James Gorman Humans, chimpanzees, elephants, magpies and bottle-nosed dolphins can recognize themselves in a mirror, according to scientific reports, although as any human past age 50 knows, that first glance in the morning may yield ambiguous results. Not to worry. Scientists are talking about species-wide abilities, not the fact that one’s father or mother makes unpredictable appearances in the looking glass. Mirror self-recognition, at least after noon, is often taken as a measure of a kind of intelligence and self-awareness, although not all scientists agree. And researchers have wondered not only about which species display this ability, but about when it emerges during early development. Children start showing signs of self-recognition at about 12 months at the earliest and chimpanzees at two years old. But dolphins, researchers reported Wednesday, start mugging for the mirror as early as seven months, earlier than humans. Diana Reiss a psychologist at Hunter College, and Rachel Morrison, then a graduate student working with Reiss, studied two young dolphins over three years at the National Aquarium in Baltimore. Dr. Reiss first reported self-recognition in dolphins in 2001 with Lori Marino, now the head of The Kimmela Center for Animal Advocacy. She and Dr. Morrison, now an assistant professor in the psychology department at the University of North Carolina Pembroke collaborated on the study and published their findings in the journal PLoS One. Dr. Reiss said the timing of the emergence of self-recognition is significant, because in human children the ability has been tied to other milestones of physical and social development. Since dolphins develop earlier than humans in those areas, the researchers predicted that dolphins should show self-awareness earlier. Seven months was when Bayley, a female, started showing self-directed behavior, like twirling and taking unusual poses. © 2018 The New York Times Company

Keyword: Consciousness; Evolution
Link ID: 24519 - Posted: 01.11.2018

By Matthew Hutson Imagine searching through your digital photos by mentally picturing the person or image you want. Or sketching a new kitchen design without lifting a pen. Or texting a loved one a sunset photo that was never captured on camera. A computer that can read your mind would find many uses in daily life, not to mention for those paralyzed and with no other way to communicate. Now, scientists have created the first algorithm of its kind to interpret—and accurately reproduce—images seen or imagined by another person. It might be decades before the technology is ready for practical use, but researchers are one step closer to building systems that could help us project our inner mind’s eye outward. “I was impressed that it works so well,” says Zhongming Liu, a computer scientist at Purdue University in West Lafayette, Indiana, who helped develop an algorithm that can somewhat reproduce what moviegoers see when they’re watching a film. “This is really cool.” Using algorithms to decode mental images isn’t new. Since 2011, researchers have recreated movie clips, photos, and even dream imagery by matching brain activity to activity recorded earlier when viewing images. But these methods all have their limits: Some deal only with narrow domains like face shape, and others can’t build an image from scratch—instead, they must select from preprogrammed images or categories like “person” or “bird.” This new work can generate recognizable images on the fly and even reproduce shapes that are not seen, but imagined. © 2018 American Association for the Advancement of Science.

Keyword: Vision; Brain imaging
Link ID: 24518 - Posted: 01.11.2018

Richard Harris The results of an IQ test can depend on the gender of the person who's conducting the test. Likewise, studies of pain medication can be completely thrown off by the gender of the experimenter. This underappreciated problem is one reason that some scientific findings don't stand the test of time. Colin Chapman found out about this problem the hard way. He had traveled to Sweden on a Fulbright scholarship to launch his career in neuroscience. And he decided to study whether a nasal spray containing a hormone called oxytocin would help control obesity. The hormone influences appetite and impulsive behavior in obese men. "I was really excited about this project, from what I understood about how the brain works, I thought it was kind of a slam dunk," he says. Chapman set up the experiment and then left for a few years to attend Harvard Law School. When he returned, the findings were not at all what he expected, "and I was really disappointed because this was my baby, it was my big project going into neuroscience." But Chapman, who is now a graduate student at the University of Uppsala, says his idea turned out to be right after all. "There was another research group that around the same time came up with the same idea," he says. "And they ran basically the same project and they got exactly the results I was expecting to get." © 2018 npr

Keyword: Sexual Behavior; Pain & Touch
Link ID: 24517 - Posted: 01.11.2018

By KAREN WEINTRAUB Male sea turtles are disappearing from Australia’s Great Barrier Reef. A new study of gender ratios found that 99 percent of immature green turtles born in the northern part of the reef are female. Among adult turtles, 87 percent are female, suggesting that there has been a shift in gender ratios over the last few decades. A sea turtle’s sex is determined by its nesting environment. As sands warm, more females will hatch relative to males; if the sand temperature tops 84.7 degrees during incubation, only females will emerge. The gender shift suggests that climate change is having a significant effect on one of the biggest green turtle populations in the world, said Michael Jensen, lead author of the new study, published in Current Biology. “We’re all trying to wrap our heads around how these populations are going to respond to those changes,” said Dr. Jensen, a marine biologist with the National Oceanic and Atmospheric Administration in San Diego. The gender shift has been noticed before by people who study hatchlings, said Jeanette Wyneken, a sea turtle expert and professor at Florida Atlantic University, who was not involved in the new research. But it wasn’t clear until this study that the shift was so dramatic and happening in such a large population across time, she said. “This is the first paper that’s shown this multigenerational effect,” influencing the gender of juveniles, older adolescents and adults, Dr. Wyneken said. It takes 35 to 40 years for a green sea turtle to reach sexual maturity, she said. “These animals are teenagers for an awfully long time,” Dr. Wyneken said. “We won’t see the effects of what’s happening today for several decades.” David Owens, a professor emeritus from the College of Charleston in South Carolina, was not involved in the new study, but said he’s dreamed of doing such research for years. He praised the way the study team — which included a wide range of expertise — was able to link temperature with turtle gender. © 2018 The New York Times Company

Keyword: Sexual Behavior
Link ID: 24516 - Posted: 01.11.2018

By LISA FOGARTY The last time I tasted my birthday cake was the spring I turned 13, a few months before I discovered the elimination game. The game went like this: first, stop eating sweets. Second, blot sauces, oils and dressings with paper towels while no one was looking. Third, count grams of fat, reject any food with over 3 grams, and keep a calorie tally in the back of your math notebook (where, if someone found it, they’d assume it was just math). The elimination game also involved adding. Add the toilet bowl and the sewer down the street to the list of places you could discard food. Add candy bar wrappers and empty full-fat yogurt containers to your bedroom nightstand as evidence that you’re not sick. Finally, add up the pounds you’ve lost that week that signify victory. So easy. Repeat. At 38, I am a former anorexic in recovery. Over the years, I’ve discovered my strengths — making my two children feel loved, encouraging sources to open up for stories I write as a magazine reporter — but I’ve never been as good at anything as I was at the elimination game. Growing up in leafy suburban Queens, N.Y., I became obsessed with made-for-TV movies from the ’80s and ’90s about anorexia. All of my early eating disorder role models — a nightmarish choice of words, but when you’re in the grip of this mental disorder, that’s what they are — were scared, sad and relatable. They were also all very, very young. My stars were Karen Carpenter, Tracy Gold and my favorite, Jennifer Jason Leigh, who, in the 1981 movie “The Best Little Girl in the World,” appeared appealingly helpless in high-waisted jeans. With one exception, these movies wrapped up anorexia in tidy boxes where therapy, feeding tubes, weight gain, finding release from a controlling mother’s grip and discovering the joys of food led to a happy ending. I was a kid who no longer ate dessert when I watched Ms. Leigh’s character jovially lick an ice cream cone beside her therapist. But even I knew then that ice cream was neither the problem nor the solution. © 2018 The New York Times Company

Keyword: Anorexia & Bulimia
Link ID: 24515 - Posted: 01.11.2018

Nicola Davis The quest to develop drugs to treat Alzheimer’s disease has experienced a new setback, with a promising medication failing to show benefits in the latest series of clinical trials. Earlier trials had suggested that the drug idalopirdine, from the Danish international pharmaceutical company Lundbeck, might improve cognition in those with Alzheimer’s disease when taken alongside existing drugs – known as cholinesterase inhibitors – acting to improve symptoms rather than stopping the disease from developing. But the latest trials have dashed such hopes. “I was personally very excited,” said professor Clive Ballard, co-author of the study from the University of Exeter, pointing out that previous trials had appeared promising. “It is very disappointing that it then didn’t pan out.” Analysis This may be a turning point in treating neurodegenerative diseases Success in trials for Huntington’s and Spinal Muscular Atrophy, raises hopes that diseases such as Alzheimer’s and ALS could be tackled using a new class of drugs Read more Writing in the Journal of the American Medical Association, an international team of researchers report how they carried out three clinical trials involving a total of 2,525 participants in 34 countries, to explore the impact of idalopirdine. All participants were aged 50 years or older and had mild to moderate Alzheimer’s disease. © 2018 Guardian News and Media Limited

Keyword: Alzheimers
Link ID: 24514 - Posted: 01.10.2018

By Diana Kwon Centuries ago, humans believed that seizures were tied to the lunar cycle. Although scientific evidence for this association is scarce, physicians have long suspected that temporal patterns connected with epilepsy may exist. These days, the condition’s link to our sleep-wake cycles, or circadian rhythms, is well-documented, primarily through observations that seizures are more prevalent at night or tend to occur at specific times of day. Scientists now report the existence of seizure-associated brain rhythms with longer periods, most commonly within the 20- to 30-day range, in a study published today (January 8) in Nature Communications. “People have made these observations since antiquity and have wanted to speculate and explain these oscillations for a long time,” study coauthor Vikram Rao, a neurologist at the University of California, San Francisco, tells The Scientist. “But only recently [have we gotten] the tools that might allow us to actually unravel this.” Rao and his colleagues analyzed data collected from one such tool—the NeuroPace device, an FDA-approved, implanted brain stimulator that continuously monitors neural activity and sends electrical pulses when a seizure is imminent. It acts, in some sense, like a “pacemaker for the brain,” Rao says. The device detects and records both seizures and interictal epileptiform discharges, pathological brain activity associated with these events, using electroencephalography (EEG). “In between seizures, we see electric discharges that signify irritability of the brain and a propensity to have seizures,” Rao explains. “It’s like seeing sparks from a match, where you say, wow, that looks like there’s potential for a fire but it’s not the fire itself.” © 1986-2018 The Scientist

Keyword: Epilepsy; Biological Rhythms
Link ID: 24513 - Posted: 01.10.2018

Aimee Cunningham Internist Gail Povar has many female patients making their way through menopause, some having a tougher time than others. Several women with similar stories stand out in her mind. Each came to Povar’s Silver Spring, Md., office within a year or two of stopping her period, complaining of frequent hot flashes and poor sleep at night. “They just felt exhausted all the time,” Povar says. “The joy had kind of gone out.” And all of them “were just absolutely certain that they were not going to take hormone replacement,” she says. But the women had no risk factors that would rule out treating their symptoms with hormones. So Povar suggested the women try hormone therapy for a few months. “If you feel really better and it makes a big difference in your life, then you and I can decide how long we continue it,” Povar told them. “And if it doesn’t make any difference to you, stop it.” At the follow-up appointments, all of these women reacted the same way, Povar recalls. “They walked in beaming, absolutely beaming, saying, ‘I can’t believe I didn’t do this a year ago. My life! I’ve got my life back.’ ” That doesn’t mean, Povar says, that she’s pushing hormone replacement on patients. “But it should be on the table,” she says. “It should be part of the discussion.” Hormone replacement therapy toppled off the table for many menopausal women and their doctors in 2002. That’s when a women’s health study, stopped early after a data review, published results linking a common hormone therapy to an increased risk of breast cancer, heart disease, stroke and blood clots. The trial, part of a multifaceted project called the Women’s Health Initiative, or WHI, was meant to examine hormone therapy’s effectiveness in lowering the risk of heart disease and other conditions in women ages 50 to 79. It wasn’t a study of hormone therapy for treating menopausal symptoms. |© Society for Science & the Public 2000 - 2018.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 24512 - Posted: 01.10.2018

By Abby Olena Most mammalian cells have a primary cilium, an antenna-like, immobile surface projection that senses the surrounding environment. Researchers report in Nature Genetics today (January 8) that proteins localized to the cilia of neurons in the hypothalamus control food intake in mice. Furthermore, two human genetics studies published in Nature Genetics today tie variants of a neuronal ciliary gene, adenylyl cyclase 3 (ADCY3), identified in people from Pakistan, Greenland, and the United States, to an increased risk of obesity and diabetes. “This [mouse] paper contributes nicely to a consensus that cilia are important in the brain for energy homeostasis and feeding behaviors,” says Nick Berbari, a biologist at Indiana University–Purdue University Indianapolis who did not participate in the study. “It’s interesting to think about how cilia function could be important for the general population, [not] just in rare instances of ciliopathies,” he adds. Ciliopathies—rare diseases caused by mutations in genes that affect the primary cilia—can produce a variety of symptoms, including extra fingers or toes, retinal degeneration, and obesity, coauthor Christian Vaisse, a geneticist at the University of California, San Francisco, tells The Scientist. “Relatively recently, it was found that the obesity in ciliopathies was linked to a role of the primary cilium in neurons because the genetic removal of primary cilia from all neurons in an adult mouse leads to obesity,” he explains. © 1986-2018 The Scientist

Keyword: Obesity
Link ID: 24511 - Posted: 01.10.2018

Want to eat better? Sleep more. Increasing the amount of sleep a person gets has been linked to eating fewer sugary foods, and making better nutritional choices. Wendy Hall, at King’s College London, and her team enlisted 42 volunteers to help them investigate the link between sleep and diet. Half the participants were given advice on how to get more sleep – such as avoiding caffeine before bed, establishing a relaxing routine, and trying not to go to bed too full or hungry. This advice was intended to help them boost the amount of sleep they each got by 90 minutes a night. The remaining 21 volunteers received no such advice. The team found that, of those who were given the advice, 86 per cent spent more time in bed, and around half slept for longer than they used to. These extended sleep patterns were associated with an average reduction in the intake of free sugars of 10 grams a day. People who were getting more sleep also ate fewer carbohydrates. There were no significant changes in diet in the control group. Free sugars include those that are added to foods by manufacturers or during cooking at home, as well as sugars in honey, syrups and fruit juice. “The fact that extending sleep led to a reduction in intake of free sugars suggests that a simple change in lifestyle may really help people to consume healthier diets,” says Hall. © Copyright New Scientist Ltd.

Keyword: Sleep; Obesity
Link ID: 24510 - Posted: 01.10.2018

Ashley Juavinett Objectivity may be science’s holy grail, but the experiences of its practitioners have a large effect. Here are first-person essays from the front... Being a neuroscientist means I have a lot of awkward conversations in Home Depot. “What do you need it for?” the sales guy inquires after I ask where I might find Kapton tape, a special polyimide tape to protect electronics. “… an experiment,” I sheepishly answer. “Yeah, but like, what, exactly?” I pause. I’m usually eager to explain that I’m a neuroscientist who wants to know how the brain combines information to make decisions. I started my career by measuring the activity in large sections of human brains, but these coarse snapshots didn’t answer my questions. My questions, like this eager employee’s, required a more technical level of explanation. It’s a level of explanation I’m reluctant to offer. I do research with animals, and those parts of my job are hard to talk about. I need the tape to protect an electronic recording device that I’ve implanted on a mouse’s head, so that I can listen to hundreds of neurons in its brain. “I need it to protect some electronics,” I offer the Home Depot guy. Vague, but sufficient.

Keyword: Animal Rights
Link ID: 24509 - Posted: 01.10.2018

Johann Hari In the 1970s, a truth was accidentally discovered about depression – one that was quickly swept aside, because its implications were too inconvenient, and too explosive. American psychiatrists had produced a book that would lay out, in detail, all the symptoms of different mental illnesses, so they could be identified and treated in the same way across the United States. It was called the Diagnostic and Statistical Manual. In the latest edition, they laid out nine symptoms that a patient has to show to be diagnosed with depression – like, for example, decreased interest in pleasure or persistent low mood. For a doctor to conclude you were depressed, you had to show five of these symptoms over several weeks. The manual was sent out to doctors across the US and they began to use it to diagnose people. However, after a while they came back to the authors and pointed out something that was bothering them. If they followed this guide, they had to diagnose every grieving person who came to them as depressed and start giving them medical treatment. If you lose someone, it turns out that these symptoms will come to you automatically. So, the doctors wanted to know, are we supposed to start drugging all the bereaved people in America? The authors conferred, and they decided that there would be a special clause added to the list of symptoms of depression. None of this applies, they said, if you have lost somebody you love in the past year. In that situation, all these symptoms are natural, and not a disorder. It was called “the grief exception”, and it seemed to resolve the problem. © 2018 Guardian News and Media Limited

Keyword: Depression
Link ID: 24508 - Posted: 01.09.2018

Dean Burnett I do not know Johann Hari. We’ve never crossed paths, he’s done me no wrong that I’m aware of, I have no axe to grind with him or his work. And, in fairness, writing about mental health and how it’s treated or perceived is always a risk. It’s a major and often-debilitating issue facing a huge swathe of the population, and with many unpleasant and unhelpful stigmas attached. In recent years there have been signs that the tide is perhaps turning the right way, but a lot of work remains to be done. However, if you’re going to allow an extract from your book to be published as a standalone article for mainstream media with a title as provocative as “Is everything you know about depression wrong?”, you’d best make sure you have impeccable credentials and standards to back it up. Let’s address the elephant in the room: Johann Hari does not have a flawless reputation. He has been absent from the spotlight for many years following a plagiarism scandal, compounded by less-than-dignified behaviour towards his critics. Admittedly, he has since shown remorse and contrition over the whole affair, but even a cursory glance online reveals he’s a long way from universal forgiveness. Logically, someone with a reputation for making false claims should be the last person making high-profile, controversial, sweeping statements about something as sensitive as mental health. And yet, here we are. It’s 2018 after all. But let’s take the whole thing at face value and assume Hari has written this article with 100% good intentions and practices. Do his arguments and claims hold water? © 2018 Guardian News and Media Limited

Keyword: Depression
Link ID: 24507 - Posted: 01.09.2018

Singing could help mothers recover from post-natal depression more quickly, a study suggests. Researchers found that women who took part in group singing sessions with their babies experienced a much faster improvement in their symptoms than those who did not. The study, published in the British Journal of Psychiatry, looked at 134 mothers with post-natal depression. Early recovery is seen to be crucial to limit effects on mother and baby. Post-natal depression is estimated to affect one in eight new mothers. Previous studies have indicated singing can help improve the mental health of older people and those with dementia, but this is the first controlled study of its effect on post-natal depression. The women were placed into three groups: one took part in group singing another took part in in creative play sessions a third group received their usual care, which could include family support, antidepressants or mindfulness The singing workshops saw the mothers learning lullabies and songs from around the world with their babies and creating new songs together about motherhood. And those with moderate to severe symptoms of post-natal depression reported a much faster improvement than mothers in the usual care and play groups. All the groups improved over the 10 weeks, but in the first six weeks the singing group had already reported an average 35% decrease in depressive symptoms. Principal investigator Dr Rosie Perkins said the study, although small, was significant because it was important to tackle the symptoms as quickly as possible. "Post-natal depression is debilitating for mothers and their families, yet our research indicates that for some women something as accessible as singing with their baby could help to speed up recovery at one of the most vulnerable times of their lives," she said. Lead author Dr Daisy Fancourt, from University College London, said singing was another useful therapy to offer women. © 2018 BBC

Keyword: Depression
Link ID: 24506 - Posted: 01.09.2018

By Dina Fine Maron One evening this past fall a patient stumbled into the emergency room at Brigham and Women’s Hospital in Boston. “I don’t feel so…” she muttered, before losing consciousness. Her breathing was shallow and her pupils were pinpoints, typical symptoms of an opioid overdose. Her care team sprang into action. They injected her with 0.4 milligram of naloxone, an overdose antidote—but she remained unresponsive. They next tried one milligram, then two, then four. In total they used 12 milligrams in just five minutes, says Edward Boyer, the physician overseeing her care that night. Yet the patient still had trouble breathing. They put a tube down her throat and hooked her to a ventilator. Twenty minutes later she woke up—angry and in drug withdrawal, but alive. The patient, whose identifying details may have been altered to protect patient confidentiality, had apparently injected herself with a synthetic opioid such as fentanyl right outside of the hospital building. That gave her just enough time to seek help. But many users of synthetic opioids are not so lucky. These drugs, which bear little chemical resemblance to any opioid derived from the opium poppy, are much more powerful than poppy-based heroin and semisynthetic opioids such as oxycodone or hydrocodone. Thus, the standard dose of naloxone employed by first responders (and sold in bystander overdose kits) is often not potent enough to save a synthetic opioid user’s life. © 2018 Scientific American

Keyword: Drug Abuse; Pain & Touch
Link ID: 24505 - Posted: 01.09.2018

By DENISE GRADY One blue surgical drape at a time, the patient disappeared, until all that showed was a triangle of her shaved scalp. “Ten seconds of quiet in the room, please,” said Dr. David J. Langer, the chairman of neurosurgery at Lenox Hill Hospital in Manhattan, part of Northwell Health. Silence fell, until he said, “O.K., I’ll take the scissors.” His patient, Anita Roy, 66, had impaired blood flow to the left side of her brain, and Dr. Langer was about to perform bypass surgery on slender, delicate arteries to restore the circulation and prevent a stroke. The operating room was dark, and everyone was wearing 3-D glasses. Lenox Hill is the first hospital in the United States to buy a device known as a videomicroscope, which turns neurosurgery into an immersive and sometimes dizzying expedition into the human brain. Enlarged on a 55-inch monitor, the stubble on Ms. Roy’s shaved scalp spiked up like rebar. The scissors and scalpel seemed big as hockey sticks, and popped out of the screen so vividly that observers felt an urge to duck. “This is like landing on the moon,” said a neurosurgeon who was visiting to watch and learn. The equipment produces magnified, high-resolution, three-dimensional digital images of surgical sites, and lets everyone in the room see exactly what the surgeon is seeing. The videomicroscope has a unique ability to capture “the brilliance and the beauty of the neurosurgical anatomy,” Dr. Langer said. He and other surgeons who have tested it predict it will change the way many brain and spine operations are performed and taught. “The first time I used it, I told students that this gives them an understanding of why I went into neurosurgery in the first place,” Dr. Langer said. © 2018 The New York Times Company

Keyword: Brain imaging
Link ID: 24504 - Posted: 01.09.2018

By Catherine Offord Neurobiologist John Wood has long been interested in how animals feel pain. His research at University College London (UCL) typically involved knocking out various ion channels important in sensory neuronal function from mouse models and observing the effects. But in the mid-2000s, a peculiar story about a boy in Pakistan opened up a new, and particularly human-centric, research path. The story was relayed by Geoff Woods, a University of Cambridge geneticist. “Geoff had been wandering round Pakistan looking for consanguineous families that had genes contributing to microcephaly,” Wood recalls. During his time there, “somebody came to see him and said that there was a child in the marketplace who was damaging himself for the tourists—and was apparently pain-free.” The boy would regularly stick knives through his arms and walk across burning coals, the stories went. Wood’s group at UCL had just published a paper describing a similarly pain-insensitive phenotype in mice genetically engineered to lack the voltage-gated sodium channel NaV1.7 in pain-sensing neurons, or nociceptors. NaV1.7 controls the passage of sodium ions into the cell—a key step in membrane depolarization and, therefore, a neuron’s capacity to propagate an action potential. Wood’s postdoc, Mohammed Nassar, had shown that mice lacking functional NaV1.7 in their nociceptors exhibited higher-than-normal pain thresholds; they were slower to withdraw a paw from painful stimuli and spent less time licking or biting it after being hurt.1 Having read the study, Cambridge’s Woods reached out to the group in London to discuss whether this same channel could help explain the bizarre behavior of the boy he’d heard about in Pakistan. © 1986-2018 The Scientist

Keyword: Pain & Touch
Link ID: 24503 - Posted: 01.09.2018

Tina Hesman Saey In movies, exploring the body up close often involves shrinking to microscopic sizes and taking harrowing rides through the blood. Thanks to a new virtual model, you can journey through a three-dimensional brain. No shrink ray required. The Society for Neuroscience and other organizations have long sponsored the website BrainFacts.org, which has basic information about how the human brain functions. Recently, the site launched an interactive 3-D brain. A translucent, light pink brain initially rotates in the middle of the screen. With a click of a mouse or a tap of a finger on a mobile device, you can highlight and isolate different parts of the organ. A brief text box then pops up to provide a structure’s name and details about the structure’s function. For instance, the globus pallidus — dual almond-shaped structures deep in the brain — puts a brake on muscle contractions to keep movements smooth. Some blurbs tell how a structure got its name or how researchers figured out what it does. Scientists, for example, have learned a lot about brain function by studying people who have localized brain damage. But the precuneus, a region in the cerebral cortex along the brain’s midline, isn’t usually damaged by strokes or head injuries, so scientists weren’t sure what the region did. Modern brain-imaging techniques that track blood flow and cell activity indicate the precuneus is involved in imagination, self-consciousness and reflecting on memories. |© Society for Science & the Public 2000 - 2018

Keyword: Brain imaging
Link ID: 24502 - Posted: 01.09.2018

by Emilie Reas Functional MRI (fMRI) is one of the most celebrated tools in neuroscience. Because of their unique ability to peer directly into the living brain while an organism thinks, feels and behaves, fMRI studies are often devoted disproportionate media attention, replete with flashy headlines and often grandiose claims. However, the technique has come under a fair amount of criticism from researchers questioning the validity of the statistical methods used to analyze fMRI data, and hence the reliability of fMRI findings. Can we trust those flashy headlines claiming that “scientists have discovered the area of the brain,” or are the masses of fMRI studies plagued by statistical shortcomings? To explore why these studies can be vulnerable to experimental failure, in their new PLOS One study coauthors Henk Cremers, Tor Wager and Tal Yarkoni investigated common statistical issues encountered in typical fMRI studies, and proposed how to avert them moving forward. The reliability of any experiment depends on adequate power to detect real effects and reject spurious ones, which can be influenced by various factors including the sample size (or number of “subjects” in fMRI), how strong the real effect is (“effect size”), whether comparisons are within or between subjects, and the statistical threshold used. To characterize common statistical culprits of fMRI studies, Cremers and colleagues first simulated typical fMRI scenarios before validating these simulations on a real dataset. One scenario simulated weak but diffusely distributed brain activity, and the other scenario simulated strong but localized brain activity (Figure 1). The simulation revealed that effect sizes are generally inflated for weak diffuse, compared to strong localized, activations, especially when the sample size is small. In contrast, effect sizes can actually be underestimated for strong localized scenarios when the sample size is large. Thus, more isn’t always better when it comes to fMRI; the optimal sample size likely depends on the specific brain-behavior relationship under investigation.

Keyword: Brain imaging
Link ID: 24501 - Posted: 01.09.2018

Eric Nyquist for Quanta Magazine Brains, beyond their signature achievements in thinking and problem solving, are paragons of energy efficiency. The human brain’s power consumption resembles that of a 20-watt incandescent lightbulb. In contrast, one of the world’s largest and fastest supercomputers, the K computer in Kobe, Japan, consumes as much as 9.89 megawatts of energy — an amount roughly equivalent to the power usage of 10,000 households. Yet in 2013, even with that much power, it took the machine 40 minutes to simulate just a single second’s worth of 1 percent of human brain activity. Now engineering researchers at the California NanoSystems Institute at the University of California, Los Angeles, are hoping to match some of the brain’s computational and energy efficiency with systems that mirror the brain’s structure. They are building a device, perhaps the first one, that is “inspired by the brain to generate the properties that enable the brain to do what it does,” according to Adam Stieg, a research scientist and associate director of the institute, who leads the project with Jim Gimzewski, a professor of chemistry at UCLA. The device is a far cry from conventional computers, which are based on minute wires imprinted on silicon chips in highly ordered patterns. The current pilot version is a 2-millimeter-by-2-millimeter mesh of silver nanowires connected by artificial synapses. Unlike silicon circuitry, with its geometric precision, this device is messy, like “a highly interconnected plate of noodles,” Stieg said. And instead of being designed, the fine structure of the UCLA device essentially organized itself out of random chemical and electrical processes. All Rights Reserved © 2018

Keyword: Learning & Memory; Robotics
Link ID: 24500 - Posted: 01.08.2018