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Dean Burnett Every now and then, you see news reports of people with incredible memories, able to recall every single thing from their life at a moment’s notice. Initially, it may sound like an incredibly useful ability. No more searching for your car keys that you had in your hand minutes ago, no more desperately stalling for time as you flounder to remember the name of the casual acquaintance who’s just said hello to you, no more taking notes at all. Why would you need to? It’s no wonder it pops up often in pop culture. Indeed, there are many people who can demonstrate incredible memory prowess, having trained their memories to be as efficient and thorough as possible via useful and approved techniques, in order to compete in memory sports, which are an actual thing. Clearly, for some people at least, there is potential to greatly boost the brain’s ability to store and recall information to well above average levels. Ben Carson even claimed to be able to induce this with a simple bit of surgery (which is utterly wrong) What’s far more rare are reports of people who do this without even trying, without having to learn and train with an endless series of mnemonics and so on. Like one of Marvel’s mutants discovering a hitherto unexpected super power, some people seem to be born with seemingly-infallible memories. There are a number of terms that are used to describe such abilities. Photographic memory, eidetic memory, Hyperthymesia, Highly Superior Autobiographical Memory, perfect recall, there are a number of labels to choose from when discussing formidable memory prowess.
Keyword: Learning & Memory
Link ID: 23549 - Posted: 04.28.2017
New research from the National Institutes of Health found that pairing the antidepressant amitriptyline with drugs designed to treat central nervous system diseases, enhances drug delivery to the brain by inhibiting the blood-brain barrier in rats. The blood-brain barrier serves as a natural, protective boundary, preventing most drugs from entering the brain. The research, performed in rats, appeared online April 27 in the Journal of Cerebral Blood Flow and Metabolism. Although researchers caution that more studies are needed to determine whether people will benefit from the discovery, the new finding has the potential to revolutionize treatment for a whole host of brain-centered conditions, including epilepsy, stroke,human amyotrophic lateral sclerosis (ALS), depression, and others. The results are so promising that a provisional patent application has been filed for methods of co-administration of amitriptyline with central nervous system drugs. According to Ronald Cannon, Ph.D., staff scientist at NIH’s National Institute of Environmental Health Sciences (NIEHS), the biggest obstacle to efficiently delivering drugs to the brain is a protein pump called P-glycoprotein. Located along the inner lining of brain blood vessels, P-glycoprotein directs toxins and pharmaceuticals back into the body’s circulation before they pass into the brain. To get an idea of how P-glycoprotein works, Cannon said to think of the protein as a hotel doorman, standing in front of a revolving door at a lobby entrance. A person who is not authorized to enter would get turned away, being ushered back around the revolving door and out into the street.
Link ID: 23548 - Posted: 04.28.2017
By Olga Mecking When I was a new mother, the parenting books I read encouraged me to treat child-rearing like a science project. I was told to pay particular attention to my baby’s developing brain, which was malleable and awe-inspiring, but also fragile. I thought I was supposed to provide an optimal environment for my children’s brain growth, because didn’t they deserve the very best? And the earlier I started the better, because the stakes were high. If I failed, my children could develop any number of mental disorders. At least, that was my impression after having read nearly every parenting book on the market. I also expected to spontaneously and intuitively know how to care for my babies. But I didn’t have a clue, and articles like these made me feel like a failure. Was it so unnatural for a mother to want time to herself, or to not want to become one with her baby? It seemed that way, but Jan Macvarish, author of the recent book, “Neuroparenting: The Expert Invasion of Family Life,” disagrees. Macvarish is deeply concerned about this ultra-scientific approach to parenting, in part because it reduces everything to the mother-child relationship. “To talk about parenting in this way is untruthful because this isn’t the way that any child is raised,” she says. “There are always other people involved.” And she’s right. I felt that I was solely responsible for my children’s well-being, and that pressure started to get to me. What kind of mother was I if I couldn’t take care of my babies’ developing brains properly? © 1996-2017 The Washington Post
Keyword: Development of the Brain
Link ID: 23547 - Posted: 04.28.2017
By NICHOLAS BAKALAR Diabetes may be bad for the brain, especially if you are overweight. Researchers studied 50 overweight and 50 normal weight people in the early stages of Type 2 diabetes. All had been given a diagnosis within the previous five years. They compared both groups with 50 healthy control subjects. The scientists performed M.R.I. examinations of their brains and psychological tests of memory, reaction time and planning. Those with diabetes scored worse than the healthy controls on tests of memory and reaction times. M.R.I. scans revealed significant differences in brain areas related to memory, planning and the visual processing of information. Compared with the controls, those with Type 2 diabetes had more severe thinning of the cortex and more white matter abnormalities. Overweight people with diabetes had more brain deterioration than diabetic people of normal weight. Are these changes reversible? Probably not, according to a co-author, Dr. Donald C. Simonson of Brigham and Women’s Hospital in Boston. “When structural changes are seen on an M.R.I. scan, the processes leading up to them have probably been going on for years,” he said. “On the positive side, patients who maintain good control of their diabetes do seem to have a slower rate of deterioration.” The findings were published in Diabetologia. © 2017 The New York Times Company
Jon Hamilton Tiny, 3-D clusters of human brain cells grown in a petri dish are providing hints about the origins of disorders like autism and epilepsy. An experiment using these cell clusters — which are only about the size of the head of a pin — found that a genetic mutation associated with both autism and epilepsy kept developing cells from migrating normally from one cluster of brain cells to another, researchers report in the journal Nature. "They were sort of left behind," says Dr. Sergiu Pasca, an assistant professor of psychiatry and behavioral sciences at Stanford. And that type of delay could be enough to disrupt the precise timing required for an actual brain to develop normally, he says. The clusters — often called minibrains, organoids or spheroids — are created by transforming skin cells from a person into neural stem cells. These stem cells can then grow into structures like those found in the brain and even form networks of communicating cells. Brain organoids cannot grow beyond a few millimeters in size or perform the functions of a complete brain. But they give scientists a way to study how parts of the brain develop during pregnancy. "One can really understand both a process of normal human brain development, which we frankly don't understand very well, [and] also what goes wrong in the brain of patients affected by diseases," says Paola Arlotta, a professor of stem cell and regenerative biology at Harvard who was not involved in the cell migration study. Arlotta is an author of a second paper in Nature about creating a wide variety of brain cells in brain organoids. © 2017 npr
By KAREN BARROW The World Health Organization estimates that more than 50 million people worldwide have some form of epilepsy, a neurological disorder that is characterized by recurring episodes of seizure. While seizures come in various forms, those with epilepsy cope with similar issues: social stigma, complex treatment options and a feeling of powerlessness. Here, eight men, women and children discuss what it’s like to live with epilepsy. Denise L. Pease, an assistant comptroller for New York City, began having complex partial seizures after a car accident in which she suffered a traumatic brain injury. But because Ms. Pease lives alone, it wasn’t until a relative saw her having a tonic-clonic seizure, what used to be known as a grand mal seizure, that she realized she had developed epilepsy. Tonic-clonic seizures typically involve the whole body and can be very dramatic. Ms. Pease began to notice that she would get a strange taste in her mouth before a seizure, so whenever that happened she made sure she was seated in a safe location and waited for the seizure to pass. This sensation of an oncoming seizure, called an aura, is common among people with epilepsy. After eight years of trying different medications to control her epilepsy, Ms. Pease is happy to be back at work and no longer lives in fear of an imminent seizure. Ms. Pease is hopeful that she will soon be able to drive, and she continues to plan for her future. “When you have epilepsy, you have to be your own advocate,” she said. Sallie Gallagher’s son, Michael, started having complex partial seizures at age 4. This type of seizure doesn’t cause the full-body twitching associated with tonic-clonic seizure, but it can cause a person to start to act strangely or be completely unaware of his surroundings. © 2017 The New York Times Company
Link ID: 23544 - Posted: 04.27.2017
By Sam Wong Six years ago, a chimpanzee had the bright idea to use moss to soak up water, then drink from it, and seven others soon learned the trick. Three years later, researchers returned to the site to see if the practice had persisted to become part of the local chimp culture. They now report that the technique has continued to spread, and it’s mostly been learned by relatives of the original moss-spongers. This adds to earlier evidence that family ties are the most important routes for culture to spread in animals. After the first report of chimps using moss as a sponge in Budongo Forest, Uganda, researchers rarely saw the behaviour again, and wondered whether chimps still knew how to do it. So they set up an experiment, providing moss and leaves at the clay pit where the chimps had demonstrated the technique before. Then they watched to see whether chimpanzees would use leaves – a more common behaviour – or moss to soak up the mineral-rich water from the pit. The eight original moss-spongers all used moss again during the experiment, and so did another 15 chimps, showing the practice had become more widespread. The researchers wondered what factors influenced which individuals adopted it: were they connected socially, or through families, for instance? © Copyright Reed Business Information Ltd.
By NICHOLAS BAKALAR A new study links diet soft drinks to an increased risk for stroke and dementia. Researchers studied more than 4,000 people over 45 who had filled out food-frequency questionnaires and had periodic health examinations between 1991 and 2001. The scientists tracked their health over the next 10 years and found 97 cases of stroke and 81 cases of dementia. The study, in the journal Stroke, found that compared with those who did not drink diet soda, people who drank one to six artificially sweetened drinks a week had twice the risk of stroke. There were similar, although weaker, associations for dementia risk. The reasons for the link remain unknown. The study adjusted for age, sex, education, physical activity, diabetes, smoking and many other characteristics that might affect the risks. But the senior author, Dr. Sudha Seshadri, a professor of neurology at Boston University School of Medicine, said that there were additional variables the study could not address. For example, she said, people might have switched to diet soda because they already had cardiovascular problems. Still, she added, there are health benefits associated with some drinks, like tea or coffee, “but not with soda of any kind, either diet or not.” © 2017 The New York Times Company
Bruce Bower NEW ORLEANS — A relatively small brain can pack a big evolutionary punch. Consider Homo naledi, a famously puzzling fossil species in the human genus. Despite having a brain only slightly larger than a chimpanzee’s, H. naledi displays key humanlike neural features, two anthropologists reported April 20 at the annual meeting of the American Association of Physical Anthropologists. Those brain characteristics include a region corresponding to Broca’s area, which spans parts of the right and left sides of the brain in present-day people. The left side is typically involved in speech and language. “It looks like Homo naledi’s brain evolved a huge amount of shape change that supported social emotions and advanced communication of some type,” said Shawn Hurst of Indiana University Bloomington, who presented the new findings. “We can’t say for sure whether that included language.” Frontal brain locations near Broca’s area contribute to social emotions such as empathy, pride and shame. As interactions within groups became more complex in ancient Homo species, neural capacities for experiencing social emotions and communicating verbally blossomed, Hurst suspects. Scientists don’t know how long ago H. naledi inhabited Africa’s southern tip. If H. naledi lived 2 million or even 900,000 years ago, as some researchers have suggested (SN: 8/6/16, p. 12), humanlike brains with a language-related area would be shocking. A capacity for language is thought to have emerged in Homo over the last few hundred thousand years at most. |© Society for Science & the Public 2000 - 2017.
Link ID: 23541 - Posted: 04.26.2017
By Debra W. Soh The reasons behind why people are gay, straight, or bisexual have long been a source of public fascination. Indeed, research on the topic of sexual orientation offers a powerful window into understanding human sexuality. The Archives of Sexual Behavior recently published a special edition devoted to research in this area, titled “The Puzzle of Sexual Orientation.” One study, conducted by scientists at the University of Lethbridge in Alberta, Canada, offers compelling, cross-cultural evidence that common genetic factors underlie same-sex, sexual preference in men. In southern Mexico, individuals who are biologically male and sexually attracted to men are known as muxes. They are recognized as a third gender: Muxe nguiiu tend to be masculine in their appearance and behavior, while muxe gunaa are feminine. In Western cultures, they would be considered gay men and transgender women, respectively. Several correlates of male androphilia — biological males who are sexually attracted to men — have been shown across different cultures, which is suggestive of a common biological foundation among them. For example, the fraternal birth order effect—the phenomenon whereby male androphilia is predicted by having a higher number of biological older brothers—is evident in both Western and Samoan cultures. Interestingly, in Western society, homosexual men, compared with heterosexual men, tend to recall higher levels of separation anxiety — the distress resulting from being separated from major attachment figures, like one’s primary caregiver or close family members. Research in Samoa has similarly demonstrated that third-gender fa’afafine—individuals who are feminine in appearance, biologically male, and attracted to men—also recall greater childhood separation anxiety when compared with heterosexual Samoan men. Thus, if a similar pattern regarding separation anxiety were to be found in a third, disparate culture—in the case, the Istmo region of Oaxaca, Mexico—it would add to the evidence that male androphilia has biological underpinnings. © 2017 Scientific American
By CATHERINE SAINT LOUIS In her 30s, Sophie Marat, now 42, used to record herself reading poetry aloud, then play it back to hear if she sounded like a woman. Ms. Marat, who is transgender, had spent years trying to remake her voice in private by speaking in a higher pitch but ultimately felt that her efforts were hopeless. “I was feeling like changing my voice to match my gender identity was almost impossible,” she said. “It was terrible.” Ms. Marat’s transition from male to female has been a gradual evolution. She had come out to friends and family back home in Mexico, then began to wear skirts to work as a software engineer in Manhattan. Still, her confidence would falter with everyday tasks like ordering takeout. “It was really painful to speak on the phone,” she said, “because they would reply, ‘O.K., sir.’” That was before she started her weekly sessions with a voice therapist at New York University’s speech-language-hearing clinic, one of a growing number of programs that cater to transgender clients seeking to retrain their voices. Just as some transgender women and men choose to take hormones or have surgery, or choose neither, some seek to feminize or masculinize their voices. Many say they want a voice that matches their appearance or that the change allows them to escape unwanted attention. There’s also a growing recognition among health professionals who have transgender patients that altering one’s voice can improve quality of life and reduce distress. After eight months, she had raised her pitch, worked on moving her resonance forward and finishing phrases with an open ending, rather than bluntly. “This isn’t just a sidebar,” said Sandy Hirsch, a Seattle-based speech language pathologist who was a co-author of the pioneering textbook on transgender voice and communication therapy. “It’s an integral part of care for transgender people as they transition.” © 2017 The New York Times Company
By Knvul Sheikh Scientists have known for decades that what we eat can change the balance of microbes in our digestive tracts. Choosing between a BLT sandwich or a yogurt parfait for lunch can increase the populations of some types of bacteria and diminish others—and as their relative numbers change they secrete different substances, activate different genes and absorb different nutrients. And those food choices are probably a two-way street. Gut microbes have also been shown to influence diet and behavior as well as anxiety, depression, hypertension and a variety of other conditions. But exactly how these trillions of tiny guests—collectively called the microbiome—influence our decisions on which foods to stuff into our mouths has been a mystery. Now neuroscientists have found specific types of gut flora help a host animal detect which nutrients are missing in food, and then finely titrate how much of those nutrients the host really needs to eat. “What the bacteria do for appetite is kind of like optimizing how long a car can run without needing to add more petrol to the tank,” says senior author Carlos Ribeiro, who studies the eating behaviors of Drosophila melanogaster, a type of fruit fly, at Champalimaud Center for the Unknown in Lisbon. In a paper published Tuesday in PLoS Biology Ribeiro and his team demonstrated how the microbiome influences drosophila’s nutritional decisions. First, they fed one group of flies a sucrose solution containing all the necessary amino acids. Another group got a mix that had some of the amino acids needed to make protein but lacked essential amino acids that the host cannot synthesize by itself. For a third group of flies, the scientists removed essential amino acids from the food one by one to determine which was being detected by the microbiome. © 2017 Scientific American,
Link ID: 23538 - Posted: 04.26.2017
By Thomas MacMillan “Time” is the most common noun in the English language, Dean Buonomano tells us on the first page of his new book, Your Brain Is a Time Machine: The Neuroscience and Physics of Time. But our despite fixation with time, and its obvious centrality in our lives, we still struggle to fully understand it. From a psychology perspective, for instance, time seems to flow by, sometimes slowly — like when we’re stuck in line at the DMV — and sometimes quickly — like when we’re lost in an engrossing novel. But from a physics perspective, time may be simply another dimension in the universe, like length, height, or width. Buonomano, a professor of neuroscience at UCLA, lays out the latest, best theories about how we understand time, illuminating a fundamental aspect of being human. The human brain, he writes, is a time machine that allows us to mentally travel backward and forward, to plan for the future and agonizingly regret that past like no other animal. And, he argues, our brains are time machines like clocks are time machines: constantly tracking the passage of time, whether it’s circadian rhythms that tell us when to go to sleep, or microsecond calculations that allow us to the hear the difference between “They gave her cat-food” and “They gave her cat food.” In an interview with Science of Us, Buonomano spoke about planning for the future as a basic human activity, the limits of be-here-now mindfulness, and the inherent incompatibility between physicists’ and neuroscientists’ understanding of the nature of time. I finished reading your book late last night and went to bed sort of planning our interview today, and then woke up at about 3:30 a.m. ready to do the interview, with my head full of insistent thoughts about questions that I should ask you. So was that my brain being a — maybe malfunctioning — time machine? I think this is consistent with the notion that the brain is an organ that’s future-oriented. As far as survival goes, the evolutionary value of the brain is to act in the present to ensure survival in the future, whether survival is figuring out a good place to get food, or doing an interview, I suppose. ! © Invalid Date, New York Media LLC
By Daniel Barron Earlier this month, JAMA Psychiatry published a land-breaking editorial. A group of psychiatrists led by David Ross described how and why post-traumatic stress disorder (PTSD) should be clinically evaluated from a neuroscience framework. The fact that this editorial was published in one of psychiatry’s leading journals is no small feat. Psychiatry houses a large and powerful contingency that argues neuroscience has little clinical relevance. The relevance of neuroscience to psychiatry was the subject of a recent Op-Ed debate in the New York Times: “There’s Such a Thing as Too Much Neuroscience” was rebutted with “More Neuroscience, Not Less.” This specific debate—and the dense politics as a whole—exists because competing frameworks are vying for competing funding, a conflict that pre-dates Freud’s departure from neurology. That the relevance of neuroscience to psychiatry is still questioned is blatantly outlandish: what organ do psychiatrists treat if not the brain? And what framework could possibly be more relevant than neuroscience to understanding brain dysfunction? In his editorial, Ross tactfully presented his case for neuroscience, describing the obvious choice for a clinical framework as one “perspective,” making a delicate intellectual curtsey while supporting his case with data. Ross discussed five “key neuroscience themes” (read: lines of evidence from burgeoning sub-fields) relevant to understanding and treating PTSD: fear conditioning, dysregulated circuits, memory reconsolidation, and epigenetic and genetic considerations. Each theme accounts for the diverse biological, psychological and social factors involved in PTSD—which is to say, these factors all have some affect on the brain mechanisms. Most importantly, Ross describes how a mechanistic approach allows clinicians to trace the specific causes of PTSD to specific treatments that can target those causes. © 2017 Scientific American,
By NICHOLAS BAKALAR Drinking sugary beverages is associated with markers of accelerated aging and early signs of Alzheimer’s disease, a new study reports. Researchers used data on more than 4,000 people over 30, examining their brains with M.R.I. and measuring memory with psychological tests. All completed well-validated food frequency questionnaires. Sugary beverage intake is an indirect measure of how much sugar we get in our diets, which is difficult to measure precisely. The authors defined “sugary beverage” to include sodas as well as fruit juices, which may contain added sugars. The study, in Alzheimer’s & Dementia, found that on average, the more sugary drinks consumed, the lower the total brain volume and the lower the scores on memory tests. Brain shrinkage is tied to an increased risk of Alzheimer’s disease. Compared with those who drank no sugary drinks, those who drank one or two a day had a reduced brain volume equivalent to 1.6 years of normal aging, and lower memory scores equivalent to 5.8 years of aging. Those who drank more than two had decreased brain volume equivalent to two years of normal aging and lower memory scores by the equivalent of 11 years. The researchers controlled for diabetes, blood pressure, cholesterol, smoking and many other health and behavioral characteristics. “Although we can’t prove cause and effect, these data suggest that we should be cautious about drinking sugary beverages,” said the lead author, Matthew P. Pase, a senior research fellow at Boston University. “They’re empty calories that contribute to weight gain and metabolic disease.” © 2017 The New York Times Company
By Virginia Morell Humpback whales are known for their operatic songs that carry across the seas. Their calves, however, whisper, uttering soft squeaks and grunts to their mothers (which you can hear above). Now, a new study suggests that loud calf voices can also attract some unwanted visitors: male humpbacks, who might separate the pair by trying to mate with the mother, and killer whales, who dine on young humpbacks. To record their sounds, scientists placed temporary tagging devices on eight humpback whale mothers and calves in the Exmouth Gulf off Western Australia, where the young whales spend months suckling to gain enough weight for their annual migrations to the Antarctic or Arctic. After listening to the recordings, scientists say the calves’ careful whispers are not cries for food, as previously thought. Instead, they may help them stay in close contact with their mothers when swimming. And, say researchers, writing today in Functional Ecology, the low decibel sounds help keep would-be predators away from the “nursery.” © 2017 American Association for the Advancement of Science
Keyword: Animal Communication
Link ID: 23534 - Posted: 04.26.2017
By NICK WINGFIELD SEATTLE — Zoran Popović knows a thing or two about video games. A computer science professor at the University of Washington, Dr. Popović has worked on software algorithms that make computer-controlled characters move realistically in games like the science-fiction shooter “Destiny.” But while those games are entertainment designed to grab players by their adrenal glands, Dr. Popović’s latest creation asks players to trace lines over fuzzy images with a computer mouse. It has a slow pace with dreamy music that sounds like the ambient soundtrack inside a New Age bookstore. The point? To advance neuroscience. Since November, thousands of people have played the game, “Mozak,” which uses common tricks of the medium — points, leveling up and leader boards that publicly rank the performance of players — to crowdsource the creation of three-dimensional models of neurons. The Center for Game Science, a group at the University of Washington that Dr. Popović oversees, developed the game in collaboration with the Allen Institute for Brain Science, a nonprofit research organization founded by Paul Allen, the billionaire co-founder of Microsoft, that is seeking a better understanding of the brain. Dr. Popović had previously received wide attention in the scientific community for a puzzle game called “Foldit,” released nearly a decade ago, that harnesses the skills of players to solve riddles about the structure of proteins. The Allen Institute’s goal of cataloging the structure of neurons, the cells that transmit information throughout the nervous system, could one day help researchers understand the roots of neurodegenerative diseases like Alzheimer’s and Parkinson’s and their treatment. Neurons come in devilishly complex shapes and staggering quantities — about 100 million and 87 billion in mouse and human brains, both of which players can work on in Mozak. © 2017 The New York Times Company
Keyword: Brain imaging
Link ID: 23533 - Posted: 04.25.2017
Doing moderate exercise several times a week is the best way to keep the mind sharp if you're over 50, research suggests. Thinking and memory skills were most improved when people exercised the heart and muscles on a regular basis, a review of 39 studies found. This remained true in those who already showed signs of cognitive decline. Taking up exercise at any age was worthwhile for the mind and body, the Australian researchers said. Exercises such as T'ai Chi were recommended for people over the age of 50 who couldn't manage other more challenging forms of exercise, the study in the British Journal of Sports Medicine said. Physical activity has long been known to reduce the risk of a number of diseases, including type-2 diabetes and some cancers, and it is thought to play a role in warding off the brain's natural decline as we enter middle age. The theory is that through exercise the brain receives a greater supply of blood, oxygen and nutrients that boost its health as well as a growth hormone that helps the formation of new neurons and connections. In this analysis of previous studies, researchers from the University of Canberra looked at the effects of at least four weeks of structured physical exercise on the brain function of adults. In a variety of brain tests, they found evidence of aerobic exercise improving cognitive abilities, such as thinking, reading, learning and reasoning, while muscle training - for example, using weights - had a significant effect on memory and the brain's ability to plan and organise, the so-called executive functions. Joe Northey, study author and researcher from the Research Institute for Sport and Exercise at Canberra, said the findings were convincing enough to enable both types of exercise to be prescribed to improve brain health in the over-50s. © 2017 BBC.
Link ID: 23532 - Posted: 04.25.2017
By Lauren Gravitz, Connor was diagnosed with autism early — when he was just 18 months old. His condition was already obvious by then. “He was lining things up, switching lights on and off, on and off,” says his mother, Melissa. He was bright, but he didn’t speak much until age 3, and he was easily frustrated. Once he started school, he couldn’t sit still in class, called out answers without raising his hand and got visibly upset when he couldn’t master a math concept or a handwriting task quickly enough. “One time, he rolled himself up into the carpet like a burrito and wouldn’t come out until I got there,” Melissa recalls. (All families in this story are identified by first name only, to protect their privacy.) Connor was prescribed his first psychiatric drug, methylphenidate (Ritalin), at age 6. That didn’t last long, but when he was 7, his parents tried again. A psychiatrist suggested a low dose of amphetamine and dextroamphetamine (Adderall), a stimulant commonly used to treat attention deficit hyperactivity disorder (ADHD). The drug seemed to improve his time at school: He was able to sit still for longer periods of time and focus on what his teachers were saying. His chicken-scratch handwriting became legible. Then, it became neat. Then perfect. And then it became something Connor began to obsess over. “We were told that these are the gives and takes; if it’s helping him enough to get through school, you have to decide if it’s worth it,” Melissa says. It was worth it — for a while. © 2017 Scientific American
Link ID: 23531 - Posted: 04.25.2017
By Clare Wilson Could fasting boost your brainpower? A stomach hormone that stimulates appetite seems to promote the growth of new brain cells and protect them from the effects of ageing – and may explain why some people say that fasting makes them feel mentally sharper. When ghrelin was first discovered, it became known as the hunger hormone. It is made by the stomach when it gets empty, and whenever we go a few hours without food its levels rise in our blood. But there is also evidence that ghrelin can enhance cognition. Animals that have reduced-calorie diets have better mental abilities, and ghrelin might be part of the reason why. Injecting the hormone into mice improves their performance in learning and memory tests, and seems to boost the number of neuron connections in their brains. Now Jeffrey Davies at Swansea University, UK, and his team have found further evidence that ghrelin can stimulate brain cells to divide and multiply, a process called neurogenesis. When they added the hormone to mouse brain cells grown in a dish, it switched on a gene known to trigger neurogenesis, called fibroblast growth factor. If the same effect happens in animals, this could be how ghrelin exerts its effects on memory, says Davies, whose work was presented at the British Neuroscience Association conference this month. © Copyright Reed Business Information Ltd.