Chapter 2. Functional Neuroanatomy: The Cells and Structure of the Nervous System

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Laura Sanders A new view of the human brain shows its cellular residents in all their wild and weird glory. The map, drawn from a tiny piece of a woman’s brain, charts the varied shapes of 50,000 cells and 130 million connections between them. This intricate map, named H01 for “human sample 1,” represents a milestone in scientists’ quest to provide ever more detailed descriptions of a brain (SN: 2/7/14). “It’s absolutely beautiful,” says neuroscientist Clay Reid at the Allen Institute for Brain Science in Seattle. “In the best possible way, it’s the beginning of something very exciting.” Scientists at Harvard University, Google and elsewhere prepared and analyzed the brain tissue sample. Smaller than a sesame seed, the bit of brain was about a millionth of an entire brain’s volume. It came from the cortex — the brain’s outer layer responsible for complex thought — of a 45-year-old woman undergoing surgery for epilepsy. After it was removed, the brain sample was quickly preserved and stained with heavy metals that revealed cellular structures. The sample was then sliced into more than 5,000 wafer-thin pieces and imaged with powerful electron microscopes. Computational programs stitched the resulting images back together and artificial intelligence programs helped scientists analyze them. A short description of the resulting view was published as a preprint May 30 to bioRxiv.org. The full dataset is freely available online. black background with green and purple nerve cells with lots of long tendrils These two neurons are mirror symmetrical. It’s unclear why these cells take these shapes. Lichtman Lab/Harvard University, Connectomics Team/Google For now, researchers are just beginning to see what’s there. “We have really just dipped our toe into this dataset,” says study coauthor Jeff Lichtman, a developmental neurobiologist at Harvard University. Lichtman compares the brain map to Google Earth: “There are gems in there to find, but no one can say they’ve looked at the whole thing.” © Society for Science & the Public 2000–2021.

Keyword: Brain imaging
Link ID: 27858 - Posted: 06.16.2021

By Thomas Ling Neuroscientists are poised to gain new insights into how our minds work, thanks to a breakthrough in non-invasive 3D brain scanning. Testing the new technique – which is called diffuse optical localisation imaging (DOLI) – researchers from the University of Zurich injected a live mouse with special fluorescent microdroplets that became distributed throughout the bloodstream. Highly efficient short-wave cameras (which take advantage of a near-infrared spectral window) tracked the fluorescent to draw a map of the deep cerebral network within the mouse’s brain. Previous microscopy techniques generated unclear images due to intense light scattering. However, the DOLI technique can create a clear picture of the brain at the capillary level by using a fluorescent filled with tiny lead-sulfide-based particles called quantum dots. Additionally, unlike past procedures, DOLI does not need to break the animal’s skull and scalp to work. It is hoped the new non-invasive technique will lead to a better understanding of how brains work, including how neurological diseases first form. “Enabling high-resolution optical observations in deep living tissues represents a long-standing goal in the biomedical imaging field,” said research team leader Prof Daniel Razansky, who published the group’s findings in Optica, The Optical Society’s journal. (C) BBC

Keyword: Brain imaging
Link ID: 27836 - Posted: 05.29.2021

Ian Sample Science editor A man who was paralysed from the neck down in an accident more than a decade ago has written sentences using a computer system that turns imagined handwriting into words. It is the first time scientists have created sentences from brain activity linked to handwriting and paves the way for more sophisticated devices to help paralysed people communicate faster and more clearly. The man, known as T5, who is in his 60s and lost practically all movement below his neck after a spinal cord injury in 2007, was able to write 18 words a minute when connected to the system. On individual letters, his “mindwriting” was more than 94% accurate. Frank Willett, a research scientist on the project at Stanford University in California, said the approach opened the door to decoding other imagined actions, such as 10-finger touch typing and attempted speech for patients who had permanently lost their voices. “Instead of detecting letters, the algorithm would be detecting syllables, or rather phonemes, the fundamental unit of speech,” he said. Amy Orsborn, an expert in neural engineering at the University of Washington in Seattle, who was not involved in the work, called it “a remarkable advance” in the field. Scientists have developed numerous software packages and devices to help paralysed people communicate, ranging from speech recognition programs to the muscle-driven cursor system created for the late Cambridge cosmologist Stephen Hawking, who used a screen on which a cursor automatically moved over the letters of the alphabet. To select one, and to build up words, he simply tensed his cheek. © 2021 Guardian News & Media Limited

Keyword: Brain imaging; Robotics
Link ID: 27822 - Posted: 05.15.2021

By Charles Q. Choi With the help of headsets and backpacks on mice, scientists are using light to switch nerve cells on and off in the rodents’ brains to probe the animals’ social behavior, a new study shows. These remote control experiments are revealing new insights on the neural circuitry underlying social interactions, supporting previous work suggesting minds in sync are more cooperative, researchers report online May 10 in Nature Neuroscience. The new devices rely on optogenetics, a technique in which researchers use bursts of light to activate or suppress the brain nerve cells, or neurons, often using tailored viruses to genetically modify cells so they respond to illumination (SN: 1/15/10). Scientists have used optogenetics to probe neural circuits in mice and other lab animals to yield insights on how they might work in humans (SN: 10/22/19). Optogenetic devices often feed light to neurons via fiber-optic cables, but such tethers can interfere with natural behaviors and social interactions. While scientists recently developed implantable wireless optogenetic devices, these depend on relatively simple remote controls or limited sets of preprogrammed instructions. These new fully implantable optogenetic arrays for mice and rats can enable more sophisticated research. Specifically, the researchers can adjust each device’s programming during the course of experiments, “so you can target what an animal does in a much more complex way,” says Genia Kozorovitskiy, a neurobiologist at Northwestern University in Evanston, Ill. © Society for Science & the Public 2000–2021.

Keyword: Brain imaging
Link ID: 27812 - Posted: 05.12.2021

Researchers are now able to wirelessly record the directly measured brain activity of patients living with Parkinson’s disease and to then use that information to adjust the stimulation delivered by an implanted device. Direct recording of deep and surface brain activity offers a unique look into the underlying causes of many brain disorders; however, technological challenges up to this point have limited direct human brain recordings to relatively short periods of time in controlled clinical settings. This project, published in the journal Nature Biotechnology, was funded by the National Institutes of Health’s Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative. “This is really the first example of wirelessly recording deep and surface human brain activity for an extended period of time in the participants’ home environment,” said Kari Ashmont, Ph.D., project manager for the NIH BRAIN Initiative. “It is also the first demonstration of adaptive deep brain stimulation at home.” Deep brain stimulation (DBS) devices are approved by the U. S. Food and Drug Administration for the management of Parkinson’s disease symptoms by implanting a thin wire, or electrode, that sends electrical signals into the brain. In 2018, the laboratory of Philip Starr, M.D., Ph.D. at the University of California, San Francisco, developed an adaptive version of DBS that adapts its stimulation only when needed based on recorded brain activity. In this study, Dr. Starr and his colleagues made several additional improvements to the implanted technology.

Keyword: Brain imaging
Link ID: 27800 - Posted: 05.05.2021

Enhancing the brain’s lymphatic system when administering immunotherapies may lead to better clinical outcomes for Alzheimer’s disease patients, according to a new study in mice. Results published April 28 in Nature suggest that treatments such as the immunotherapies BAN2401 or aducanumab might be more effective when the brain’s lymphatic system can better drain the amyloid-beta protein that accumulates in the brains of those living with Alzheimer’s. Major funding for the research was provided by the National Institute on Aging (NIA), part of the National Institutes of Health, and all study data is now freely available to the broader scientific community. “A broad range of research on immunotherapies in development to treat Alzheimer’s by targeting amyloid-beta has not to date demonstrated consistent results,” said NIA Director Richard J. Hodes, M.D. “While this study’s findings require further confirmation, the link it has identified between a well-functioning lymphatic system in the brain and the ability to reduce amyloid-beta accumulation may be a significant step forward in pursuing this class of therapeutics.” Abnormal buildup of amyloid-beta is one hallmark of Alzheimer’s disease. The brain’s lymphatic drainage system, which removes cellular debris and other waste, plays an important part in that accumulation. A 2018 NIA-supported study showed a link between impaired lymphatic vessels and increased amyloid-beta deposits in the brains of aging mice, suggesting these vessels could play a role in age-related cognitive decline and Alzheimer’s. The lymphatic system is made up of vessels which run alongside blood vessels and which carry immune cells and waste to lymph nodes. Lymphatic vessels extend into the brain’s meninges, which are membranes that surround the brain and spinal cord.

Keyword: Alzheimers; Sleep
Link ID: 27795 - Posted: 05.01.2021

By Noah Hutton Twelve years ago, when I graduated college, I was well aware of the Silicon Valley hype machine, but I considered the salesmanship of private tech companies a world away from objective truths about human biology I had been taught in neuroscience classes. At the time, I saw the neuroscientist Henry Markram proclaim in a TED talk that he had figured out a way to simulate an entire human brain on supercomputers within 10 years. This computer-simulated organ would allow scientists to instantly and noninvasively test new treatments for disorders and diseases, moving us from research that depends on animal experimentation and delicate interventions on living people to an “in silico” approach to neuroscience. My 22-year-old mind didn’t clock this as an overhyped proposal. Instead, it felt exciting and daring, the kind of moment that transforms a distant scientific pipe dream into a suddenly tangible goal and motivates funders and fellow researchers to think bigger. And so I began a 10-year documentary project following Markram and his Blue Brain Project, with the start of the film coinciding with the beginning of an era of big neuroscience where the humming black boxes produced by Silicon Valley came to be seen as the great new hope for making sense of the black boxes between our ears. My decade-long journey documenting Markram’s vision has no clear answers except perhaps one: that flashy presentations and sheer ambition are poor indicators of success when it comes to understanding the complex biological mechanisms of brains. Today, as we bear witness to a game of Pong being mind-controlled by a monkey as part of a typically bombastic demonstration by Elon Musk’s start-up Neuralink, there is more of a need than ever to unwind the cycles of hype in order to grapple with what the future of brain technology and neuroscience have in store for humanity. © 2021 Scientific American

Keyword: Brain imaging; Robotics
Link ID: 27794 - Posted: 05.01.2021

Lise Eliot Everyone knows the difference between male and female brains. One is chatty and a little nervous, but never forgets and takes good care of others. The other is calmer, albeit more impulsive, but can tune out gossip to get the job done. These are stereotypes, of course, but they hold surprising sway over the way actual brain science is designed and interpreted. Since the dawn of MRI, neuroscientists have worked ceaselessly to find differences between men’s and women’s brains. This research attracts lots of attention because it’s just so easy to try to link any particular brain finding to some gender difference in behavior. But as a neuroscientist long experienced in the field, I recently completed a painstaking analysis of 30 years of research on human brain sex differences. And what I found, with the help of excellent collaborators, is that virtually none of these claims has proven reliable. Except for the simple difference in size, there are no meaningful differences between men’s and women’s brain structure or activity that hold up across diverse populations. Nor do any of the alleged brain differences actually explain the familiar but modest differences in personality and abilities between men and women. © 2010–2021, The Conversation US, Inc.

Keyword: Sexual Behavior; Brain imaging
Link ID: 27784 - Posted: 04.24.2021

by Angie Voyles Askham A dearth of insulation around neuronal projections may explain why some parts of the cerebral cortex can appear thicker in brain scans of autistic people than in those of non-autistic people, according to a new study. Magnetic resonance imaging (MRI) studies show that some autistic children have bigger brains than their non-autistic peers, with much of the overgrowth occurring in the cerebral cortex. The reason for this difference remains unclear, but it seems to reflect an apparent excess of gray matter, which consists of neuronal cell bodies, relative to white matter, composed of neuronal projections. Newly developed neurons in the brains of autistic people may have trouble migrating to the proper place, some researchers have suggested, which could blur the boundary between gray and white matter in some regions and cause the gray matter to look thicker on an MRI scan. But higher levels of myelin, the insulation that surrounds neuronal projections, in non-autistic people could also skew these measures, says lead researcher of the new work, Mallar Chakravarty, associate professor of psychiatry at McGill University in Montreal. Myelin appears brighter on an MRI scan than other tissue, so an abundance of it near the boundary between gray and white matter could make the gray matter appear thinner, he says. © 2021 Simons Foundation

Keyword: Autism; Glia
Link ID: 27783 - Posted: 04.24.2021

By Kelly Servick The most advanced mind-controlled devices being tested in humans rely on tiny wires inserted into the brain. Now researchers have paved the way for a less invasive option. They’ve used ultrasound imaging to predict a monkey’s intended eye or hand movements—information that could generate commands for a robotic arm or computer cursor. If the approach can be improved, it may offer people who are paralyzed a new means of controlling prostheses without equipment that penetrates the brain. “This study will put [ultrasound] on the map as a brain-machine interface technique,” says Stanford University neuroscientist Krishna Shenoy, who was not involved in the new work. “Adding this to the toolkit is spectacular.” Doctors have long used sound waves with frequencies beyond the range of human hearing to create images of our innards. A device called a transducer sends ultrasonic pings into the body, which bounce back to indicate the boundaries between different tissues About a decade ago, researchers found a way to adapt ultrasound for brain imaging. The approach, known as functional ultrasound, uses a broad, flat plane of sound instead of a narrow beam to capture a large area more quickly than with traditional ultrasound. Like functional magnetic resonance imaging (fMRI), functional ultrasound measures changes in blood flow that indicate when neurons are active and expending energy. But it creates images with much finer resolution than fMRI and doesn’t require participants to lie in a massive scanner. The technique still requires removing a small piece of skull, but unlike implanted electrodes that read neurons’ electrical activity directly, it doesn’t involve opening the brain’s protective membrane, notes neuroscientist Richard Andersen of the California Institute of Technology (Caltech), a co-author of the new study. Functional ultrasound can read from regions deep in the brain without penetrating the tissue. © 2021 American Association for the Advancement of Science.

Keyword: Brain imaging
Link ID: 27741 - Posted: 03.23.2021

By Christa Lesté-Lasserre The famed stallion Black Beauty felt joy, excitement, and even heartbreak—or so he tells us in the 1877 novel that bears his name. Now, scientists say they’ve been able to detect feelings in living animals by getting them straight from the horse’s mouth—or in this case, its head. Researchers have devised a new, mobile headband that detects brain waves in horses, which could eventually be used with other species. “This is a real breakthrough,” says Katherine Houpt, a veterinary behaviorist at Cornell University who was not involved with the work. The device, she says, “gets into the animals’ minds” with objectivity and less guesswork. Ethologist Martine Hausberger had the idea while investigating whether stressed horses had a harder time learning to open a sliding door over a food box. (Spoiler alert: They do.) Hausberger, of the University of Rennes, noticed some of the animals—specifically, those living in cramped spaces—were paying less attention to the lessons. Were they depressed? An electroencephalogram (EEG) could theoretically pick up on such a mental state. Scientists have used the devices, which record waves of electrical impulses in the brain, since the early 1900s to study epilepsy and sleep patterns. More recently, they’ve discovered that certain EEG waves can signal depression, anxiety, and even contentedness in humans. EEG studies in rodents, farm animals, and pets, meanwhile, have revealed how they react to being touched by a human or undergoing anesthesia. But so far, no one had found a way to record brain waves in animals while they move around. © 2021 American Association for the Advancement of Science.

Keyword: Brain imaging
Link ID: 27723 - Posted: 03.11.2021

By Laura Sanders A century ago, science’s understanding of the brain was primitive, like astronomy before telescopes. Certain brain injuries were known to cause specific problems, like loss of speech or vision, but those findings offered a fuzzy view. Anatomists had identified nerve cells, or neurons, as key components of the brain and nervous system. But nobody knew how these cells collectively manage the brain’s sophisticated control of behavior, memory or emotions. And nobody knew how neurons communicate, or the intricacies of their connections. For that matter, the research field known as neuroscience — the science of the nervous system — did not exist, becoming known as such only in the 1960s. Over the last 100 years, brain scientists have built their telescopes. Powerful tools for peering inward have revealed cellular constellations. It’s likely that over 100 different kinds of brain cells communicate with dozens of distinct chemicals. A single neuron, scientists have discovered, can connect to tens of thousands of other cells. Yet neuroscience, though no longer in its infancy, is far from mature. Today, making sense of the brain’s vexing complexity is harder than ever. Advanced technologies and expanded computing capacity churn out torrents of information. “We have vastly more data … than we ever had before, period,” says Christof Koch, a neuroscientist at the Allen Institute in Seattle. Yet we still don’t have a satisfying explanation of how the brain operates. We may never understand brains in the way we understand rainbows, or black holes, or DNA. © Society for Science & the Public 2000–2021.

Keyword: Brain imaging; Learning & Memory
Link ID: 27722 - Posted: 03.06.2021

By Alex Vadukul In the early 1970s, the field of neuroradiology was still in its formative years, and among its early practitioners was Dr. John Bentson, at UCLA Medical Center in Los Angeles. As he helped patients with the aid of new technology like the CT scan and computer imaging, he saw an opportunity for innovation. A subspecialty of radiology, neuroradiology involves diagnosing and treating ailments in the brain, spinal cord and nerves. One tool used in treatment is the combination of an angiographic guidewire and catheter, essentially a slender wire and tube. Inserted through the leg, it can aid with the injection of contrast dye for diagnostic brain imaging and the treatment of aneurysms. At the time, however, guidewires were rigid and at worst could injure a blood vessel. Dr. Bentson decided to design a better type. He conceived of a more supple guidewire that also featured a flexible tip, and after UCLA built an early prototype for him, other neuroradiologists started using his model. Cook Medical began manufacturing the device in 1973, and it’s still in use today, commonly known as a Bentson guidewire. Dr. Bentson died at 83 on Dec. 28 at a hospital in Los Angeles. The cause was complications of Covid-19, his daughter Dr. Erika Drazan said. “He liked to push boundaries if he thought he could help the patient,” she said. “He liked saying that the vessels in the body are just like a tree, and that he could get where he wanted through them by feel.” Thousands of patients have benefited from his innovation, The American Society of Neuroradiology said after his death. John Reinert Bentson was born on May 15, 1937, in Viroqua, Wis., to Carl and Stella (Hagen) Bentson, who were of Norwegian heritage. He was raised on his family’s dairy farm, going to school in the winter on wooden skis. His mother prepared Norwegian fare like lutefisk. © 2021 The New York Times Company

Keyword: Brain imaging; Stroke
Link ID: 27689 - Posted: 02.15.2021

By Laura Sanders In the late 1800s, Santiago Ramón y Cajal, a Spanish brain scientist, spent long hours in his attic drawing elaborate cells. His careful, solitary work helped reveal individual cells of the brain that together create wider networks. For those insights, Cajal received a Nobel Prize for physiology or medicine in 1906. Now, a group of embroiderers has traced those iconic cell images with thread, paying tribute to the pioneering drawings that helped us see the brain clearly. The Cajal Embroidery Project was launched in March of 2020 by scientists at the University of Edinburgh. Over a hundred volunteers — scientists, artists and embroiderers — sewed panels that will ultimately be stitched into a tapestry, a project described in the December Lancet Neurology. Catherine Abbott, a neuroscientist at the University of Edinburgh, had the idea while talking with her colleague Jane Haley, who was planning an exhibit of Cajal’s drawings. These meticulous drawings re-created nerve cells, or neurons, and other types of brain cells, including support cells called astrocytes. “I said, off the cuff, ‘Wouldn’t it be lovely to embroider some of them?’” © Society for Science & the Public 2000–2021.

Keyword: Brain imaging
Link ID: 27679 - Posted: 02.08.2021

Catherine S. Woolley, Ph.D. Sex differences in the brain are real, but they are not what you might think. They’re not about who is better at math, reading a map, or playing chess. They’re not about being sensitive or good at multi-tasking, either. Sex differences in the brain are about medicine and about making sure that the benefits of biomedical research are relevant for everyone, both men and women. You may be surprised to learn that most animal research is done in males. This is based on an erroneous view that hormonal cycles complicate studies in female research animals, and an assumption that the sexes are essentially the same down at cellular and molecular levels. But these beliefs are starting to change in neuroscience. New research shows that some fundamental molecular pathways in the brain operate differently in males and females, and not just by a little. In some cases, molecular sex differences are all-or-nothing. Recognition that male and female brains differ at a molecular level has the potential to transform biomedical research. Drugs act on molecular pathways. If those pathways differ between the sexes, we need to know how they differ as early as possible in the long (and expensive) process of developing new medicines and treatments for disease. The bulk of public attention to brain sex differences is focused on structural differences and their purported relationship to behavior or cognition. Yet structural sex differences are actually quite small, and their interpretation is often based on gender stereotypes with little to no scientific justification. © 2021 The Dana Foundation

Keyword: Sexual Behavior; Brain imaging
Link ID: 27650 - Posted: 01.15.2021

Alison Abbott In October 2013, I attended the launch of the Human Brain Project in Lausanne, Switzerland, as correspondent for Nature. I hoped to leave with a better understanding of the exact mission of the baffling billion-euro enterprise, but I was frustrated. Things became clear the following year, when the project fell spectacularly, and very publicly, apart. Noah Hutton’s documentary In Silico captures a sense of what it was like behind the scenes of the project, which was supported with great fanfare by the European Commission. It had been hyped as a quantum leap in understanding how the human brain works. Instead, it left a trail of angry neuroscientists across Europe. Yet aspects of what went so expensively wrong still remain elusive. In Silico is more about the back story of the Human Brain Project (HBP). Hutton was 22 years old when he watched a 2009 talk by Henry Markram, the controversial figure who later became the first director of the HBP. Markham was speaking about the Blue Brain Project, a major initiative he had launched a few years before at one of Europe’s top universities, the Swiss Federal Institute of Technology in Lausanne, with generous funding from the Swiss government. He claimed that he would — with the help of a supercomputer related to the one that beat world chess champion Garry Kasparov in 1997 — simulate an entire rodent brain within a decade. He planned to build it from information about the brain’s tens of millions of individual neurons. © 2020 Springer Nature Limited

Keyword: Brain imaging
Link ID: 27614 - Posted: 12.09.2020

by Laura Dattaro Autistic boys with large brains in early childhood still have large brains in adolescence, according to a new study. Autistic girls, too, have brains that grow differently from those of their non-autistic peers. The findings challenge the long-standing idea that brain enlargement in autism is temporary. Previous studies indicated that young children on the spectrum have larger brains than their non-autistic peers but older people with autism do not. To explain the difference, researchers speculated that a pruning process follows early brain overgrowth. But the changes are a mirage, the researchers behind the new study say: Because having a large brain is associated with a low intelligence quotient (IQ) and severe autism traits, and because older children with such characteristics are often excluded from imaging studies, the prior results reflect only a lack of older participants with large brains. “This whole idea of this early overgrowth followed by normalization is just an artifact of sampling bias,” says lead investigator Christine Wu Nordahl, associate professor of psychiatry and behavioral sciences at the University of California, Davis MIND Institute. “It was sort of like, ‘Wow, why didn’t we ever think about this before?’ But it’s pretty clear that that’s what’s happening.” Autistic and non-autistic children also show different development patterns in their white matter — fibers that connect regions of the brain — in early childhood, a second study from Nordahl’s group shows. Some of the differences correlate with changes in the children’s autism traits over time. © 2020 Simons Foundation

Keyword: Autism; Brain imaging
Link ID: 27598 - Posted: 11.30.2020

By Lindsay Gray When Herbert Weinstein stood trial for the murder of his wife in 1992, his attorneys were struck by the measured calm with which he recounted her death and the events leading up to it. He made no attempt to deny that he was culpable, and yet his stoicism in the face of his wildly uncharacteristic actions led his defense to suspect that he might not be. Weinstein underwent neuroimaging tests, which confirmed what his attorneys had suspected: a cyst had impinged upon large parts of Weinstein’s frontal lobe, the seat of impulse control in the brain. On these grounds, they reasoned he should be found not guilty by reason of insanity, despite Weinstein’s free admission of guilt. Guilt is difficult to define, but it pervades every aspect of our lives, whether we’re chastising ourselves for skipping a workout, or serving on the jury of a criminal trial. Humans seem to be hardwired for justice, but we’re also saddled with a curious compulsion to diagram our own emotional wiring. This drive to assign a neurochemical method to our madness has led to the generation of vast catalogs of neuroimaging studies that detail the neural underpinnings of everything from anxiety to nostalgia. In a recent study, researchers now claim to have moved us one step closer to knowing what a guilty brain looks like. Since guilt carries different weight depending on context or culture, the authors of the study chose to define it operationally as the awareness of having harmed someone else. A series of functional magnetic resonance imaging (fMRI) experiments across two separate cohorts, one Swiss and one Chinese, revealed what they refer to as a “guilt-related brain signature” that persists across groups. Since pervasive guilt is a common feature in severe depression and PTSD, the authors suggest that a neural biomarker for guilt could offer more precise insight into these conditions and, potentially, their treatment. But brain-based biomarkers for complex human behaviors also lend themselves to the more ethically fraught discipline of neuroprediction, an emergent branch of behavioral science that combines neuroimaging data and machine learning to forecast how an individual is likely to act based on how their brain scans compare to those of other groups. © 2020 Scientific American,

Keyword: Stress; Brain imaging
Link ID: 27591 - Posted: 11.21.2020

Researchers at the National Eye Institute (NEI) have decoded brain maps of human color perception. The findings, published today in Current Biology, open a window into how color processing is organized in the brain, and how the brain recognizes and groups colors in the environment. The study may have implications for the development of machine-brain interfaces for visual prosthetics. NEI is part of the National Institutes of Health. “This is one of the first studies to determine what color a person is seeing based on direct measurements of brain activity,” said Bevil Conway, Ph.D., chief of NEI’s Unit on Sensation, Cognition and Action, who led the study. “The approach lets us get at fundamental questions of how we perceive, categorize, and understand color.” The brain uses light signals detected by the retina’s cone photoreceptors as the building blocks for color perception. Three types of cone photoreceptors detect light over a range of wavelengths. The brain mixes and categorizes these signals to perceive color in a process that is not well understood. To examine this process, Isabelle Rosenthal, Katherine Hermann, and Shridhar Singh, post-baccalaureate fellows in Conway’s lab and co-first authors on the study, used magnetoencephalography or “MEG,” a 50-year-old technology that noninvasively records the tiny magnetic fields that accompany brain activity. The technique provides a direct measurement of brain cell activity using an array of sensors around the head. It reveals the millisecond-by-millisecond changes that happen in the brain to enable vision. The researchers recorded patterns of activity as volunteers viewed specially designed color images and reported the colors they saw.

Keyword: Vision; Brain imaging
Link ID: 27588 - Posted: 11.21.2020

In a 2009 TED Talk, Israeli neuroscientist Henry Markram made a shocking claim: he was going to create a machine version of human brain within 10 years. The project was catnip to filmmaker Noah Hutton, who began documenting Markram's quest. Ultimately, Hutton followed Markram for a decade — but the scientist's lofty goal remains conspicuously incomplete. The resulting film, In Silico, finally makes its world premiere as part of the online version of the DOC NYC film festival on November 11. The film traces Markram’s journey with the Human Brain Project, from the project’s inception to its $1.4 billion in funding from the European Commission — and how it failed to meet its 10-year goal by 2019. Following a neuroscientist for a decade reveals a lot of highs and lows. Hutton presents the controversies by interviewing both the Human Brain Project team and its critics, including Princeton neuroscientist Sebastian Seung, researcher Zach Mainen at the Champalimaud Centre for the Unknown based in Portugal, and experimental cognitive psychologist Stanislas Dehane, who is professor at Collège de France in Paris. The film also features candid interviews with neuroscientists Christof Koch, who head's up the Allen Institute's MindScope Program, Harvard University's Jeremy R. Knowles Professor of Molecular and Cellular Biology Jeff W. Lichtman, and Stanford University neuroscience adjunct professor David Eagleman. Neuroscientists Idan Segev of Hebrew University in Israel, Cori Bargmann, Torsten N. Weisel Professor of Genetics and Genomics and Neuroscience and Behavior at Rockefeller University, and Cold Spring Harbor Lab professor Anne Churchland.

Keyword: Brain imaging
Link ID: 27577 - Posted: 11.14.2020