Chapter 13. Memory, Learning, and Development

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Laura Sanders Soon after systems biologist Juergen Hahn published a paper describing a way to predict whether a child has autism from a blood sample, the notes from parents began arriving. “I have a bunch of parents writing me now who want to test their kids,” says Hahn, of Rensselaer Polytechnic Institute in Troy, N.Y. “I can’t do that.” That’s because despite their promise, his group’s results, reported March 16 in PLOS Computational Biology, are preliminary — nowhere close to a debut in a clinical setting. The test will need to be confirmed and repeated in different children before it can be used to help diagnose autism. Still, the work of Hahn and colleagues, along with other recent papers, illustrates how the hunt for a concrete biological signature of autism, a biomarker, is gaining speed. Currently, pediatricians, child psychologists and therapists rely on behavioral observations and questionnaires, measures with limitations. Barring genetic tests for a handful of rare mutations, there are no blood draws, brain scans or other biological tests that can reveal whether a child has — or will get — autism. Objective tests would be incredibly useful, helping provide an early diagnosis that could lead to therapy in the first year of life, when the brain is the most malleable. A reliable biomarker might also help distinguish various types of autism, divisions that could reveal who would benefit from certain therapies. And some biomarkers may reveal a deeper understanding of how the brain normally develops. |© Society for Science & the Public 2000 - 2017

Keyword: Autism; Brain imaging
Link ID: 23479 - Posted: 04.11.2017

By Jef Akst | Previous research has shown that high doses of broad-spectrum antibiotics can affect the behavior of adult animals, and numerous epidemiological studies have begun to link early-life antibiotic use to diverse ailments in humans. A study published last week (April 4) in Nature Communications adds to this growing literature, demonstrating that even low, clinically relevant doses of the classic narrow-spectrum antibiotic penicillin can trigger changes in the gut microbiome, in the blood-brain barrier and brain chemistry, and in the behaviors of mice exposed at a young age. Treating the mice with Lactobacillus rhamnosus bacteria, however, helped protect the mice against the effects of early-life, low-dose penicillin exposure. “There are almost no babies in North America that haven’t received a course of antibiotics in their first year of life,” McMaster University coauthor John Bienenstock, who is also the director of the Brain-Body Institute at St. Joseph’s Healthcare Hamilton, said in a press release. “In this paper, we report that low-dose penicillin taken late in pregnancy and in early life of mice offspring, changes behavior and the balance of microbes in the gut. While these studies have been performed in mice, they point to popular increasing concerns about the long-term effects of antibiotics. Furthermore, our results suggest that a probiotic might be effective in preventing the detrimental effects of the penicillin.” Bienenstock and colleagues gave pregnant female mice low doses of penicillin during their last week of gestation, and continued to treat their pups until they weaned a few weeks after birth. At six weeks old, mice exposed to the antibiotic were less social, slightly less anxious, and more aggressive than unexposed mice, the team reported. In the animals’ brains, the researchers found evidence of a thinned blood-brain barrier, as well as increased production of cytokines and heightened activity of a gene that has been linked to aggressive behavior. © 1986-2017 The Scientist

Keyword: Development of the Brain; Aggression
Link ID: 23474 - Posted: 04.11.2017

Nicola Davis Sitting in a padded car seat, a small black and white bullseye stuck to his cheek, four-month-old Teo Bosten-Lam gazes at a computer. The screen is a mottled grey, like the snow on a old-fashioned television, but in the top right-hand corner is a deep blue circle. Teo has spotted it. He glances at the circle and, as he does so, it morphs into a smiley face and a triumphant jingle fills the darkened room. Buoyed by the reaction, he looks around. Suddenly a black and white spinning disc appears on the screen, issuing a sound that can only be described as “boing”. “Babies can’t resist the black and white swirl things,” says researcher Alice Skelton. “When they look away we play it and it brings them back to the screen.” A PhD student in the baby lab at the University of Sussex, Skelton is attempting to unpick a conundrum that has fascinated parents and scientists alike: when it comes to colour, exactly what can babies can see? It’s a mission that takes technology: Teo’s ability to pick up on colour is being probed with an eye-tracking system. The sticker on his cheek directs the camera to his face, while his corneal reflections and the position of his pupils are automatically detected. “What we are looking to see is, do you have to have a more saturated blue for a baby to see it than you would for a red, for example,” says Skelton. If Teo can see a colour, the novelty will attract his attention, triggering the smiley face and jingle. And this isn’t the only ingenious idea. At the first sound that indicates our participant is becoming fed up with this science lark, the screen flashes to a clip from the 1980s cartoon Dogtanian. Teo, once again, is transfixed.

Keyword: Development of the Brain; Vision
Link ID: 23473 - Posted: 04.11.2017

Ed Yong 12:00 PM ET Science Octopuses have three hearts, parrot-like beaks, venomous bites, and eight semi-autonomous arms that can taste the world. They squirt ink, contort through the tiniest of spaces, and melt into the world by changing both color and texture. They are incredibly intelligent, capable of wielding tools, solving problems, and sabotaging equipment. As Sy Montgomery once wrote, “no sci-fi alien is so startlingly strange” as an octopus. But their disarming otherness doesn’t end with their bodies. Their genes are also really weird. A team of scientists led by Joshua Rosenthal at the Marine Biological Laboratory and Eli Eisenberg at Tel Aviv University have shown that octopuses and their relatives—the cephalopods—practice a type of genetic alteration called RNA editing that’s very rare in the rest of the animal kingdom. They use it to fine-tune the information encoded by their genes without altering the genes themselves. And they do so extensively, to a far greater degree than any other animal group. “They presented this work at a recent conference, and it was a big surprise to everyone,” says Kazuka Nishikura from the Wistar Institute. “I study RNA editing in mice and humans, where it’s very restricted. The situation is very different here. I wonder if it has to do with their extremely developed brains.” It certainly seems that way. Rosenthal and Eisenberg found that RNA editing is especially rife in the neurons of cephalopods. They use it to re-code genes that are important for their nervous systems—the genes that, as Rosenthal says, “make a nerve cell a nerve cell.” And only the intelligent coleoid cephalopods—octopuses, squid, and cuttlefish—do so. The relatively dumber nautiluses do not. “Humans don’t have this. Monkeys don’t. Nothing has this except the coleoids,” says Rosenthal.

Keyword: Learning & Memory; Genes & Behavior
Link ID: 23463 - Posted: 04.07.2017

By JENNIFER MALIA In “Meet Julia,” an episode of “Sesame Street” that will air April 10 on PBS and HBO, Elmo and Abby Cadabby introduce Big Bird to Julia, a new muppet character with autism. Big Bird says, “Hi, Julia, I’m Big Bird. Nice to meet you.” But Julia continues painting without making eye contact or responding to Big Bird. On “60 Minutes,” Big Bird tells Lesley Stahl, who was on the set when “Sesame Street” was filming the new Muppet’s debut, that he thought Julia didn’t like him at first. Elmo then explains, “Julia has autism so sometimes it takes her a little longer to do things.” I can relate. When my daughter started preschool, she would run laps around the perimeter of the fenced-in playground without responding to kids who said “hi” as she passed by. One day, she stopped in her tracks to pick up a jacket that had fallen to the ground, handed it to a girl without saying a word, and continued running. The kids on the playground probably assumed she didn’t like them — just as Big Bird did. Within the past year, my daughter, who is now 3, my 2-year-old son and I were all given diagnoses of autism spectrum disorder because of our repetitive behaviors, obsessive interests, sensory issues and difficulty with social interactions and pragmatic communication skills. My kids are on the mild to moderate part of the spectrum, having language, but not intellectual, impairments. (I also have a 4-year-old daughter who does not have a diagnosis.) Julia gives me hope that my children and their peers will grow up in a world where autism is normalized, rather than stigmatized. Preschoolers are the primary audience for “Sesame Street,” an educational television program where young children watching Julia’s interactions with her peers can learn by example to support autism acceptance. Since one in 68 American children have an autism diagnosis, wider understanding of the condition is valuable for them as well as for their peers. © 2017 The New York Times Company

Keyword: Autism
Link ID: 23462 - Posted: 04.07.2017

By Tracy Vence Last year, 5 percent of the babies born to nearly 1,000 mothers in the U.S. who showed signs of Zika virus infection during their pregnancies had birth defects, the US Centers for Disease Control and Prevention (CDC) reported this week (April 3). Among babies born to the 250 US mothers with confirmed Zika infection during their pregnancies, just shy of 10 percent had birth defects. The agency’s latest analysis is based on data from the US Zika Pregnancy Registry, which does not include information from Puerto Rico (where CDC has a separate database). During a press briefing, CDC Acting Director Anne Schuchat told reporters that researchers and clinicians have observed a variety of brain-related birth defects in babies with congenital Zika infection, beyond microcephaly. “Some seemingly healthy babies . . . may have developmental problems that become evident months after birth,” she said. “Although we’re still learning about the full range of birth defects that can occur when a women is infected with Zika during pregnancy, we’ve seen that it can cause brain abnormalities, vision problems, hearing problems, and other consequences of brain damage that might require lifelong specialized care.” Schuchat described cases of congenital Zika infection in which babies experienced seizures, reduced motor control, feeding difficulties, missed developmental milestones (like sitting up), or inconsolable crying. “These circumstances are just heartbreaking,” she said. © 1986-2017 The Scientist

Keyword: Development of the Brain
Link ID: 23461 - Posted: 04.07.2017

By James Gallagher Health and science reporter, What really happens when we make and store memories has been unravelled in a discovery that surprised even the scientists who made it. The US and Japanese team found that the brain "doubles up" by simultaneously making two memories of events. One is for the here-and-now and the other for a lifetime, they found. It had been thought that all memories start as a short-term memory and are then slowly converted into a long-term one. Experts said the findings were surprising, but also beautiful and convincing. 'Significant advance' Two parts of the brain are heavily involved in remembering our personal experiences. The hippocampus is the place for short-term memories while the cortex is home to long-term memories. This idea became famous after the case of Henry Molaison in the 1950s. His hippocampus was damaged during epilepsy surgery and he was no longer able to make new memories, but his ones from before the operation were still there. So the prevailing idea was that memories are formed in the hippocampus and then moved to the cortex where they are "banked". The team at the Riken-MIT Center for Neural Circuit Genetics have done something mind-bogglingly advanced to show this is not the case. The experiments had to be performed on mice, but are thought to apply to human brains too. They involved watching specific memories form as a cluster of connected brain cells in reaction to a shock. Researchers then used light beamed into the brain to control the activity of individual neurons - they could literally switch memories on or off. The results, published in the journal Science, showed that memories were formed simultaneously in the hippocampus and the cortex. Prof Susumu Tonegawa, the director of the research centre, said: "This was surprising." He told the BBC News website: "This is contrary to the popular hypothesis that has been held for decades. Copyright © 2017

Keyword: Learning & Memory
Link ID: 23460 - Posted: 04.07.2017

by Laura Sanders The way babies learn to speak is nothing short of breathtaking. Their brains are learning the differences between sounds, rehearsing mouth movements and mastering vocabulary by putting words into meaningful context. It’s a lot to fit in between naps and diaper changes. A recent study shows just how durable this early language learning is. Dutch-speaking adults who were adopted from South Korea as preverbal babies held on to latent Korean language skills, researchers report online January 18 in Royal Society Open Science. In the first months of their lives, these people had already laid down the foundation for speaking Korean — a foundation that persisted for decades undetected, only revealing itself later in careful laboratory tests. Researchers tested how well people could learn to identify and speak tricky Korean sounds. “For Korean listeners, these sounds are easy to distinguish, but for second-language learners they are very difficult to master,” says study coauthor Mirjam Broersma, a psycholinguist of Radboud University in Nijmegen, Netherlands. For instance, a native Dutch speaker would listen to three distinct Korean sounds and hear only the same “t” sound. Broersma and her colleagues compared the language-absorbing skills of a group of 29 native Dutch speakers to 29 South Korea-born Dutch speakers. Half of the adoptees moved to the Netherlands when they were older than 17 months — ages at which the kids had probably begun talking. The other half were adopted as preverbal babies younger than 6 months. As a group, the South Korea-born adults outperformed the native-born Dutch adults, more easily learning both to recognize and speak the Korean sounds. |© Society for Science & the Public 2000 - 2017

Keyword: Language; Development of the Brain
Link ID: 23455 - Posted: 04.06.2017

By Matt Reynolds Google’s latest take on machine translation could make it easier for people to communicate with those speaking a different language, by translating speech directly into text in a language they understand. Machine translation of speech normally works by first converting it into text, then translating that into text in another language. But any error in speech recognition will lead to an error in transcription and a mistake in the translation. Researchers at Google Brain, the tech giant’s deep learning research arm, have turned to neural networks to cut out the middle step. By skipping transcription, the approach could potentially allow for more accurate and quicker translations. The team trained its system on hundreds of hours of Spanish audio with corresponding English text. In each case, it used several layers of neural networks – computer systems loosely modelled on the human brain – to match sections of the spoken Spanish with the written translation. To do this, it analysed the waveform of the Spanish audio to learn which parts seemed to correspond with which chunks of written English. When it was then asked to translate, each neural layer used this knowledge to manipulate the audio waveform until it was turned into the corresponding section of written English. “It learns to find patterns of correspondence between the waveforms in the source language and the written text,” says Dzmitry Bahdanau at the University of Montreal in Canada, who wasn’t involved with the work. © Copyright Reed Business Information Ltd.

Keyword: Language; Robotics
Link ID: 23450 - Posted: 04.05.2017

Bruce Bower Kids can have virtual out-of-body experiences as early as age 6. Oddly enough, the ability to inhabit a virtual avatar signals a budding sense that one’s self is located in one’s own body, researchers say. Grade-schoolers were stroked on their backs with a stick while viewing virtual versions of themselves undergoing the same touch. Just after the session ended, the children often reported that they had felt like the virtual body was their actual body, says psychologist Dorothy Cowie of Durham University in England. This sense of being a self in a body, which can be virtually manipulated via sight and touch, gets stronger and more nuanced throughout childhood, the scientists report March 22 in Developmental Science. By around age 10, individuals start to report feeling the touch of a stick stroking a virtual body, denoting a growing integration of sensations with the experience of body ownership, Cowie’s team finds. A year after that, youngsters still don’t display all the elements of identifying self with body observed in adults. During virtual reality trials, only adults perceived their actual bodies as physically moving through space toward virtual bodies receiving synchronized touches. This first-of-its-kind study opens the way to studying how a sense of self develops from childhood on, says cognitive neuroscientist Olaf Blanke of the Swiss Federal Institute of Technology in Lausanne. “The new data clearly show that kids at age 6 have brain mechanisms that generate an experience of being a self located inside one’s own body.” He suspects that a beginner’s version of “my body is me” emerges by age 4. |© Society for Science & the Public 2000 - 2017.

Keyword: Consciousness; Development of the Brain
Link ID: 23446 - Posted: 04.04.2017

by Emilie Reas Alzheimer’s disease (AD) has been characterized as a “complete loss of self.” Early on when memory begins to fade, the victim has difficulty recalling names, their grocery list or where they put their keys. As the disease progresses, they have trouble staying focused, planning and performing basic daily activities. From the exterior, dementia appears to ravage one’s intellect and personality; yet as mere observers, it’s impossible to ascertain how consciousness of the self and environment is transformed by dementia. The celebrated late neurologist Oliver Sacks once suggested that, “Style, neurologically, is the deepest part of one’s being and may be preserved, almost to the last, in dementia.” Is this remaining neurological “style” sufficient to preserve consciousness? Is the AD patient aware of their deteriorating cognition, retaining a sense of identity or morality, or can they still connect with friends and loved ones? Emerging advances in neuroscience have enabled researchers to more precisely probe the AD brain, suggesting that although some aspects of consciousness are compromised by dementia, others are remarkably spared. Scientists are beginning to piece together how the selective loss of some functions, but the preservation of others, alters consciousness in AD. A recent study found that the severity of cognitive impairment strongly relates to “meta-cognition” (reflecting on one’s own condition), moral judgments and thinking about the future, whereas basic personal identity and body awareness remain. Perhaps the most widely observed deficit in consciousness is “anosognosia,” impaired awareness of one’s own illness; whereas individuals with mild cognitive impairment (MCI; considered a precursor to full AD) are aware of their declining memory, AD patients may be unaware of their impairments. These behavioral signs suggest that only some aspects of consciousness and self-awareness are truly lost in AD.

Keyword: Alzheimers; Consciousness
Link ID: 23444 - Posted: 04.04.2017

By CHRISTOPHER MELE You were sure you left the keys right there on the counter, and now they are nowhere to be found. Where could they be? Misplacing objects is an everyday occurrence, but finding them can be like going on a treasure hunt without a map. Here are some recommendations from experts to help you recover what is lost. (Consider printing this out and putting it someplace you can easily find it.) Stay calm and search on One of the biggest mistakes people make is becoming panicked or angry, which leads to frantic, unfocused searching, said Michael Solomon, who wrote the book “How to Find Lost Objects.” One of the axioms of his book is: “There are no missing objects. Only unsystematic searchers.” Look for the item where it’s supposed to be. Sometimes objects undergo “domestic drift” in which they were left wherever they were last used, Mr. Solomon said. “Objects are apt to wander,” he wrote in his book. “I have found, though, that they tend to travel no more than 18 inches from their original location.” Be disciplined in your search A common trap is forgetting where you have already searched, Corbin A. Cunningham, a Ph.D. student at the Department of Psychological and Brain Sciences at Johns Hopkins University, said in an email. “Go from one room to another, and only move on if you think you have searched everywhere in that room,” he wrote. Once you have thoroughly searched an area and ruled it out, don’t waste time returning to it. © 2017 The New York Times Company

Keyword: Learning & Memory
Link ID: 23440 - Posted: 04.03.2017

By Eric Boodman, MEDFORD, Mass. — They look like little more than grayish-black grains of couscous floating in water. But they are actually African clawed frogs-to-be, replete with minuscule blobs that will become eyes. “These little beans here are what I do the surgery on,” said Douglas Blackiston, a postdoctoral fellow at Tufts University’s Allen Discovery Center, holding out a Petri dish. On Thursday, Blackiston published the results of a few years’ worth of those microscopic surgeries, and the finding is bizarre: If you transplant an eye onto what will become the tadpole’s tail, that organ — misplaced though it may be — can allow the animal to see. Admittedly, it’s impossible for humans to look through a clawed frog’s eyes, and in this case, Blackiston and the director of his lab, Michael Levin, were mainly testing whether the tadpoles could perceive movement and colored light. But they say their research doesn’t just have implications for scientists’ ability to restore vision; it also sheds light on how to connect implants and grafts to the body’s own wiring. “You implant these organs, but you want them to be functionally integrated with the host nervous system otherwise they aren’t going to work,” said Levin, the lead author of a paper published Thursday in Nature Regenerative Medicine. Do you have to “connect up every neuron,” he wondered, or can you make use of the natural ability of the nervous system to adapt and rewire itself? © 2017 Scientific American

Keyword: Development of the Brain; Vision
Link ID: 23433 - Posted: 03.31.2017

Elle Hunt Inches above the seafloor of Sydney’s Cabbage Tree Bay, with the proximity made possible by several millimetres of neoprene and a scuba diving tank, I’m just about eyeball to eyeball with this creature: an Australian giant cuttlefish. Even allowing for the magnifying effects of the mask snug across my nose, it must be about 60cm (two feet) long, and the peculiarities that abound in the cephalopod family, that includes octopuses and squid, are the more striking writ so large. ADVERTISING Its body – shaped around an internal surfboard-like shell, tailing off into a fistful of tentacles – has the shifting colour of velvet in light, and its W-shaped pupils lend it a stern expression. I don’t think I’m imagining some recognition on its part. The question is, of what? It was an encounter like this one – “at exactly the same place, actually, to the foot” – that first prompted Peter Godfrey-Smith to think about these most other of minds. An Australian academic philosopher, he’d recently been appointed a professor at Harvard. While snorkelling on a visit home to Sydney in about 2007, he came across a giant cuttlefish. The experience had a profound effect on him, establishing an unlikely framework for his own study of philosophy, first at Harvard and then the City University of New York. The cuttlefish hadn’t been afraid – it had seemed as curious about him as he was about it. But to imagine cephalopods’ experience of the world as some iteration of our own may sell them short, given the many millions of years of separation between us – nearly twice as many as with humans and any other vertebrate (mammal, bird or fish)

Keyword: Evolution; Learning & Memory
Link ID: 23429 - Posted: 03.30.2017

By ALICE CALLAHAN Peruse the infant formula aisle, or check out the options for prenatal nutritional supplements, and you’ll find that nearly all these products boast a “brain nourishing” omega-3 fatty acid called DHA. But despite decades of research, it’s still not clear that DHA in formula boosts brain health in babies, or that mothers need to go out of their way to take DHA supplements. A systematic review of studies published this month by the Cochrane Collaboration concluded there was no clear evidence that formula supplementation with DHA, or docosahexaenoic acid, a nutrient found mainly in fish and fish oil, improves infant brain development. At the same time, it found no harm from adding the nutrient. The findings are consistent with a review of the effects of omega-3 supplements in pregnancy and infancy published by the Agency for Healthcare Research and Quality last fall that found little evidence of benefit. Still, many experts believe there is value in including DHA in formula. “Even if you can’t easily prove it, because it’s hard to prove developmental outcomes, it makes sense to use it,” said Dr. Steven Abrams, a professor of pediatrics at Dell Medical School at the University of Texas at Austin. “It’s probably a good idea to keep it in there, and it’s certainly safe.” During pregnancy and the first few years of life, DHA accumulates in the brain and retina of the eye and plays an important role in neural and vision development. Breast milk contains DHA in varying concentrations, depending on how much is in the mother’s diet, and some DHA can be made in the body from precursor omega-3 fatty acids, although this process is inefficient. © 2017 The New York Times Company

Keyword: Development of the Brain
Link ID: 23428 - Posted: 03.30.2017

Rae Ellen Bichell Exposure to lead as a child can affect an adult decades later, according to a study out Tuesday that suggests a link between early childhood lead exposure and a dip in a person's later cognitive ability and socioeconomic status. Lead in the United States can come from lots of sources: old, peeling paint; contaminated soil; or water that's passed through lead pipes. Before policies were enacted to get rid of lead in gasoline, it could even come from particles in the fumes that leave car tailpipes. "It's toxic to many parts of the body, but in particular in can accumulate in the bloodstream and pass through the blood brain barrier to reach the brain," says the study's first author, Aaron Reuben, a graduate student in clinical psychology at Duke University. Reuben and his colleagues published the results of a long-term study on the lingering effects of lead. Researchers had kept in touch with about 560 people for decades — starting when they were born in Dunedin, New Zealand, in the 1970s, all the way up to the present. As children, the study participants were tested on their cognitive abilities; researchers determined IQ scores based on tests of working memory, pattern recognition, verbal comprehension and ability to solve problems, among other skills. When the kids were 11 years old, researchers tested their blood for lead. (That measurement is thought to be a rough indicator of lead exposure in the few months before the blood draw.) Then, when they turned 38 years old, the cognitive ability of these study participants was tested again. As Reuben and his colleagues write in this week's issue of JAMA, the journal of the American Medical Association, they found a subtle but worrisome pattern in the data. © 2017 npr

Keyword: Development of the Brain; Neurotoxins
Link ID: 23422 - Posted: 03.29.2017

By C. CLAIBORNE RAY Q. When four of us shared memories of our very young lives, not one of us could recall events before the age of 4 or possibly 3. Is this common? A. Yes. For adults, remembering events only after age 3½ or 4 is typical, studies have found. The phenomenon was named childhood amnesia by Freud and identified late in the 19th century by the pioneering French researcher Victor Henri and his wife, Catherine. The Henris published a questionnaire on early memories in 1895, and the results from 123 people were published in 1897. Most of the participants’ earliest memories came from when they were 2 to 4 years old; the average was age 3. Very few participants recalled events from the first year of life. Many subsequent studies found similar results. Several theories have been offered to explain the timing of laying down permanent memories. One widely studied idea relates the formation of children’s earliest memories to when they start talking about past events with their mothers, suggesting a link between memories and the age of language acquisition. More recent studies, in 2010 and 2014, found discrepancies in the accuracy of young children’s estimates of when things had occurred in their lives. Another 2014 study found a progressive loss of recall as a child ages, with 5-, 6- and 7-year-olds remembering 60 percent or more of some early-life events that were discussed at age 3, while 8- and 9-year-olds remembered only 40 percent of these events. © 2017 The New York Times Company

Keyword: Learning & Memory; Development of the Brain
Link ID: 23412 - Posted: 03.28.2017

By Linda Searing The precise cause, or causes, of dementias such as Alzheimer’s disease remain unclear, but one theory points to molecules called free radicals that can damage nerve cells. This damage, called oxidative stress, may lead to changes in the brain over time that result in dementia. Might antioxidant supplements prevent this? The study involved 7,540 men 60 and older (average age, 67) with no indications of dementia and no history of serious head injury, substance abuse or neurological conditions that affect cognition. They were randomly assigned to take vitamin E (an antioxidant, 400 International Units daily), selenium (also an antioxidant, 200 micrograms daily), both vitamin E and selenium or a placebo. The men also had their memory assessed periodically. In just over five years, 325 of the men (about 4 percent) developed dementia, with essentially no difference in the rate of occurrence between those who took one or both supplements and those who took the placebo. The researchers concluded that the antioxidant supplements “did not forestall dementia and are not recommended as preventive agents.” Who may be affected? Older men. The risk for dementia increases with advanced age and is most common among the very elderly. Memory loss is the most well-known symptom, but people with dementia may also have problems thinking, speaking, controlling emotions and doing daily activities such as getting dressed and eating. Alzheimer’s disease is the most common type of dementia, affecting more than 5.5 million Americans, including more than 10 percent of those 65 and older and more women than men. Caveats Participants took the supplements for a relatively short time. Whether the findings would apply to women was not tested. The study did not prove that the dementia developed by the study participants was caused by oxidative stress. © 1996-2017 The Washington Post

Keyword: Alzheimers
Link ID: 23403 - Posted: 03.25.2017

By Jason G. Goldman In the summer of 2015 University of Oxford zoologists Antone Martinho III and Alex Kacelnik began quite the cute experiment—one involving ducklings and blindfolds. They wanted to see how the baby birds imprinted on their mothers depending on which eye was available. Why? Because birds lack a part of the brain humans take for granted. Suspended between the left and right hemispheres of our brains sits the corpus callosum, a thick bundle of nerves. It acts as an information bridge, allowing the left and right sides to rapidly communicate and act as a coherent whole. Although the hemispheres of a bird's brain are not entirely separated, the animals do not enjoy the benefits of this pathway. This quirk of avian neuroanatomy sets up a natural experiment. “I was in St. James's Park in London, and I saw some ducklings with their parents in the lake,” Martinho says. “It occurred to me that we could look at the instantaneous transfer of information through imprinting.” The researchers covered one eye of each of 64 ducklings and then presented a fake red or blue adult duck. This colored duck became “Mom,” and the ducklings followed it around. But when some of the ducklings' blindfolds were swapped so they could see out of only the other eye, they did not seem to recognize their “parent” anymore. Instead the ducklings in this situation showed equal affinity for both the red and blue ducks. It took three hours before any preferences began to emerge. Meanwhile ducklings with eyes that were each imprinted to a different duck did not show any parental preferences when allowed to use both eyes at once. The study was recently published in the journal Animal Behaviour. © 2017 Scientific American

Keyword: Learning & Memory; Vision
Link ID: 23401 - Posted: 03.24.2017

by Laura Sanders Many babies born early spend extra time in the hospital, receiving the care of dedicated teams of doctors and nurses. For these babies, the hospital is their first home. And early experiences there, from lights to sounds to touches, may influence how babies develop. Touches early in life in the NICU, both pleasant and not, may shape how a baby’s brain responds to gentle touches later, a new study suggests. The results, published online March 16 in Current Biology, draw attention to the importance of touch, both in type and number. Young babies can’t see that well. But the sense of touch develops early, making it a prime way to get messages to fuzzy-eyed, pre-verbal babies. “We focused on touch because it really is some of the basis for communication between parents and child,” says study coauthor Nathalie Maitre, a neonatologist and neuroscientist at Nationwide Children’s Hospital in Columbus, Ohio. Maitre and her colleagues studied how babies’ brains responded to a light puff of air on the palms of their hands — a “very gentle and very weak touch,” she says. They measured these responses by putting adorable, tiny electroencephalogram, or EEG, caps on the babies. The researchers puffed babies’ hands shortly before they were sent home. Sixty-one of the babies were born early, from 24 to 36 weeks gestation. At the time of the puff experiment, they had already spent a median of 28 days in the hospital. Another group of 55 babies, born full-term, was tested in the three days after birth. |© Society for Science & the Public 2000 - 2017

Keyword: Pain & Touch; Development of the Brain
Link ID: 23398 - Posted: 03.23.2017