By Helen Thomson People in a minimally conscious state have been “woken” for a whole week after a brief period of brain stimulation. The breakthrough suggests we may be on the verge of creating a device that can be used at home to help people with disorders of consciousness communicate with friends and family. People with severe brain trauma can fall into a coma. If they begin to show signs of arousal but not awareness, they are said to be in a vegetative state. If they then show fluctuating signs of awareness but cannot communicate, they are described as being minimally consciousness. In 2014, Steven Laureys at the University of Liège in Belgium and his colleagues discovered that 13 people with minimal consciousness and two people in a vegetative state could temporarily show new signs of awareness when given mild electrical stimulation. The people in the trial received transcranial direct current stimulation (tDCS), which uses low-level electrical stimulation to make neurons more or less likely to fire. This was applied once over an area of the brain called the prefrontal cortex, which is involved in “higher” cognitive functions such as consciousness. Soon after, they showed signs of consciousness, including moving their hands or following instructions using their eyes. Two people were even able to answer questions for 2 hours by moving their body, before drifting back into their previous state. © Copyright New Scientist Ltd.

Keyword: Consciousness
Link ID: 23610 - Posted: 05.13.2017

By Reuters People with attention-deficit/hyperactivity disorder are at increased risk of motor-vehicle accidents, but it is significantly reduced when they are taking ADHD medication, a 10-year study finds. The researchers estimate that 1 in 5 of the accidents among more than 2 million people with ADHD during the study period could have been avoided if these individuals had been receiving medication the entire time. “The patients should be aware of the potential risk of [crashes], and seek specific treatment advice from their doctors if they experience difficulties in driving from their condition,” said lead author Zheng Chang, of the Karolinska Institute in Stockholm. Chang said that motor-vehicle crashes kill more than 1.25 million people around the world each year. ADHD is a common disorder with symptoms that include poor sustained attention, impaired impulse control and hyperactivity, he added. Past studies have found that people with ADHD are at an increased risk for crashes and that medication may reduce symptoms and ultimately improve driving skills. To examine the risk of crashes with ADHD and how it is influenced by medication, the researchers analyzed U.S. commercial health insurance claims between 2005 and 2014. They identified 2,319,450 adults with an ADHD diagnosis, half of whom were older than 33. About 1.9 million of them received at least one prescription to treat their ADHD during the study period. © 1996-2017 The Washington Post

Keyword: ADHD; Attention
Link ID: 23609 - Posted: 05.13.2017

by Laura Sanders One of the most pressing and perplexing questions parents have to answer is what to do about screen time for little ones. Even scientists and doctors are stumped. That’s because no one knows how digital media such as smartphones, iPads and other screens affect children. The American Academy of Pediatrics recently put out guidelines, but that advice was based on a frustratingly slim body of scientific evidence, as I’ve covered. Scientists are just scratching the surface of how screen time might influence growing bodies and minds. Two recent studies point out how hard these answers are to get. But the studies also hint that the answers might be important. In the first study, Julia Ma at the University of Toronto and colleagues found that, in children younger than 2, the more time spent with a handheld screen, such as a smartphone or tablet, the more likely the child was to show signs of a speech delay. Ma presented the work May 6 at the 2017 Pediatric Academic Societies Meeting in San Francisco. The team used information gleaned from nearly 900 children’s 18-month checkups. Parents answered a questionnaire about their child’s mobile media use and then filled out a checklist designed to identify heightened risk of speech problems. This checklist is a screening tool that picks up potential signs of trouble; it doesn’t offer a diagnosis of a language delay, points out study coauthor Catherine Birken, a pediatrician at The Hospital for Sick Children in Toronto. Going into the study, the researchers didn’t have expectations about how many of these toddlers were using handheld screens. “We had very little clues, because there is almost no literature on the topic,” Birken says. “There’s just really not a lot there.” |© Society for Science & the Public 2000 - 2017

Keyword: Development of the Brain; Sleep
Link ID: 23608 - Posted: 05.13.2017

By Andy Coghlan Combining multiple tests could help doctors distinguish between two leading causes of cognitive decline at an earlier stage. Being able to separate the earliest signs of Alzheimer’s from another degenerative brain condition called dementia with Lewy bodies (DLB) could be crucial to finding treatments for both kinds of dementia. When someone starts to exhibit mild cognitive impairments, it is often difficult to tell whether these might be the earliest signs of Alzheimer’s or DLB, or just normal age-related declines in cognition. Yet this distinction is vital: so far, despite billions of dollars spent on research, progress towards drugs that stabilise or cure dementia has stalled. Many blame the failure on treating people too late and argue that the same drugs might work better if given a decade or two before symptoms fully develop. Now, Dilman Sadiq at University College London and her colleagues have attempted to rectify this problem by analysing clinical histories, the results of cognitive tests and psychiatric interviews with 429 people originally diagnosed with mild cognitive impairment, who were monitored for up to 14 years. Each person was diagnosed at one UK hospital between 1994 and 2015. Of this group, 107 progressed to Alzheimer’s, 21 to DLB and 164 remained stable with mild cognitive impairment. The rest developed a mixture of other conditions. Sadiq’s team used their findings to identify a variety of tests and symptom profiles that appear to predict which condition a person might get at the earliest stage of the disease. © Copyright New Scientist Ltd.

Keyword: Alzheimers
Link ID: 23607 - Posted: 05.13.2017

By FERRIS JABR Con Slobodchikoff and I approached the mountain meadow slowly, obliquely, softening our footfalls and conversing in whispers. It didn’t make much difference. Once we were within 50 feet of the clearing’s edge, the alarm sounded: short, shrill notes in rapid sequence, like rounds of sonic bullets. We had just trespassed on a prairie-dog colony. A North American analogue to Africa’s meerkat, the prairie dog is trepidation incarnate. It lives in subterranean societies of neighboring burrows, surfacing to forage during the day and rarely venturing more than a few hundred feet from the center of town. The moment it detects a hawk, coyote, human or any other threat, it cries out to alert the cohort and takes appropriate evasive action. A prairie dog’s voice has about as much acoustic appeal as a chew toy. French explorers called the rodents petits chiens because they thought they sounded like incessantly yippy versions of their pets back home. On this searing summer morning, Slobodchikoff had taken us to a tract of well-trodden wilderness on the grounds of the Museum of Northern Arizona in Flagstaff. Distressed squeaks flew from the grass, but the vegetation itself remained still; most of the prairie dogs had retreated underground. We continued along a dirt path bisecting the meadow, startling a prairie dog that was peering out of a burrow to our immediate right. It chirped at us a few times, then stared silently. “Hello,” Slobodchikoff said, stooping a bit. A stout bald man with a scraggly white beard and wine-dark lips, Slobodchikoff speaks with a gentler and more lilting voice than you might expect. “Hi, guy. What do you think? Are we worth calling about? Hmm?” Slobodchikoff, an emeritus professor of biology at Northern Arizona University, has been analyzing the sounds of prairie dogs for more than 30 years. Not long after he started, he learned that prairie dogs had distinct alarm calls for different predators. Around the same time, separate researchers found that a few other species had similar vocabularies of danger. What Slobodchikoff claimed to discover in the following decades, however, was extraordinary: Beyond identifying the type of predator, prairie-dog calls also specified its size, shape, color and speed; the animals could even combine the structural elements of their calls in novel ways to describe something they had never seen before. No scientist had ever put forward such a thorough guide to the native tongue of a wild species or discovered one so intricate. Prairie-dog communication is so complex, Slobodchikoff says — so expressive and rich in information — that it constitutes nothing less than language.

Keyword: Language; Evolution
Link ID: 23606 - Posted: 05.12.2017

Amy Maxmen Cells that prune connections between neurons in babies’ brains as they grow are thought to have a role in autism spectrum disorder. Now, a study suggests that the number and behaviour of these cells — called microglia — vary in boys and girls, a finding that could help to explain why many more boys are diagnosed with autism and related disorders. Donna Werling, a neurogeneticist at the University of California, San Francisco, and her colleagues found that genes associated with microglia are more active in male brains than in female brains in the months before birth. “This suggests there is something fundamentally different about male and female brain development,” she says. The research, to be presented on 13 May at the International Meeting for Autism Research in San Francisco, California, is still preliminary. Very little is known about how microglial trimming behaviour affects brain development. But the study by Werling’s team “is the kind of work that makes you say ‘Wow, this is really interesting, and we should take it seriously’”, says Kevin Pelphrey, a neuroscientist at Yale School of Medicine in New Haven, Connecticut. There are two to five times many males with autism as females. Although the disorder — whose cause remains elusive — is widely acknowledged to be underdiagnosed in girls, psychiatrists agree that there is a significant disparity between the numbers of male and female cases. It suggests that biological differences between the sexes are involved. © 2017 Macmillan Publishers Limited,

Keyword: Autism; Glia
Link ID: 23605 - Posted: 05.12.2017

By Lindzi Wessel You’ve probably heard that your sense of smell isn’t that great. After all, compared with a dog or even a mouse, the human olfactory system doesn’t take up that much space. And when was the last time you went sniffing the ground alongside your canine companion? But now, in a new review published today in Science, neuroscientist John McGann of Rutgers University in New Brunswick, New Jersey, argues that the myth of the nonessential nose is a huge mistake—one that has led scientists to neglect research in a critical and mysterious part of our minds. Science checked in with McGann to learn more about why he thinks our noses know more than we realize. Q: Many of us assume our sense of smell is terrible, especially compared with other animals. Where did this idea come from? A: I traced part of this history back to 19th century [anatomist and] anthropologist Paul Broca, who was interested in comparing brains across lots of different animals. Compared to the olfactory bulbs [the first stop for smell signals in the brain], the rest of the human brain is very large. So if you look at whole brains, the bulbs look like these tiny afterthoughts; if you look at a mouse or a rat, the olfactory bulb seems quite big. You can almost forgive Broca for thinking that they didn't matter because they look so small comparatively. Broca believed that a key part of having free will was not being forced to do things by odors. And he thought of smell as this almost dirty, animalistic thing that compelled behaviors—it compelled animals to have sex with each other and things like that. So he put humans in the nonsmeller category—not because they couldn't smell, but because we had free will and could decide how to respond to smells. The idea also got picked up by Sigmund Freud, who then thought of smell as an animalistic thing that had to be left behind as a person grew into a rational adult. So you had in psychology, philosophy, and anthropology all these different pathways leading to presumption that humans didn't have a good sense of smell. © 2017 American Association for the Advancement of Scienc

Keyword: Chemical Senses (Smell & Taste)
Link ID: 23604 - Posted: 05.12.2017

By GINA KOLATA Researchers have traced the cause of a baffling brain disorder to a surprising source: a particular type of bacteria living in the gut. Scientists increasingly suspect that the body’s vast community of bacteria — the microbiome — may play a role in the development of a wide variety of diseases, from obesity to perhaps even autism. The new study, published on Wednesday in Nature, is among the first to suggest convincingly that these bacteria may initiate disease in seemingly unrelated organs, and in completely unexpected ways. Researchers “need to be thinking more broadly about the indirect role of the microbiome” in influencing even diseases that have no obvious link to the gut, said Dr. David Relman, professor of microbiology and immunology at Stanford. The researchers studied hereditary cerebral cavernous malformations — blood-filled bubbles that protrude from veins in the brain and can leak blood or burst at any time. The findings do not point to a cure, but they do suggest a way to prevent these brain defects in children who inherit a mutated gene that can cause them. Researchers warned, though, that it is too soon to say whether the potential treatment — antibiotics, followed by a fecal transplant — will work. “Caution, caution, caution,” urged Dr. Mark Ginsberg, a professor of medicine at the University of California, San Diego, who was not involved in the new study. Still, he added, “The findings are very convincing.” When Dr. Mark Kahn, professor of cardiovascular medicine at the University of Pennsylvania’s Perelman School of Medicine, began this work, the microbiome was the last thing on his mind. © 2017 The New York Times Company

Keyword: Stroke; Epilepsy
Link ID: 23603 - Posted: 05.11.2017

By Agata Blaszczak-Boxe We tend to be worse at telling apart faces of other races than those of our own race, studies have found. Now research shows some people are completely blind to features that make other-race faces distinct. Such an impairment could have important implications for eyewitness testimony in situations involving other-race suspects. The ability to distinguish among members of one's own race varies wildly: some people can tell strangers apart effortlessly, whereas others cannot even recognize the faces of their own family and friends (a condition known as prosopagnosia). Psychologist Lulu Wan of the Australian National University and her colleagues wanted to quantify the distribution of abilities for recognizing other-race faces. They asked 268 Caucasians born and raised in Australia to memorize a series of six Asian faces and conducted the same experiment, involving Caucasian faces, with a group of 176 Asians born and raised in Asia who moved to Australia to attend university. In 72 trials, every participant was then shown sets of three faces and had to point to the one he or she had learned in the memorization task. The authors found that 26 Caucasian and 10 Asian participants—8 percent of the collective study population—did so badly on the test that they met the criteria for clinical-level impairment. “We know that we are poor at recognizing other-race faces,” says Jim Tanaka, a professor of psychology at the University of Victoria in British Columbia, who was not involved in the research. “This study shows just how poor some people are.” Those individuals “would be completely useless in terms of their legal value as an eyewitness,” says study co-author Elinor McKone, a professor of psychology at the Australian National University. The world's legal systems do not, however, take into account individual differences in other-race face recognition, she notes. © 2017 Scientific American

Keyword: Attention
Link ID: 23602 - Posted: 05.11.2017

Have you ever found yourself craving a steak or a burger? The brain controls our feelings of hunger and also determines the types of nutrients we should be seeking out. Not much is understood about the brain’s regulation of nutrient-specific hunger, but in a new study published in Science, researchers identified the brain cells in fruit flies that regulate protein hunger and were able to control those cells, affecting what the animals ate. The study, was funded by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health. To study protein hunger, a team of researchers led by Mark Wu, M.D., Ph.D., associate professor of neurology at Johns Hopkins University in Baltimore, starved flies of yeast (the animal’s protein source) for one week. Afterwards, they discovered that the flies ate more yeast and less sugar than flies that ate a control diet. “Flies have been a great model system for brain research so we can learn a lot about how our own brain circuits work by peeking inside the heads of flies,” said Janet He, Ph.D., program director at the NINDS. “A better understanding of the basic mechanisms that regulate the consumption of different nutrients may help to provide clues to addressing the obesity epidemic.” Using novel genetic tools, Dr. Wu’s team identified a specific circuit, a set of brain cells that communicate with one another, which controls protein-seeking behavior. When the circuit was stimulated, flies ate more yeast than normal. In contrast, when the researchers turned off the circuit, the flies ate less yeast. The cells in the circuit were more active, which was demonstrated by increased firing activity, when the flies were starved of yeast. Turning the circuit on or off did not affect the animals’ general hunger or thirst.

Keyword: Obesity
Link ID: 23601 - Posted: 05.11.2017

By Sandra Lamb Each night before “Greg” goes to bed he brushes and flosses his teeth. Then he double-checks the instructions on the dark brown bottle his nurse gave him before he unscrews the cap and tips five drops of a light-amber, oily liquid onto a spoon. The brew, glistening from the light of the bathroom fixture, is tasteless and has no odor he can detect. But it’s chock-full of bacteria. He sloshes the substance around in his mouth and swallows. Greg hopes that while he sleeps the foreign microbes will wage war with other organisms in his gut, changing that environment to ultimately help him manage some of the post-traumatic stress disorder (PTSD) symptoms that cloud his mind and riddle his days and nights with nightmares, flashbacks, thoughts of suicide and irrational responses to stressful events. The bacteria he is swallowing, his doctors tell him, “may help reduce symptoms of stress.” Each drop of Greg's brew is filled with millions of Lactobacillus reuteri, a bacterium isolated and derived from human breast milk. The Denver VA Hospital orders the substance and prescribes it as part of a PTSD clinical trial involving 40 veterans who either receive the bacteria or a placebo mix of sunflower oil and other inactive substances. (The bacterium is also currently used to treat a dental condition called chronic periodontitis because it has been shown to help fight inflammation.) © 2017 Scientific American

Keyword: Stress; Obesity
Link ID: 23600 - Posted: 05.10.2017

Ian Sample Science editor A landmark project to map the wiring of the human brain from womb to birth has released thousands of images that will help scientists unravel how conditions such as autism, cerebral palsy and attention deficit disorders arise in the brain. The first tranche of images come from 40 newborn babies who were scanned in their sleep to produce stunning high-resolution pictures of early brain anatomy and the intricate neural wiring that ferries some of the earliest signals around the organ. The initial batch of brain scans are intended to give researchers a first chance to analyse the data and provide feedback to the senior scientists at King’s College London, Oxford University and Imperial College London who are leading the Developing Human Connectome Project, which is funded by €15m (£12.5m) from the EU. The images show the intricate neural wiring that ferries some of the earliest signals around the brain. Hundreds of thousands more images will be released in the coming months and years. Most will come from a thousand sleeping babies, but another 500 have had their brains scanned while still in the womb. “The challenge is that you are imaging one person inside another person and both of them move,” said Jo Hajnal, professor of imaging science at King’s College London, who developed new MRI technology for the project. Taking brain scans of sleeping babies is hard enough. At the start of the project in 2013, more than 10% of the scans failed when babies woke up in the middle of the two to three hour procedure. Now the babies are fed and prepared for their scans at their mother’s side before they are carried to the scanner. To cut the odds of the babies waking, scientists tweaked the scanner software to stop it making sudden noises.

Keyword: Development of the Brain; Brain imaging
Link ID: 23599 - Posted: 05.10.2017

By Jane C. Hu New evidence suggests that the earliest traces of a language can stay with us into adulthood, even if we no longer speak or understand the language itself. And early exposure also seems to speed the process of relearning it later in life. In the new study, recently published in Royal Society Open Science, Dutch adults were trained to listen for sound contrasts in Korean. Some participants reported no prior exposure to the language; others were born in Korea and adopted by Dutch families before the age of six. All participants said they could not speak Korean, but the adoptees from Korea were better at distinguishing between the contrasts and more accurate in pronouncing Korean sounds. “Language learning can be retained subconsciously, even if conscious memories of the language do not exist,” says Jiyoun Choi, postdoctoral fellow at Hanyang University in Seoul and lead author of the study. And it appears that just a brief period of early exposure benefits learning efforts later; when Choi and her collaborators compared the results of people adopted before they were six months old with results of others adopted after 17 months, there were no differences in their hearing or speaking abilities. “It's exciting that these effects are seen even among adults who were exposed to Korean only up to six months of age—an age before which babbling emerges,” says Janet Werker, a professor of psychology at the University of British Columbia, who was not involved with the research. Remarkably, what we learn before we can even speak stays with us for decades. © 2017 Scientific American,

Keyword: Language; Development of the Brain
Link ID: 23598 - Posted: 05.10.2017

Sara Reardon Tom Insel, former director of the US National Institute of Mental Health, is searching for new ways of addressing mental illness. Sixteen months after leaving the US National Institute of Mental Health (NIMH) for Google’s health sciences division, psychiatrist Tom Insel is on the move again. The former NIMH director, who left Google on 5 May, is starting his own company. Insel’s group, called Mindstrong, will try to infer a person’s mental-health status by analysing the way they use smartphones. Insel stepped down as NIMH director in December 2015 in order to start a mental-health program called Verily within Google’s Life Sciences group. One of the division’s goals overlaps with that of Mindstrong's: Verily intends to build tools, which could include smartphone apps or computer programs, that can recognize characteristics of mental illness using a method known as “digital phenotyping”. The method analyses factors such as a user’s word choice in communication, voice patterns when talking to digital assistants, their physical movements and location data to determine their state of mind. If a smartphone could recognize when its owner was feeling suicidal, for instance, it could potentially intervene by providing resources or alerting others. © 2017 Macmillan Publishers Limited

Keyword: Depression; Schizophrenia
Link ID: 23597 - Posted: 05.10.2017

By Michael Price Unless you’re colorblind, you probably have a pretty good idea of what red, green, and blue are. Yet those labels are arbitrary divisions of the color spectrum; there’s no definitive point where the wavelengths of light we call orange turn into red. So cognitive scientists have long wondered whether we learn our labels from our culture or inherit them from our biology. Now, a study finds that infants see red, yellow, green, blue, and purple as different color categories, suggesting that at least some distinctions may be hardwired. “I find it really compelling,” says Michael Webster, a psychologist who studies visual perception at the University of Nevada in Reno, who wasn’t involved in the study. “This isn’t going to immediately change anyone’s mind. But it’s another piece in the puzzle, and it’s a very nice piece.” Scientists can’t just ask a newborn what it knows, so they use a trick known as “infant looking time” to figure out what’s in babies’ brains. The idea is that an infant’s gaze will linger on something unfamiliar for longer than something familiar, giving researchers a window into what babies expect—and what surprises them. Applying this to color research, scientists led by Anna Franklin, a perception and cognition researcher at the University of Sussex in the United Kingdom, showed 179 infants aged 46 months 14 different swaths of color, each from a different part of the color wheel. Researchers showed one swath several times before displaying a hue from the next range over. If the infants looked at the new hue longer than the previous one, experimenters concluded that the babies considered it a different color. © 2017 American Association for the Advancement of Science

Keyword: Vision; Development of the Brain
Link ID: 23596 - Posted: 05.09.2017

By Daniel Shalev Maddie* couldn't stop crying. The first few days after her stroke, it had made sense. She had led a charmed retirement, with annual trips across the country, time with family and an active life. Now everything was in flux. A week before, Maddie, who was in her late 70s, had woken up unable to use half of her body. Her husband called an ambulance, and a diagnosis was reached within hours. Maddie had suffered a blockage in the blood vessels supplying her brain stem, affecting the pons, a region that conducts messages from higher centers of control and consciousness down to her body. At the hospital, she began to undergo a rush of frightening tests to evaluate the cause of her stroke and the risk of having another. She figured it made sense to cry. A few days later, when Maddie was transferred from the stroke unit to the rehabilitation service, she was feeling more hopeful. Her risk of further strokes had been minimized with drugs to regulate her blood pressure, cholesterol and clotting. She could hear that her speech, initially slurred, returning to clarity. On the stroke unit, the emphasis had been on stabilization, but in rehabilitation, the goal was improvement. Maddie felt ready to work on her recovery. Even with the hope of rehabilitation, though, the tears continued. Maddie cried when her husband came in and when he left. She cried during therapy meetings and medical updates. She cried through eating and bathing. The only time she did not weep was while she slept. Most oddly, Maddie cried even when she did not feel sad. On the stroke unit, the crying had been annoying. In rehabilitation, it was downright disruptive. Maddie's therapy sessions were impeded by bouts of sobbing that invariably led the befuddled therapists to cut short their work with her. © 2017 Scientific American

Keyword: Emotions
Link ID: 23595 - Posted: 05.09.2017

Shelby Putt How did humans get to be so smart, and when did this happen? To untangle this question, we need to know more about the intelligence of our human ancestors who lived 1.8 million years ago. It was at this point in time that a new type of stone tool hit the scene and the human brain nearly doubled in size. Some researchers have suggested that this more advanced technology, coupled with a bigger brain, implies a higher degree of intelligence and perhaps even the first signs of language. But all that remains from these ancient humans are fossils and stone tools. Without access to a time machine, it’s difficult to know just what cognitive features these early humans possessed, or if they were capable of language. Difficult – but not impossible. Now, thanks to cutting-edge brain imaging technology, my interdisciplinary research team is learning just how intelligent our early tool-making ancestors were. By scanning the brains of modern humans today as they make the same kinds of tools that our very distant ancestors did, we are zeroing in on what kind of brainpower is necessary to complete these tool-making tasks. The stone tools that have survived in the archaeological record can tell us something about the intelligence of the people who made them. Even our earliest human ancestors were no dummies; there is evidence for stone tools as early as 3.3 million years ago, though they were probably making tools from perishable items even earlier. © 2010–2017, The Conversation US, Inc.

Keyword: Evolution; Brain imaging
Link ID: 23594 - Posted: 05.09.2017

By Michael Le Page In some cultures, it’s traditional for elders to smoke grass, a practice said to help them pass on tribal knowledge. It turns out that they might just be onto something. Teenagers who toke perform less well on memory and attention tasks while under the influence. But low doses of the active ingredient in cannabis, THC, might have the opposite effect on the elderly, reversing brain ageing and restoring learning and memory – at least according to studies of mice. “We repeated these experiments many times,” says team leader Andreas Zimmer at the University of Bonn, Germany. “It’s a very robust and profound effect.” Zimmer’s team has been studying the mammalian endocannabinoid system, which is involved in balancing out our bodies’ response to stress. THC affects us by mimicking similar molecules in this system, calming us down. The researchers discovered that mice with genetic mutations that stop this endocannabinoid system from working properly age faster than normal mice, and show more cognitive decline. This made Zimmer wonder if stimulating the endocannabinoid system in elderly mice might have the opposite effect. To find out, the team gave young (2-month-old), middle-aged (12-month-old) and elderly (18-month-old) mice a steady dose of THC. The amount they received was too small to give them psychoactive effects. After a month, the team tested the mice’s ability to perform cognitive tasks, such as finding their way around mazes, or recognising other individuals. © Copyright Reed Business Information Ltd.

Keyword: Drug Abuse; Development of the Brain
Link ID: 23593 - Posted: 05.09.2017

By Kerry Grens In June of 2014, Pablo Meyer went to Rockefeller University in New York City to give a talk about open data. He leads the Translational Systems Biology and Nanobiotechnology group at IBM Research and also guides so-called DREAM challenges, or Dialogue for Reverse Engineering Assessments and Methods. These projects crowdsource the development of algorithms from open data to make predictions for all manner of medical and biological problems—for example, prostate cancer survival or how quickly ALS patients’ symptoms will progress. Andreas Keller, a neuroscientist at Rockefeller, was in the audience that day, and afterward he emailed Meyer with an offer and a request. “He said, ‘We have this data set, and we don’t model,’” recalls Meyer. “‘Do you think you could organize a competition?’” The data set Keller had been building was far from ordinary. It was the largest collection of odor perceptions of its kind—dozens of volunteers, each having made 10 visits to the lab, described 476 different smells using 19 descriptive words (including sweet, urinous, sweaty, and warm), along with the pleasantness and intensity of the scent. Before Keller’s database, the go-to catalog at researchers’ disposal was a list of 10 odor compounds, described by 150 participants using 146 words, which had been developed by pioneering olfaction scientist Andrew Dravnieks more than three decades earlier. Meyer was intrigued, so he asked Keller for the data. Before launching a DREAM challenge, Meyer has to ensure that the raw data provided to competitors do indeed reflect some biological phenomenon. In this case, he needed to be sure that algorithms could determine what a molecule might smell like when only its chemical characteristics were fed in. There were more than 4,800 molecular features for each compound, including structural properties, functional groups, chemical compositions, and the like. “We developed a simple linear model just to see if there’s a signal there,” Meyer says. “We were very, very surprised we got a result. We thought there was a bug.” © 1986-2017 The Scientist

Keyword: Chemical Senses (Smell & Taste); Robotics
Link ID: 23592 - Posted: 05.09.2017

Bruce Bower Fossils of a humanlike species with some puzzlingly ancient skeletal quirks are surprisingly young, its discoverers say. It now appears that this hominid, dubbed Homo naledi, inhabited southern Africa close to 300,000 years ago, around the dawn of Homo sapiens. H. naledi achieved worldwide acclaim in 2015 as a possibly pivotal player in the evolution of the human genus, Homo. Retrieved from an underground chamber in South Africa, fossils of this species were thought to be anywhere from 900,000 to at least 1.8 million years old (SN: 8/6/16, p. 12). A younger age for H. naledi resolves one mystery about these cave fossils. It doesn’t, however, answer questions about how long ago the species first appeared and when it died out. What is now known is that H. naledi bodies somehow ended up in Dinaledi Chamber, part of South Africa’s Rising Star cave system, between 236,000 and 335,000 years ago, an international team reports in one of three papers published May 9 in eLife. Paleoanthropologist Lee Berger of the University of the Witwatersrand in Johannesburg headed the team. Geoscientist Paul Dirks of James Cook University in Townsville, Australia, directed the dating effort. In the first paper, two methods of measuring the concentration of natural uranium and other radioactive elements, and damage caused by those elements over time, provided key age estimates for three H. naledi teeth. A thin sheet of rock deposited by flowing water just above the fossils was also dated. |© Society for Science & the Public 2000 - 201

Keyword: Evolution
Link ID: 23591 - Posted: 05.09.2017