 - Posted: 08.12.2015
By SAM ROBERTS Dr. Louis Sokoloff, who pioneered the PET scan technique for measuring human brain function and diagnosing disorders, died on July 30 in Washington. He was 93. His death was confirmed by his daughter, Ann, his only immediate survivor. Dr. Sokoloff, who headed the brain metabolism laboratory at the National Institute of Mental Health in Bethesda, Md., received the Albert Lasker Clinical Medical Research Award in 1981 for his role in developing the vivid color images that map brain function. The technique measures the metabolism of its primary fuel, glucose, through a radioactive substitute that, unlike glucose, lingers long enough to undergo chemical analysis. “The Sokoloff method,” the Lasker Foundation said, “has facilitated the diagnosis, understanding and possible future treatment of such disorders of the brain as schizophrenia, epilepsy, brain changes due to drug addiction and senile dementia.” As early as the mid-1940s, when he was practicing psychotherapy in the Army as chief of neuropsychiatry at Camp Lee, Va. (now Fort Lee), he believed there was a physiological and biochemical component to mental illness. “Of course, the psychoanalysts said it had nothing to do with the brain; it had to do with the mind — it could have been anywhere, it could have been in the big toe,” he said in an interview in 2005, shortly after he officially retired from the institute. “For me, mind and brain were inextricably linked,” he wrote in an autobiographical essay published in 1996, “a linkage that was irrelevant to psychiatry at that time.” © 2015 The New York Times Company
Keyword: Brain imaging
Link ID: 21273 - Posted: 08.08.2015
A dipstick inserted into the brain can check its energy levels, just like checking oil levels in a car. The dipstick is already available and can save lives, according to some neuroscientists. “The goal is to save brain tissue,” says Elham Rostami of the Karolinska Institute in Stockholm, Sweden. Last month, Rostami and 47 others published guidelines about how and when to use the technique, known as brain microdialysis, in the hope of encouraging more hospitals to adopt it. The approach involves inserting a slim, 1-centimetre-long probe directly into the brain. It measures levels of chemicals in the fluid that bathes brain cells, including glucose, the brain’s main energy source. When used to monitor the brains of people in intensive care after a stroke or head injury, it warns doctors if glucose starts to dip – which can cause brain damage. The probe can theoretically monitor almost any molecule, but Rostami says the most useful parameters are glucose, which shows if there is a good blood supply, and lactate and pyruvate, two metabolites that indicate if brain cells are using the glucose to release energy. Although widely available, the device has so far mainly been used as a research tool rather than to guide treatment. Rostami believes her use of the probe helped save a woman’s life last year. The woman was in intensive care after a stroke involving bleeding on the surface of her brain. The probe revealed that although the bleeding had stopped, the woman’s brain glucose levels had fallen, probably caused by other blood vessels constricting. © Copyright Reed Business Information Ltd.
Laura Sanders A type of brain cell formerly known for its supporting role has landed a glamorous new job. Astrocytes, a type of glial cell known to feed, clean and guide the growth of their flashier nerve cell neighbors, also help nerve cells send electrical transmissions, scientists report in the Aug. 5 Journal of Neuroscience. The results are the latest in scientists’ efforts to uncover the mysterious and important ways in which cells other than nerve cells keep the nervous system humming. Astrocytes deliver nutrients to nerve cells, flush waste out of the brain (SN: 9/22/12) and even help control appetite (SN: 6/28/14). The latest study suggests that these star-shaped cells also help electrical messages move along certain nerve cells’ message-sending axons, a job already attributed to other glial cells called oligodendrocytes and Schwann cells. Courtney Sobieski of Washington University School of Medicine in St. Louis and colleagues grew individual rat nerve cells in a single dish that contained patches of astrocytes. Some nerve cells grew on the patches; others did not. The nerve cells deprived of astrocyte contact showed signs of sluggishness. The researchers think that astrocytes guide nerve cell growth in a way that enables the nerve cells to later fire off quick and precise messages. It’s not clear how the astrocytes do that, but the results suggest that proximity is the key: Astrocytes needed to be close to the nerve cell to help messages move. © Society for Science & the Public 2000 - 2015
Alison Abbott Six years might seem like a long time to spend piecing together the structure of a scrap of tissue vastly smaller than a bead of sweat. But that is how long it has taken a team led by cell biologist Jeff Lichtman from Harvard University in Cambridge, Massachusetts, to digitally reconstruct a tiny cube of mouse brain tissue. The resulting three-dimensional map1 is the first complete reconstruction of a piece of tissue in the mammalian neocortex, the most recently evolved region of the brain. Covering just 1,500 cubic microns, it is still a far cry from reconstructing all 100 billion or so cells that make up the entire human brain. But Christof Koch, president of the Allen Institute for Brain Science in Seattle, Washington, notes that the various technologies involved will speed up “tremendously” over the next decade: “I would call this a very exciting promissory note,” he says. Lichtman’s team already has its eyes on a much bigger challenge: reconstructing a cubic millimetre of rodent neocortex — a piece of tissue around 600,000 times larger than the present achievement. The researchers will be doing this as part of a consortium that earlier this month received preliminary approval for major funding by the US government agency IARPA (Intelligence Advanced Research Projects Activity), which promotes high-risk, high pay-off research. The goal of the consortium, based at Harvard and at the Massachusetts Institute of Technology (MIT) in Cambridge, is to map the function as well as the anatomy of this tiny brain volume, while also working out how it computes information as an animal learns. © 2015 Nature Publishing Group,
Keyword: Brain imaging
Link ID: 21249 - Posted: 08.01.2015
Jon Hamilton Lihong Wang creates the sort of medical technology you'd expect to find on the starship Enterprise. Wang, a professor of biomedical engineering at Washington University in St. Louis, has already helped develop instruments that can detect individual cancer cells in the bloodstream and oxygen consumption deep within the body. He has also created a camera that shoots at 100 billion frames a second, fast enough to freeze an object traveling at the speed of light. "It's really about turning some of these ideas that we thought were science fiction into fact," says Richard Conroy, who directs the Division of Applied Science & Technology at the National Institute of Biomedical Imaging and Bioengineering. Wang's ultimate goal is to use a combination of light and sound to solve the mysteries of the human brain. The brain is a "magical black box we still don't understand," he says. Wang describes himself as a toolmaker. And when President Obama unveiled his BRAIN initiative a couple of years ago to accelerate efforts to understand how we think and learn and remember, Wang realized that brain researchers really needed a tool he'd been working on for years. "We want to conquer the brain," Wang says. "But even for a mouse brain, which is only a few millimeters thick, we really don't have a technique that allows us to see throughout the whole brain." Current brain-imaging techniques such as functional MRI or PET scans all have drawbacks. They're slow, or not sharp enough, or they can only see things near the surface. So Wang has been developing another approach, one he believes will be fast enough to monitor brain activity in real time and sharp enough to reveal an individual brain cell. © 2015 NPR
Keyword: Brain imaging
Link ID: 21226 - Posted: 07.27.2015
A study showed that scientists can wirelessly determine the path a mouse walks with a press of a button. Researchers at the Washington University School of Medicine, St. Louis, and University of Illinois, Urbana-Champaign, created a remote controlled, next-generation tissue implant that allows neuroscientists to inject drugs and shine lights on neurons deep inside the brains of mice. The revolutionary device is described online in the journal Cell. Its development was partially funded by the National Institutes of Health. “It unplugs a world of possibilities for scientists to learn how brain circuits work in a more natural setting.” said Michael R. Bruchas, Ph.D., associate professor of anesthesiology and neurobiology at Washington University School of Medicine and a senior author of the study. The Bruchas lab studies circuits that control a variety of disorders including stress, depression, addiction, and pain. Typically, scientists who study these circuits have to choose between injecting drugs through bulky metal tubes and delivering lights through fiber optic cables. Both options require surgery that can damage parts of the brain and introduce experimental conditions that hinder animals’ natural movements. To address these issues, Jae-Woong Jeong, Ph.D., a bioengineer formerly at the University of Illinois at Urbana-Champaign, worked with Jordan G. McCall, Ph.D., a graduate student in the Bruchas lab, to construct a remote controlled, optofluidic implant. The device is made out of soft materials that are a tenth the diameter of a human hair and can simultaneously deliver drugs and lights.
Keyword: Brain imaging
Link ID: 21184 - Posted: 07.18.2015
By Ariel Sabar In televised remarks from the East Room of the White House on April 2, 2013, President Obama unveiled a scientific mission as grand as the Apollo program. The goal wasn’t outer space, but a frontier every bit as bewitching: the human brain. Obama challenged the nation’s “most imaginative and effective researchers” to map in real time the flickerings of all 100 billion nerve cells in the brain of a living person, a voyage deep into the neural cosmos never attempted at so fine a scale. A panoramic view of electric pulses pinballing across the brain could lead to major new understandings of how we think, remember and learn, and how ills from autism to Alzheimer’s rewire our mental circuitry. “We have a chance to improve the lives of not just millions,” the president said, “but billions of people on this planet.” The next month, six miles from the White House, a Harvard professor named Florian Engert grabbed a mic and, in front of the nation’s top neuroscientists, declared Obama’s effort essentially futile. “We have those data now,” said Engert, who, in a room full of professorial blazers and cardigans, was wearing a muscle shirt that afforded ample views of his bulging biceps. “We discovered they’re actually not all that useful.” (“I think whole-brain imaging is just a bunch of bull----,” is how he put it to me later.) To the other researchers, he must have sounded like a traitor. Engert, who is 48, was basically the first person on the planet to observe a brain in the wall-to-wall way Obama envisioned. He and his colleagues had done it with a sci-fi-worthy experiment that recorded every blip of brain activity in a transparent baby zebrafish, a landmark feat published just a year earlier in the marquee scientific journal Nature. For Engert to suggest that the president’s brain quest was bunk was a bit like John Glenn returning from orbit and telling JFK not to bother with a lunar landing.
Keyword: Brain imaging
Link ID: 21119 - Posted: 07.02.2015
By GARY MARCUS SCIENCE has a poor track record when it comes to comparing our brains to the technology of the day. Descartes thought that the brain was a kind of hydraulic pump, propelling the spirits of the nervous system through the body. Freud compared the brain to a steam engine. The neuroscientist Karl Pribram likened it to a holographic storage device. Many neuroscientists today would add to this list of failed comparisons the idea that the brain is a computer — just another analogy without a lot of substance. Some of them actively deny that there is much useful in the idea; most simply ignore it. Often, when scientists resist the idea of the brain as a computer, they have a particular target in mind, which you might call the serial, stored-program machine. Here, a program (or “app”) is loaded into a computer’s memory, and an algorithm, or recipe, is executed step by step. (Calculate this, then calculate that, then compare what you found in the first step with what you found in the second, etc.) But humans don’t download apps to their brains, the critics note, and the brain’s nerve cells are too slow and variable to be a good match for the transistors and logic gates that we use in modern computers. If the brain is not a serial algorithm-crunching machine, though, what is it? A lot of neuroscientists are inclined to disregard the big picture, focusing instead on understanding narrow, measurable phenomena (like the mechanics of how calcium ions are trafficked through a single neuron), without addressing the larger conceptual question of what it is that the brain does. This approach is misguided. Too many scientists have given up on the computer analogy, and far too little has been offered in its place. In my view, the analogy is due for a rethink. To begin with, all the standard arguments about why the brain might not be a computer are pretty weak. Take the argument that “brains are parallel, but computers are serial.” Critics are right to note that virtually every time a human does anything, many different parts of the brain are engaged; that’s parallel, not serial. © 2015 The New York Times Company
Keyword: Brain imaging
Link ID: 21099 - Posted: 06.27.2015
By Nellie Bowles One recent Friday night, at a software-development firm’s warehouse in San Francisco, Mikey Siegel called to order the hundred and fifty or so meditators, video gamers, and technocrats who had gathered for one of the city’s biweekly Consciousness Hacking meet-ups. Siegel, the primary organizer of the event and the founder of a Santa Cruz–based biofeedback startup called Bio Fluent, asked the crowd, men and women of widely varied ages, to go around the room introducing themselves in three words. Everyone laughed, but took the task seriously. The introductions moved quickly through the room in a brisk beat: “Me Technological Cartoon” “Heather Curious About Brains” “Neuromore Singularity Atom Here” “Dan Thoughtful Helpful Software” “Harry Self-Modification Exploration” “David Psychiatrist Technological Retarded Curious” “Jordan Moving Meditation Butts” “Juliana Joel’s Aunt” “Ben Existence Existence Existence” “Zohara Chocolate Maker Meditation Awareness” “Lila Awake Empath Warrior” San Francisco’s Consciousness Hacking meet-ups are an opportunity for engineers, entrepreneurs, and enthusiasts to test the fleet of still experimental self-examination technologies emerging largely from Silicon Valley. The region’s tech community is a body culture, obsessed with monitoring and perfecting its food (Soylent), fitness (Fitbit), and physiology (23andMe). As brain-wave technologies get cheaper and more popular, some company founders hope that consumers, who seem to be acclimating to devices like the increasingly ubiquitous Fitbit, will consider other, more cumbersome devices and procedures. Consciousness Hackers are a kind of self-selected early market-research group. Tonight, that was especially clear.