Chapter 7. Life-Span Development of the Brain and Behavior
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by Laura Sanders On a test of visual perception, children with autism perceive moving dots with more clarity than children without the disorder. The results, published in the May 6 Journal of Neuroscience, reveal a way in which children with autism see the world differently. When asked to determine the overall direction of a mess of dots moving in slightly different directions, children with autism outperformed children without the disorder. Other tests of motion detection didn’t turn up any differences. The results suggest that children with autism may be taking in and combining more motion information than children without autism, says study coauthor Catherine Manning of the University of Oxford. This heightened ability may contribute to feelings of sensory overload, the researchers suggest. © Society for Science & the Public 2000 - 2015
Ian Sample, science editor Brain scans of children who were born prematurely have revealed differences in the connectivity of key regions that may play a role in developmental disorders. Previous studies have already highlighted that children who are born preterm are more at risk of autism and other behavioural conditions, such as the poor attention that is associated with ADHD, or attention deficit hyperactivity disorder. The new findings could help doctors understand why preterm children are so often affected, and work out whether medications or different styles of care could help the children reach their full potential. Researchers at King’s College London scanned the brains of 66 infants on average 42 weeks after their mothers’ last period before the birth. Forty seven of the babies were born prematurely, at less than 33 weeks. The other 19 babies were born on average after 40 weeks gestation. In their final weeks in the womb, babies’ brains are building connections at an incredible rate, which makes them particularly sensitive to changes in the last trimester. If a baby is born prematurely, the crucial period of brain growth happens in the radically different environment of the neonatal unit. From the MRI scans, the scientists found that infants born prematurely had increased connectivity in only one part of the brain they tested. A region called the thalamus, a kind of neural relay station, was better connected to a part called the lateral sensory cortex, which handles signals from the mouth, lips and jaw. The result might be explained by pre-term babies breast or bottle feeding much earlier, or being given dummies while on supportive breathing machines. © 2015 Guardian News and Media Limited
James Gorman If modern science is right, the great mystery of embryonic development is less about how life unfolds, and more about how it folds. Embryos of many organisms grow from two cells to four, then eight, and so on until there are thousands in a kind of ball. Then sheets of cells start to make folds or furrows as the basic shape of the creature — fly or fish or human — begins to emerge. One of the most striking examples is a moment in the development of Volvox, a kind of algae that forms one of the simplest multicellular organisms. When it is a sphere of a few thousand cells, it reaches adult size, but not adult shape. So it turns itself inside out. Scientists at the University of Cambridge in England have made a time-lapse recording of the process that shows it in three dimensions for the first time and has enough detail that researchers can check their mathematical descriptions of the transformation. © 2015 The New York Times Company
Keyword: Development of the Brain
Link ID: 20888 - Posted: 05.05.2015
Roger Dobson Tapping your fingers on the table is usually a sign of boredom or irritation. But not all tappers are equal, it seems. Men drum their digits slightly faster than women and people in their twenties tap substantially faster than people twice their age. The results of the first study into finger-tapping speeds also found that smokers tap a little faster than non-smokers and fit people tap faster than those who avoid exercise. The research, carried out by scientists at two universities in Istanbul – Bogazici University and Fatih University – examined the tapping rates and “finger load capacities” of 148 people aged between 18 and 85. Each participant was asked to perform a one-minute tapping exercise on a keyboard at “maximum volitional tempo”. Researchers found that the index finger on the right hand of both men and women was the fastest digit, achieving a tapping rate of up to five beats a second among those in their twenties. The middle finger was almost as nifty as the index finger, but the little finger – the slowest digit in the bunch – was capable only of a sluggish 3.8 taps a second among people in the same age group. At first glance, the study might appear to be rather frivolous. But a deeper understanding of finger tapping could aid the design of computer keyboards and musical instruments. It may also aid researchers who use finger-tapping tests for medical assessment of neurological conditions such as Parkinson’s disease, schizophrenia and Alzheimer’s.
By Aleksandra Sagan, CBC News In a Dutch town about 20 kilometres outside of Amsterdam, a small community lives in what at first glance seems like a real-life version of The Truman Show. Hogewey has a grocery store, a theatre and a barber shop. The only twist is that many of its 152 residents live unaware that their orderly community is actually a nursing home for people with severe dementia. "We protect our residents from the unsafe world. They do not understand the world outside this because the outside world doesn't understand them," says Yvonne van Amerongen, an employee at Hogewey who also helped develop the concept. Hogewey was officially opened in 2007, but the idea has now caught the attention of health-care professionals in Ontario and Alberta. Rhonda Desroches, who helped create a smaller-scale Hogewey in Penetanguishene, Ont., says relatives of the residents are pleased with how happy their family members seem to be in the new facility. Dementia is a growing problem. According to the Alzheimer Society Canada, one out of 20 Canadians over 65 has Alzheimer's Disease, and that figure jumps to one in four for Canadians over 85. In 2012, the World Health Organization declared dementia a public health priority. Many dementia patients move into nursing homes, where they are monitored in a safe setting. But some medical professionals want to shift patients away from unfamiliar, clinical settings and into spaces that resemble more typical surroundings. Hogewey creates a familiar, "normal" environment that dementia patients understand, says van Amerongen. The citizens of Hogewey share a house with about six others, and are classified according to one of seven lifestyles. ©2015 CBC/Radio-Canada
Link ID: 20875 - Posted: 05.04.2015
Children who were often bullied by their peers may experience more anxiety and depression than children who were abused by adults, a finding that U.S. and British researchers say highlights an "imbalance" in school services to tackle bullying. Researchers followed the mental health of more than 4,000 children in Avon, south west England from birth to age 18 and 1,400 others in North Carolina from age nine up to age 26 through parent questionnaires and clinical interviews. In the Avon study, maltreatment was defined as physical, emotional, or sexual abuse or "maladaptive parenting" such as hitting, shouting and hostility. Children were interviewed about the frequency of bullying, which included overt threats, physical violence and nasty names as well as social exclusion or spreading lies or rumours. The results consistently showed an increased risk of anxiety, depression, self-harm and suicidal tendencies in children who were bullied, whether or not they had a history of abuse by adults, Prof. William Copeland, a clinical psychologist at Duke University School of Medicine in Durham, N.C. and his co-authors concluded in Tuesday's issue of Lancet Psychiatry. "What was a surprise was to see [the results] were as significant and pervasive as what we see for children that are physically abused, sexually abused or neglected," Copeland said. Government policies have focused almost exclusively on providing services for child abuse but much less attention and resources are devoted to bullying, the researchers said. Copeland's previous research showed long-term repercussions from bullying persist — and that includes impacts on physical health, dropping out of school and trouble with authorities. ©2015 CBC/Radio-Canada
By Tina Hesman Saey People with depression have more mitochondrial DNA and shorter telomeres than nondepressed people do, an international team of researchers reports online April 23 in Current Biology. Mitochondria are organelles that produce energy for cells. Mitochondria seem to become inefficient under stress, the team found, so more mitochondria may be needed to produce enough energy. Telomeres are the DNA endcaps on chromosomes that prevent the genetic material from unraveling. Short telomeres are associated with shorter life spans. The altered DNA may reflect metabolic changes associated with depression, the researchers say. Experiments with mice showed that these DNA changes are brought on by stress or by stress hormones. Four weeks after scientists stopped stressing the mice, their mitochondrial and telomere DNA had returned to normal. Those results indicate that the molecular changes are reversible. Researchers also studied DNA from more than 11,000 people to learn whether past stress was responsible for the molecular changes seen in people with depression. Depression was associated with the DNA changes, but having a stressful life was not. For instance, people who had experienced childhood sexual abuse but were not depressed did not have statistically meaningful changes to their DNA compared with people who had no history of abuse. The findings suggest that stress can change DNA but many people can bounce back. Depressed people may have a harder time recovering from the molecular damage. © Society for Science & the Public 2000 - 2015.
Pete Etchells Over the past few years, there seems to have been a insidious pandemic of nonsense neuroscientific claims creeping into the education system. In 2013, the Wellcome Trust commissioned a series of surveys of parents and teachers, asking about various types of educational tools or teaching methods, and the extent to which they believe they have a basis in neuroscience. Worryingly, 76% of teachers responded that they used learning styles in their teaching, and a further 19% responded that they either use, or intend to use, left brain/right brain distinctions to help inform learning methods. Both of these approaches have been thoroughly debunked, and have no place in either neuroscience or education. In October last year, I reported on another study that showed that in the intervening time, things hadn’t really improved – 91% of UK teachers in that survey believed that there were differences in the way that students think and learn, depending on which hemisphere of the brain is ‘dominant’. And despite lots of great attempts to debunk myths about the brain, they still seem to persist and take up residence as ‘commonplace’ knowledge, being passed onto children as if they are fact. When I wrote about an ATL proposal to train teachers in neuroscience – a well-intended idea, but ultimately grounded in nonsense about left brain/right brain myths – I commented at the end that we need to do more to bring teachers and neuroscientists together, to discuss whether neuroscience has a relevant role in informing the way we teach students. Now, a new initiative funded by the Wellcome Trust is aiming to just that. © 2015 Guardian News and Media Limited
by Katie Collins Sarah-Jayne Blakemore is just as fascinated by the links between neuroscience and education as she is outraged by the pseudo science that often intrudes upon this territory. Neuroscience in education has really been flourishing in recent years, she says on stage at WIRED Health 2015, but some theories about neuroscience have already infiltrated schools, and not necessarily in a good way. Some products that makes claims about having a positive effect on cognition make bogus claims that may well have positive effects in the classroom, but at the same time promote completely inaccurate science. Blakemore points specifically to the Brain Gym educational model, which claims to improve memory, concentration and information retention. There are no problems with the exercises themselves, she says, but the claims made about the brain are baseless. For a start, she said, Brain Gym claims that children can push "brain buttons" on their bodies that will stimulate blood flow to the brain. Another physical exercise claimed to increase and improve connectivity between the two sides of the brain. "This makes no sense -- they are in communication anyway," says Blakemore. Teachers like Brain Gym because it does what it says and results in improvements in the classroom, but it could just as easily be placebo or novelty causing the effects. One thing Blakemore is sure of? "They're nothing to do with brain buttons or coordinating the two brain hemispheres."
Keyword: Development of the Brain
Link ID: 20844 - Posted: 04.25.2015
By Maggie Fox Another study aimed at soothing the fears of some parents shows that vaccines don't cause autism. This one takes a special look at children with older siblings diagnosed with autism, who do themselves have a higher risk of an autism spectrum disorder. But even these high-risk kids aren't more likely to develop autism if they're vaccinated, according to the report in the Journal of the American Medical Association. "We found that there was no harmful association between receipt of the MMR (measles, mumps and rubella) vaccine and development of autism spectrum disorder," said Dr. Anjali Jain of The Lewin Group, a health consulting group in Falls Church, Virginia, who led the study. Kids who had older brothers or sisters with autism were less likely to be vaccinated on time themselves, probably because their parents had vaccine worries. But those who were vaccinated were no more likely than the unvaccinated children to develop autism, Jain's team found. Autism is very common. The Centers for Disease Control and Prevention says one in 68 U.S. kids has an autism spectrum disorder. Numbers have been growing but CDC says much of this almost certainly reflects more awareness and diagnosis of kids who would have been missed in years past.
Link ID: 20829 - Posted: 04.22.2015
The brains of babies “light up” in a similar way to adults when exposed to the same painful stimulus, suggesting they feel pain much like adults do, researchers said on Tuesday. In the first of its kind study using magnetic resonance imaging (MRI), scientists from Britain’s Oxford University found that 18 of the 20 brain regions active in adults experiencing pain were also active in babies. Brain scans of the sleeping infants while they were subjected to mild pokes on the bottom of their feet with a special rod – creating a sensation “like being poked with a pencil” – also showed their brains had the same response to a slighter “poke” as adults did to a stimulus four times as strong, suggesting babies have a much lower pain threshold. “Obviously babies can’t tell us about their experience of pain and it is difficult to infer pain from visual observations,” said Rebeccah Slater, a doctor at Oxford’s paediatrics department who led the study. “In fact some people have argued that babies’ brains are not developed enough for them to really feel pain ... [yet] our study provides the first really strong evidence this is not the case.” Even as recently as the 1980s it was common practice for babies undergoing surgery to be given neuromuscular blocks but no pain relief medication. Last year, a review of neonatal pain management in intensive care found that although these babies experience an average of 11 painful procedures per day, 60% do not receive any kind of pain medication. © 2015 Guardian News and Media Limited
Mothers may influence the mood and behaviour of their babies through their breast milk, researchers say. There's growing evidence that mother's milk doesn't just affect the growth of a baby's body "but also areas of their brain that shape their motivations, their emotions, and therefore their behavioural activity," says Katie Hinde, an assistant professor of human evolutionary biology at Harvard University. In a paper published in the journal Evolution, Medicine and Public Health, Hinde and two other researchers propose a way in which the composition of breast milk could influence a baby's brain and behaviour. If food is scarce or there are a lot of predators around, it may be better for a mother to have a baby that is calmer and focuses on growing rather than one that is very active and playful, Hinde told CBC Radio's Quirks & Quarks in an interview that airs Saturday. It may be possible to influence a baby's activity level by changing the composition of the milk to affect the bacteria in the infant's gut, she added. Breast milk contains a lot of sugars that infants can't digest, but that feed bacteria that live in human intestines. Those bacteria don't just help digest food, said Hinde. "They can release chemical signals that travel to the infant's brain and shape neurodevelopment." ©2015 CBC/Radio-Canada
by Beth Mole Small doses of lead may have big impacts on reading and math scores, scientists report April 7 in Environmental Health. Researchers looked at third grade test scores and levels of lead in blood samples from 58,650 students in Chicago public schools. As little as 2 micrograms of lead per deciliter of blood was associated with lower reading and math scores. The Centers for Disease Control and Prevention recommends that anything above 5 micrograms per deciliter is of concern. The researchers estimate that childhood lead levels at or above 5 micrograms per deciliter of blood accounted for as many as 25 percent of the children in the study failing reading and math standardized tests. The findings confirm that lead exposure, even at low doses, is associated with poor school performance. © Society for Science & the Public 2000 - 2015
|By Cari Nierenberg and LiveScience Women who develop gestational diabetes early in their pregnancy have a higher chance of having a child with autism than women who don't develop the condition, a new study suggests. Researchers found that mothers-to-be who developed gestational diabetes — high blood sugar during pregnancy in women who have never had diabetes — by their 26th week of pregnancy were 63 percent more likely to have a child diagnosed with an autism spectrum disorder (ASD) compared with women who did not have gestational diabetes at any point during their pregnancy (and who also did not have type 2 diabetes prior to pregnancy). The finding does not mean that autism is common among children born to women who had gestational diabetes. "Autism is still rare," said study co-author Anny Xiang, a research scientist at Kaiser Permanente Southern California in Pasadena. The findings show that, although the risk of having a child with autism is still low among women who have gestational diabetes early in pregnancy (before 26 weeks), the study did find a relationship between these women and an increased risk that the child would have autism, Xiang said. The study, published today (April 14) in the Journal of the American Medical Association, looked at more than 320,000 children born in Southern California between 1995 and 2009. About 8 percent of the kids were born to mothers who had pregnancy-related diabetes, and 2 percent had mothers with type 2 diabetes. © 2015 Scientific American
By Neuroskeptic According to a large study just published in the Journal of Autism and Developmental Disorders, there’s no correlation between brain anatomy and self-reported autistic traits. Dutch researchers P. Cedric M. P. Koolschijn and colleagues looked at two samples of young Dutch adults: an ‘exploration’ sample of 204, and a separate ‘validation’ group of 304 individuals. Most of the participants did not have autism. The researchers looked for associations between various aspects of brain structure and autistic traits, using the AQ questionnaire, a popular self-report measure. Autistic traits are personality or behavior features similar to (but generally milder than) autism symptoms. For example, the first item on the AQ is “I prefer to do things with others rather than on my own.” If you disagree with that, you get a point. More points means more autistic traits. Koolschijn et al. used VBM, vertex-based cortical thickness analysis, and diffusion weighted imaging to explore different aspects of brain grey and white matter anatomy. However, although AQ scores were weakly correlated with the volume of a few brain areas in the exploration sample, none of these correlations were confirmed in the larger validation sample, suggesting that they were just false positives caused by the large number of multiple comparisons.
A study using mice has uncovered a possible cause of Alzheimer’s disease, and suggests that a drug currently being investigated in human clinical trials to treat cancer could prevent the illness. The research has been heralded as offering hope of finding new treatments for dementia, an illness that affects 850,000 people in the UK. The findings, by Duke University in America and published in the Journal of Neuroscience, are surprising, according to one of the authors, as they contradict current thinking on the disease. The research suggests that in mice with Alzheimer’s disease certain immune cells that normally protect the brain begin abnormally to consume an important nutrient called arginine. By blocking this process using the drug difluoromethylornithine (DFMO), memory loss and a buildup of sticky proteins known as brain plaques were prevented. The study used a type of mouse in which a number of important genes had been swapped to make the animal’s immune system more similar to a human’s. Senior author Carol Colton, professor of neurology at the Duke University School of Medicine, and a member of the Duke Institute for Brain Sciences, said: “If indeed arginine consumption is so important to the disease process, maybe we could block it and reverse the disease.” It was previously thought the brain releases molecules that ramp up the immune system, apparently damaging the brain, but the study found a heightened expression of genes associated with the suppression of the immune system. Author Matthew Kan said: “It’s surprising because [suppression of the immune system is] not what the field has been thinking is happening in AD [Alzheimer’s disease].” © 2015 Guardian News and Media Limited
Link ID: 20802 - Posted: 04.15.2015
By James Gallagher Health editor, BBC News website Those who were overweight had an 18% reduction in dementia, researchers found Being overweight cuts the risk of dementia, according to the largest and most precise investigation into the relationship. The researchers admit they were surprised by the findings, which run contrary to current health advice. The analysis of nearly two million British people, in the Lancet Diabetes & Endocrinology, showed underweight people had the highest risk. Dementia charities still advised not smoking, exercise and a balanced diet. Dementia is one of the most pressing modern health issues. The number of patients globally is expected to treble to 135 million by 2050. There is no cure or treatment, and the mainstay of advice has been to reduce risk by maintaining a healthy lifestyle. Yet it might be misguided. The team at Oxon Epidemiology and the London School of Hygiene and Tropical Medicine analysed medical records from 1,958,191 people aged 55, on average, for up to two decades. Their most conservative analysis showed underweight people had a 39% greater risk of dementia compared with being a healthy weight. But those who were overweight had an 18% reduction in dementia - and the figure was 24% for the obese. "Yes, it is a surprise," said lead researcher Dr Nawab Qizilbash. He told the BBC News website: "The controversial side is the observation that overweight and obese people have a lower risk of dementia than people with a normal, healthy body mass index. "That's contrary to most if not all studies that have been done, but if you collect them all together our study overwhelms them in terms of size and precision." Loss of tissue in a demented brain compared with a healthy one © 2015 BBC
By Ariana Eunjung Cha Autism has always been a tricky disorder to diagnose. There’s no such thing as a blood test, cheek swap or other accepted biological marker so specialists must depend on parent and teacher reports, observations and play assessments. Figuring out a child's trajectory once he or she is diagnosed is just as challenging. The spectrum is wide and some are destined to be on the mild end and be very talkative, sometimes almost indistinguishable from those without the disorder in some settings, while others will suffer from a more severe form and have trouble being able to speak basic words. Now scientists believe that they have a way to distinguish between those paths, at least in terms of language ability, in the toddler years using brain imaging. In an article published Thursday in the journal Neuron, scientists at the University of California-San Diego have found that children with autism spectrum disorder, or ASD, with good language outcomes have strikingly distinct patterns of brain activation as compared to those with poor language outcomes and typically developing toddlers. "Why some toddlers with ASD get better and develop good language and others do not has been a mystery that is of the utmost importance to solve," Eric Courchesne, one of the study’s authors and co-director of the University of California-San Diego's Autism Center, said in a statement. The images of the children in the study -- MRIs of the brain -- were taken at 12 to 29 months while their language was assessed one to two years later at 30 to 48 months.
By Megan Griffith-Greene The idea of playing a game to make you sharper seems like a no-brainer. That's the thinking behind a billion-dollar industry selling brain training games and programs designed to boost cognitive ability. But an investigation by CBC's Marketplace reveals that brain training games such as Lumosity may not make your brain perform better in everyday life. Lumosity Brain training games, such as Lumosity, are a billion-dollar industry. Many people are worried about maintaining their brain health and want to prevent a decline in their mental abilities. (CBC) Almost 15 per cent of Canadians over the age of 65 are affected by some kind of dementia. And many people of all ages are worried about maintaining their brain health and possibly preventing a decline in their mental abilities. "I don't think there's anything to say that you can train your brain to be cognitively better in the way that we know that we can train our bodies to be physically better," neuroscientist Adrian Owen told Marketplace co-host Tom Harrington. To test how effective the games are at improving cognitive function, Marketplace partnered with Owen, who holds the Canada Excellence Research Chair in Cognitive Neuroscience and Imaging at the Brain and Mind Institute at Western University. A group of 54 adults, including Harrington, did the brain training at least three times per week for 15 minutes or more over a period of between two and a half and four weeks. The group underwent a complete cognitive assessment at the beginning and end of the training to see if there had been any change as the result of the training program. ©2015 CBC/Radio-Canada.
|By Simon Makin People can control prosthetic limbs, computer programs and even remote-controlled helicopters with their mind, all by using brain-computer interfaces. What if we could harness this technology to control things happening inside our own body? A team of bioengineers in Switzerland has taken the first step toward this cyborglike setup by combining a brain-computer interface with a synthetic biological implant, allowing a genetic switch to be operated by brain activity. It is the world's first brain-gene interface. The group started with a typical brain-computer interface, an electrode cap that can register subjects' brain activity and transmit signals to another electronic device. In this case, the device is an electromagnetic field generator; different types of brain activity cause the field to vary in strength. The next step, however, is totally new—the experimenters used the electromagnetic field to trigger protein production within human cells in an implant in mice. The implant uses a cutting-edge technology known as optogenetics. The researchers inserted bacterial genes into human kidney cells, causing them to produce light-sensitive proteins. Then they bioengineered the cells so that stimulating them with light triggers a string of molecular reactions that ultimately produces a protein called secreted alkaline phosphatase (SEAP), which is easily detectable. They then placed the human cells plus an LED light into small plastic pouches and inserted them under the skin of several mice. © 2015 Scientific American