By Sarah Kaplan The ancient Greeks spoke of a mythological society composed entirely of warrior women. The medieval traveler John Mandeville wrote of a place whose female rulers "never would suffer man to dwell amongst them." "Paradise Island," home of Wonder Woman, was a feminist utopia where no one with a Y chromosome was allowed. Sadly, those places only exist in fiction. But something like them does exist in the real world. It's in a wetland in rural Ohio. And it's full of salamanders. "They’re pretty incredible," said Robert Denton, a biologist at Ohio State who studies an unusual group of salamander species that literally don't need men. These creatures – all female – reproduce by cloning themselves. To keep their gene pool diverse, they sometimes "steal" sperm left behind on trees and leaves by male salamanders of other species and incorporate that DNA into their offspring. Most sexually reproducing organisms have two sets of chromosomes to make up their genome – one from each parent. But one of these strange salamanders can have between two and five times that much genetic material lying in wait within her cells. It's as if they have multiple genomes to fall back on, and that's made them incredibly successful. "Polyploid" salamanders have been around some 6 million years, Denton said — far longer than most other animal species that reproduce asexually. Since a lack of diversity means having a smaller arsenal of genetic variation to fall back on when living conditions change, these groups usually go extinct relatively quickly. © 1996-2016 The Washington Post

Keyword: Sexual Behavior; Evolution
Link ID: 22176 - Posted: 05.04.2016

by Susan Milius There’s nothing like a guy doing all the child care to win female favor, even among giant water bugs. Thumbnail-sized Appasus water bugs have become an exemplar species for studying paternal care. After mating, females lay eggs on a male’s back and leave him to swim around for weeks tending his glued-on load. For an A. major water bug, lab tests show an egg burden can have the sweet side of attracting more females, researchers in Japan report May 4 in Royal Society Open Science. Given a choice of two males, females strongly favored, and laid more eggs on, the one already hauling around 10 eggs rather than the male that researchers had scraped eggless. Females still favored a well-egged male even when researchers offered two males that a female had already considered, but with their egg-carrying roles switched from the previous encounter. That formerly spurned suitor this time triumphed. A similar preference, though not as clear-cut, showed up in the slightly smaller and lighter A. japonicus giant water bug. “We conclude that sexual selection plays an important role in the maintenance of elaborate paternal care,” says study coauthor Shin-ya Ohba of Nagasaki University. © Society for Science & the Public 2000 - 2016

Keyword: Sexual Behavior; Evolution
Link ID: 22175 - Posted: 05.04.2016

By Emily Benson Baby birds are sometimes known to shove their siblings out of the nest to gain their parents’ undivided attention, but barn owl chicks appear to be more altruistic. Scientists recorded the hissing calls of hungry and full barn owl nestlings (Tyto alba, pictured), then played the sounds back to single chicks settled in nests stocked with mice. The young owls that heard the squawks of their hungry kin delayed eating each rodent by an average of half an hour; those that heard cries indicating their invisible nest-mate was full ate the mice more quickly. The findings suggest that barn owl chicks give hungrier siblings a chance to eat first even when the nest is full of food, the researchers will report in an upcoming issue of Behavioral Ecology and Sociobiology. So is it true altruism? Maybe not. Nestlings may share food in exchange for help with grooming or to get the first crack at a later meal, the team says, suggesting a possible ulterior motive. © 2016 American Association for the Advancement of Science

Keyword: Evolution
Link ID: 22174 - Posted: 05.04.2016

Laura Sanders Iron, says aging expert Naftali Raz, is like the Force. It can be good or bad, depending on the context. When that context is the human brain, though, scientists wrangle over whether iron is a dark force for evil or a bright source of support. Some iron is absolutely essential for the brain. On that, scientists agree. But recent studies suggest to some researchers that too much iron, and the chemical reactions that ensue, can be dangerous or deadly, especially to nerve cells in the vulnerable brain area that deteriorates with Parkinson’s disease. Yet other work raises the possibility that those cells die because of lack of iron, rather than too much. “There are a lot of surprises in this field,” says iron biologist Nancy Andrews of Duke University. The idea that too much iron is dangerous captivates many researchers, including analytical neurochemist Dominic Hare of the University of Technology Sydney. “All of life is a chemical reaction,” he says, “so the start of disease is a chemical reaction as well.” And as Raz points out, reactions involving iron are both life-sustaining and dangerous. “Iron is absolutely necessary for conducting the very fundamental business in every cell,” says Raz, of Wayne State University in Detroit. It helps produce energy-storing ATP molecules. And that’s a dirty job, throwing off dangerous free radicals that can cause cellular mayhem as energy is made. But those free radicals are not the most worrisome aspect of iron, Hare believes. “The reaction that is much more dangerous is the reaction you get when iron and dopamine come together,” he says. © Society for Science & the Public 2000 - 2016.

Keyword: Parkinsons
Link ID: 22173 - Posted: 05.03.2016

By Sarah Kaplan Scientists have known for a while that stereotypes warp our perceptions of things. Implicit biases — those unconscious assumptions that worm their way into our brains, without our full awareness and sometimes against our better judgment — can influence grading choices from teachers, split-second decisions by police officers and outcomes in online dating. We can't even see the world without filtering it through the lens of our assumptions, scientists say. In a study published Monday in the journal Nature Neuroscience, psychologists report that the neurons that respond to things such as sex, race and emotion are linked by stereotypes, distorting the way we perceive people's faces before that visual information even reaches our conscious brains. "The moment we actually glimpse another person ... [stereotypes] are biasing that processing in a way that conforms to our already existing expectations," said Jonathan Freeman, a psychology professor at New York University and one of the authors of the report. Responsibility lies in two far-flung regions of the brain: the orbital frontal cortex, which rests just above the eyes and is responsible for rapid visual predictions and categorizations, and the fusiform cortex, which sits in the back of the brain and is involved in recognizing faces. When Freeman and his co-author, Ryan Stolier, had 43 participants look at images of faces in a brain scanner, they noticed that neurons seemed to be firing in similar patterns in both parts of the brain, suggesting that information from each part was influencing the other.

Keyword: Attention; Emotions
Link ID: 22172 - Posted: 05.03.2016

By Jennifer Jolly Every January for the past decade, Jessica Irish of Saline, Mich., has made the same New Year’s Resolution: to “cut out late night snacking and lose 30 pounds.” Like millions of Americans, Ms. Irish, 31, usually makes it about two weeks. But this year is different. “I’ve already lost 18 pounds,” she said, “and maintained my diet more consistently than ever. Even more amazing — I rarely even think about snacking at night anymore.” Ms. Irish credits a new wearable device called Pavlok for doing what years of diets, weight-loss programs, expensive gyms and her own willpower could not. Whenever she takes a bite of the foods she wants to avoid, like chocolate or Cheez-Its, she uses the Pavlok to give herself a lightning-quick electric shock. “Every time I took a bite, I zapped myself,” she said. “I did it five times on the first night, two times on the second night, and by the third day I didn’t have any cravings anymore.” As the name suggests, the $199 Pavlok, worn on the wrist, uses the classic theory of Pavlovian conditioning to create a negative association with a specific action. Next time you smoke, bite your nails or eat junk food, one tap of the device or a smartphone app will deliver a shock. The zap lasts only a fraction of a second, though the severity of the shock is up to you. It can be set between 50 volts, which feels like a strong vibration, and 450 volts, which feels like getting stung by a bee with a stinger the size of an ice pick. (By comparison, a police Taser typically releases about 50,000 volts.) Other gadgets and apps dabble in behavioral change by way of aversion therapy, such as the $49 MotivAider that is worn like a pager, or the $99 RE-vibe wristband. Both can be set to vibrate at specific intervals as a reminder of a habit to break or a goal to reach. The $80 Lumo Lift posture coach is a wearable disk that vibrates when you slouch. The $150 Spire clip-on sensor tracks physical activity and state of mind by detecting users’ breathing patterns. If it detects you’re stressed or anxious, it vibrates or sends a notification to your smartphone to take a deep breath. © 2016 The New York Times Company

Keyword: Learning & Memory
Link ID: 22171 - Posted: 05.03.2016

By Julia Shaw In the last couple of years memory science has really upped its game. I generally write about social processes that can change our memories, but right now I can’t help but get excited that memory science is getting an incredible new toy to play with. A toy that I believe will revolutionise how we talk about, and deal with, memory. This not-so-new sounding, but totally-newly-applied, neuroscience toy is ultrasound. Ultrasound is also called sonography and is essentially a type of ‘medical sonar’. It has revolutionized medicine since the 1940s, giving us the ability to look into the body in a completely safe way (without leaving icky radiation behind, like xrays). Beyond predicting whether your baby shower will be blue or pink, lesser known applications of ultrasound include the ability to essentially burn and destroy cells inside your body. As such, it has been successfully used to do surgery without making any cuts into the human body. This is a technique that has been used to remove cancerous cells while not affecting any of the surrounding tissue, and without any of the side-effects associated with other kinds of cancer treatment. This is referred to by scientist Yoav Medan as focused ultrasound. If you are unfamiliar with this, you need to watch this TED talk. Non-invasive procedures like this are the future of surgery. Non-invasive procedures are also the future of neuroscience. It is at this point that we find ourselves at the application of this astonishing science to memory research. © 2016 Scientific American

Keyword: Brain imaging; Learning & Memory
Link ID: 22170 - Posted: 05.03.2016

By Karen Weintraub The four members of Asperger’s Are Us decided a long time ago that their main goal would be to amuse themselves. But after nearly a decade of laughing and writing punch lines together, Asperger’s Are Us, which is probably the only comedy troupe made up of people on the autism spectrum, is on the cusp of comedic success. A documentary about the group premiered at the SXSW conference in Austin in March and was recently sold to Netflix. The troupe is also preparing for its first national tour this summer. Comedy might be a surprising choice for someone with Asperger’s syndrome, since stereotypically, people with autism are generally regarded as socially awkward loners. But the four men in the group bonded at summer camp 11 years ago, when one was a counselor and the other three were campers, and are clearly great friends. An “Aspergers Are Us” performance from 2011. Talking recently via Skype, Noah Britton, the former counselor, settles giant black rabbit ears onto his head. Jack Hanke, another member of the troupe, dons his favorite sombrero – the black one he took with him to Oxford University during his recent junior year abroad – accessorized with a red sombrero on top. They slip into their usual banter when asked what they thought of the film, named for the group, which will be shown publicly for the first time on Friday at the Somerville Theater outside of Boston. “I liked the four weird guys in it,” Mr. Britton said. “It was better than ‘Jaws 2,’ but not as good as ‘Jaws 3,’” Mr. Hanke insisted. “I found it kind of annoying myself,” added Ethan Finlan, another member of the group. The fourth member, who changed his first name to New Michael to distinguish himself from his father, Michael Ingemi, didn’t want to join the call. © 2016 The New York Times Company

Keyword: Autism
Link ID: 22169 - Posted: 05.03.2016

By GINA KOLATA Danny Cahill stood, slightly dazed, in a blizzard of confetti as the audience screamed and his family ran on stage. He had won Season 8 of NBC’s reality television show “The Biggest Loser,” shedding more weight than anyone ever had on the program — an astonishing 239 pounds in seven months. When he got on the scale for all to see that evening, Dec. 8, 2009, he weighed just 191 pounds, down from 430. Dressed in a T-shirt and knee-length shorts, he was lean, athletic and as handsome as a model. “I’ve got my life back,” he declared. “I mean, I feel like a million bucks.” Mr. Cahill left the show’s stage in Hollywood and flew directly to New York to start a triumphal tour of the talk shows, chatting with Jay Leno, Regis Philbin and Joy Behar. As he heard from fans all over the world, his elation knew no bounds. But in the years since, more than 100 pounds have crept back onto his 5-foot-11 frame despite his best efforts. In fact, most of that season’s 16 contestants have regained much if not all the weight they lost so arduously. Some are even heavier now. Yet their experiences, while a bitter personal disappointment, have been a gift to science. A study of Season 8’s contestants has yielded surprising new discoveries about the physiology of obesity that help explain why so many people struggle unsuccessfully to keep off the weight they lose. Kevin Hall, a scientist at a federal research center who admits to a weakness for reality TV, had the idea to follow the “Biggest Loser” contestants for six years after that victorious night. The project was the first to measure what happened to people over as long as six years after they had lost large amounts of weight with intensive dieting and exercise. © 2016 The New York Times Company

Keyword: Obesity
Link ID: 22168 - Posted: 05.02.2016

Patricia Neighmond Hoping to keep your mental edge as you get older? Look after your heart, a recent analysis suggests, and your brain will benefit, too. A research team led by Hannah Gardener, an epidemiologist at the University of Miami, analyzed a subset of data from the Northern Manhattan Study, a large, ongoing study of risk factors for stroke among whites, blacks and Hispanics living in the Washington Heights neighborhood of New York City. The scientists wanted to see how people in their 60s and 70s would do on repeated tests of memory and mental acuity six years later — and, specifically, what sort of subtle differences a heart-healthy lifestyle might make to the brain, beyond the prevention of strokes. Their findings appear in a recent issue of the Journal of the American Heart Association. In this particular study, the researchers started with more than a thousand people who'd had their cardiovascular health assessed using measures that the American Heart Association has dubbed Life's Simple 7. These seven factors known to benefit the heart and blood vessels include maintaining a normal body weight and good nutrition, not smoking, getting exercise regularly and keeping blood pressure, cholesterol and blood sugar levels under control. To measure thinking skills, Gardener's team used a variety of tests of memory, judgement, the ability to plan, mental quickness and other sorts of problem solving. The results were striking: Across all demographic groups, the people who had higher scores on the measures of cardiovascular health did better on the mental tests than those who scored low. © 2016 npr

Keyword: Alzheimers
Link ID: 22167 - Posted: 05.02.2016

By Scott Barry Kaufman "Just because a diagnosis [of ADHD] can be made does not take away from the great traits we love about Calvin and his imaginary tiger friend, Hobbes. In fact, we actually love Calvin BECAUSE of his ADHD traits. Calvin’s imagination, creativity, energy, lack of attention, and view of the world are the gifts that Mr. Watterson gave to this character." -- The Dragonfly Forest In his 2004 book "Creativity is Forever", Gary Davis reviewed the creativity literature from 1961 to 2003 and identified 22 reoccurring personality traits of creative people. This included 16 "positive" traits (e.g., independent, risk-taking, high energy, curiosity, humor, artistic, emotional) and 6 "negative" traits (e.g., impulsive, hyperactive, argumentative). In her own review of the creativity literature, Bonnie Cramond found that many of these same traits overlap to a substantial degree with behavioral descriptions of Attention Deficit Hyperactive Disorder (ADHD)-- including higher levels of spontaneous idea generation, mind wandering, daydreaming, sensation seeking, energy, and impulsivity. Research since then has supported the notion that people with ADHD characteristics are more likely to reach higher levels of creative thought and achievement than people without these characteristics (see here, here, here, here, here, here, here, here, here, and here). Recent research by Darya Zabelina and colleagues have found that real-life creative achievement is associated with the ability to broaden attention and have a “leaky” mental filter-- something in which people with ADHD excel. © 2016 Scientific American

Keyword: ADHD
Link ID: 22166 - Posted: 05.02.2016

Symptoms of depression that steadily increase over time in older age could indicate early signs of dementia, scientists have said. Other patterns of symptoms, such as chronic depression, appear not to be linked, a study found. Dutch researchers looked at different ways depression in older adults progressed over time and how this related to any risk. They concluded worsening depression may signal the condition is taking hold. The research, published in The Lancet Psychiatry, followed more than 3,000 adults aged 55 and over living in the Netherlands. All had depression but no symptoms of dementia at the start of the study. Dr M Arfan Ikram of the Erasmus University Medical Center in Rotterdam said depressive symptoms that gradually increase over time appear to be a better predictor of dementia later in life than other paths of depression. "There are a number of potential explanations, including that depression and dementia may both be symptoms of a common underlying cause, or that increasing depressive symptoms are on the starting end of a dementia continuum in older adults," he said. Only the group whose symptoms of depression increased over time were found to be at increased risk of dementia - about one in five of people (55 out of 255) in this group developed dementia. Others who had symptoms that waxed and waned or stayed the same were not at increased risk. For example, in those who experienced low but stable levels of depression, around 10% went on to develop dementia. The exact nature of depression on dementia risk remains unknown. © 2016 BBC

Keyword: Depression; Alzheimers
Link ID: 22165 - Posted: 05.02.2016

By ERICA GOODE Horses snooze in their stalls. Fish take their 40 winks floating in place. Dogs can doze anywhere, anytime. And even the lowly worm nods off now and then. All animals, most scientists agree, engage in some form of sleep. But the stages of sleep that characterize human slumber had until now been documented only in mammals and birds. A team of researchers in Germany announced in a report published on Thursday, however, that they had found evidence of similar sleep stages in a lizard: specifically, the bearded dragon, or Pogona vitticeps, a reptile native to Australia and popular with pet owners. Recordings from electrodes implanted in the lizards’ brains showed patterns of electrical activity that resembled what is known as slow-wave sleep and another pattern resembling rapid eye movement, or REM, sleep, a stage of deep slumber associated with brain activity similar to that of waking. Some researchers had argued that these stages were of relatively recent origin in evolutionary terms because they had not been found in more primitive animals like amphibians, fish, reptiles other than birds, and other creatures with backbones. But the new finding, said Gilles Laurent, director of the department of neural systems at the Max Planck Institute for Brain Research and the principal author of the study, “increases the probability that sleep evolved in all these animals from a common ancestor.” He added that it also raised the possibility that staged sleep evolved even earlier and that some version of it might exist in animals like amphibians or fish. The report appeared in Thursday’s issue of the journal Science. Other researchers said the study could help scientists understand more about the purpose and mechanisms of sleep. But the finding, they added, is bound to generate more controversy about whether the resting state of primitive animals is really the same as sleep, and whether the brain activity seen in a lizard can be compared to that in mammals. © 2016 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 22164 - Posted: 04.30.2016

Tina Hesman Saey To rewrite an Alanis Morissette song, the brain has a funny way of waking you up (and putting you to sleep). Isn’t it ionic? Some scientists think so. Changes in ion concentrations, not nerve cell activity, switch the brain from asleep to awake and back again, researchers report in the April 29 Science. Scientists knew that levels of potassium, calcium and magnesium ions bathing brain cells changed during sleep and wakefulness. But they thought neurons — electrically active cells responsible for most of the brain’s processing power — drove those changes. Instead, the study suggests, neurons aren’t the only sandmen or roosters in the brain. “Neuromodulator” brain chemicals, which pace neuron activity, can bypass neurons altogether to directly wake the brain or lull it to sleep by changing ion concentrations. Scientists hadn’t found this direct connection between ions and sleep and wake before because they were mostly focused on what neurons were doing, says neuroscientist Maiken Nedergaard, who led the study. She got interested in sleep after her lab at the University of Rochester in New York found a drainage system that washes the brain during sleep (SN: 11/16/13, p. 7).When measuring changes in the fluid between brain cells, Nedergaard and colleagues realized that ion changes followed predictable patterns: Potassium ion levels are high when mice (and presumably people) are awake, and drop during sleep. Calcium and magnesium ions follow the opposite pattern; they are higher during sleep and lower when mice are awake. © Society for Science & the Public 2000 - 2016

Keyword: Sleep
Link ID: 22163 - Posted: 04.30.2016

By BENEDICT CAREY Listening to music may make the daily commute tolerable, but streaming a story through the headphones can make it disappear. You were home; now you’re at your desk: What happened? Storytelling happened, and now scientists have mapped the experience of listening to podcasts, specifically “The Moth Radio Hour,” using a scanner to track brain activity. In a paper published Wednesday by the journal Nature, a research team from the University of California, Berkeley, laid out a detailed map of the brain as it absorbed and responded to a story. Widely dispersed sensory, emotional and memory networks were humming, across both hemispheres of the brain; no story was “contained” in any one part of the brain, as some textbooks have suggested. The team, led by Alexander Huth, a postdoctoral researcher in neuroscience, and Jack Gallant, a professor of psychology, had seven volunteers listen to episodes of “The Moth” — first-person stories of love, loss, betrayal, flight from an abusive husband, and more — while recording brain activity with an M.R.I. machine. Sign Up for the Science Times Newsletter Every week, we'll bring you stories that capture the wonders of the human body, nature and the cosmos. Using novel computational methods, the group broke down the stories into units of meaning: social elements, for example, like friends and parties, as well as locations and emotions . They found that these concepts fell into 12 categories that tended to cause activation in the same parts of people’s brains at the same points throughout the stories. They then retested that model by seeing how it predicted M.R.I. activity while the volunteers listened to another Moth story. Would related words like mother and father, or times, dates and numbers trigger the same parts of people’s brains? The answer was yes. © 2016 The New York Times Company

Keyword: Language; Brain imaging
Link ID: 22162 - Posted: 04.30.2016

By Andy Coghlan “I’ve become resigned to speaking like this,” he says. The 17-year old boy’s mother tongue is Dutch, but for his whole life he has spoken with what sounds like a French accent. “This is who I am and it’s part of my personality,” says the boy, who lives in Belgium – where Dutch is an official language – and prefers to remain anonymous. “It has made me stand out as a person.” No matter how hard he tries, his speech sounds French. About 140 cases of foreign accent syndrome (FAS) have been described in scientific studies, but most of these people developed the condition after having a stroke. In the UK, for example, a woman in Newcastle who’d had a stroke in 2006 woke up with a Jamaican accent. Other British cases include a woman who developed a Chinese accent, and another who acquired a pronounced French-like accent overnight following a bout of cerebral vasculitis. But the teenager has had the condition from birth, sparking the interest of Jo Verhoeven of City University London and his team. Scans revealed that, compared with controls, the flow of blood to two parts of the boy’s brain were significantly reduced. One of these was the prefrontal cortex of the left hemisphere – a finding unsurprising to the team, as it is known to be associated with planning actions including speech. © Copyright Reed Business Information Ltd.

Keyword: Language
Link ID: 22161 - Posted: 04.30.2016

By n. r. kleinfield IT BEGAN WITH what she saw in the bathroom mirror. On a dull morning, Geri Taylor padded into the shiny bathroom of her Manhattan apartment. She casually checked her reflection in the mirror, doing her daily inventory. Immediately, she stiffened with fright. Huh? What? She didn’t recognize herself. She gazed saucer-eyed at her image, thinking: Oh, is this what I look like? No, that’s not me. Who’s that in my mirror? This was in late 2012. She was 69, in her early months getting familiar with retirement. For some time she had experienced the sensation of clouds coming over her, mantling thought. There had been a few hiccups at her job. She had been a nurse who climbed the rungs to health care executive. Once, she was leading a staff meeting when she had no idea what she was talking about, her mind like a stalled engine that wouldn’t turn over. “Fortunately I was the boss and I just said, ‘Enough of that; Sally, tell me what you’re up to,’” she would say of the episode. Certain mundane tasks stumped her. She told her husband, Jim Taylor, that the blind in the bedroom was broken. He showed her she was pulling the wrong cord. Kept happening. Finally, nothing else working, he scribbled on the adjacent wall which cord was which. Then there was the day she got off the subway at 14th Street and Seventh Avenue unable to figure out why she was there. So, yes, she had had inklings that something was going wrong with her mind. She held tight to these thoughts. She even hid her suspicions from Mr. Taylor, who chalked up her thinning memory to the infirmities of age. “I thought she was getting like me,” he said. “I had been forgetful for 10 years.”

Keyword: Alzheimers
Link ID: 22160 - Posted: 04.30.2016

By PAM BELLUCK Alzheimer’s disease can seem frightening, mysterious and daunting. There are still a lot of unknowns about the disease, which afflicts more than five million Americans. Here are answers to some common questions: Sometimes I forget what day it is or where I put my glasses. Is this normal aging, or am I developing Alzheimer’s? Just because you forgot an item on your grocery list doesn’t mean you are developing dementia. Most people have occasional memory lapses, which increase with age. The memory problems that characterize warning signs of Alzheimer’s are usually more frequent, and they begin to interfere with safe or competent daily functioning: forgetting to turn off the stove, leaving home without being properly dressed or forgetting important appointments. Beyond that, the disease usually involves a decline in other cognitive abilities: planning a schedule, following multistep directions, carrying out familiar logistical tasks like balancing a checkbook or cooking a meal. It can also involve mood changes, agitation, social withdrawal and feelings of confusion, and can even affect or slow a person’s gait. How is Alzheimer’s diagnosed? Diagnosing Alzheimer’s usually involves a series of assessments, including memory and cognitive tests. Clinicians will also do a thorough medical work-up to determine whether the thinking and memory problems can be explained by other diagnoses, such as another type of dementia, a physical illness or side effects from a medication. Brain scans and spinal taps may also be conducted to check for corroborating evidence like the accumulation of amyloid, the hallmark protein of Alzheimer’s, in the brain or spinal fluid. The cause is unknown for most cases. Fewer than 5 percent of cases are linked to specific, rare gene mutations. Those are usually early-onset cases that develop in middle age. © 2016 The New York Times Company

Keyword: Alzheimers
Link ID: 22159 - Posted: 04.30.2016

By Adam Bear It happens hundreds of times a day: We press snooze on the alarm clock, we pick a shirt out of the closet, we reach for a beer in the fridge. In each case, we conceive of ourselves as free agents, consciously guiding our bodies in purposeful ways. But what does science have to say about the true source of this experience? In a classic paper published almost 20 years ago, the psychologists Dan Wegner and Thalia Wheatley made a revolutionary proposal: The experience of intentionally willing an action, they suggested, is often nothing more than a post hoc causal inference that our thoughts caused some behavior. The feeling itself, however, plays no causal role in producing that behavior. This could sometimes lead us to think we made a choice when we actually didn’t or think we made a different choice than we actually did. But there’s a mystery here. Suppose, as Wegner and Wheatley propose, that we observe ourselves (unconsciously) perform some action, like picking out a box of cereal in the grocery store, and then only afterwards come to infer that we did this intentionally. If this is the true sequence of events, how could we be deceived into believing that we had intentionally made our choice before the consequences of this action were observed? This explanation for how we think of our agency would seem to require supernatural backwards causation, with our experience of conscious will being both a product and an apparent cause of behavior. In a study just published in Psychological Science, Paul Bloom and I explore a radical—but non-magical—solution to this puzzle. © 2016 Scientific America

Keyword: Consciousness
Link ID: 22158 - Posted: 04.30.2016

Ian Sample Science editor Scientists have created an “atlas of the brain” that reveals how the meanings of words are arranged across different regions of the organ. Like a colourful quilt laid over the cortex, the atlas displays in rainbow hues how individual words and the concepts they convey can be grouped together in clumps of white matter. “Our goal was to build a giant atlas that shows how one specific aspect of language is represented in the brain, in this case semantics, or the meanings of words,” said Jack Gallant, a neuroscientist at the University of California, Berkeley. No single brain region holds one word or concept. A single brain spot is associated with a number of related words. And each single word lights up many different brain spots. Together they make up networks that represent the meanings of each word we use: life and love; death and taxes; clouds, Florida and bra. All light up their own networks. Described as a “tour de force” by one researcher who was not involved in the study, the atlas demonstrates how modern imaging can transform our knowledge of how the brain performs some of its most important tasks. With further advances, the technology could have a profound impact on medicine and other fields. “It is possible that this approach could be used to decode information about what words a person is hearing, reading, or possibly even thinking,” said Alexander Huth, the first author on the study. One potential use would be a language decoder that could allow people silenced by motor neurone disease or locked-in syndrome to speak through a computer. © 2016 Guardian News and Media Limited

Keyword: Language; Brain imaging
Link ID: 22157 - Posted: 04.28.2016