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Archive for Neuroscience & Genetics

Here you can read the news selection on Neuroscience & Genetics in the Brain Development category.

NIH Awards Grant for Language Development Research

The National Institutes of Health has awarded the University a $7.7 million, five-year grant to study the development of language among children, in order to better understand how early, preschool development relates to learning how to read.

This study will build on a longitudinal study of 60 children from a diverse set of families who already have participated in an NIH study to examine how they develop language in the home. The researchers also are studying 40 children with brain injuries, who will be followed as they enter school.

The ability to communicate using language and gestures is a uniquely human capacity,” said Susan Goldin-Meadow, the principal investigator for the study. “All children acquire language, but they do so at different rates. The goal of our project is to explore how environmental and biological factors interact to create these individuals differences. Our aim is to delineate the extent, as well as the limits, of language learning in children,” said Goldin-Meadow, the Beardsley Ruml Distinguished Service Professor in Psychology and the College.

The research is divided into four planned projects, each under the leadership of a principal investigator.

The first project will examine the effects of environmental variation on language and reading development. Janellen Huttenlocher, the William S. Gray Professor in Psychology, will be the principal investigator for this project. Rebecca Treiman, an expert on reading and the Burke and Elizabeth High Baker professor at Washington University, will work with Huttenlocher.

Huttenlocher and Treiman will look at the development of language in children in different home and school environments to learn more about the role of environment in later language development and entry into reading. Using these data, language growth curves will be constructed for each child to track language development, from the earliest stages through the child’s first years of schooling.

The second project, which Goldin-Meadow will lead, will look at gesture in these children to establish its role in revealing children’s abilities and influencing language growth.

For that project, Goldin-Meadow will explore whether children use their hands to express ideas that they cannot yet express in speech, effectively using gesture to expand their communicative range. The project will also examine individual differences in how children use gesture, focusing on whether those differences predict later language use. Finally, the project will explore whether gesturing plays a role in helping children learn language.

Susan Levine, Professor in Psychology and the College, will lead the third project, which will focus on language and reading development in children with brain injuries to examine the combined effects of biological and environmental variations on learning.

The researchers will examine the plasticity of language and reading skills, studying children ages 5 to 10 who experienced a brain injury before or around the time of birth. By assessing language and reading development in the school year, they will be able to determine whether plasticity for early language extends to reading and more complex language processes. The researchers also will try to determine if environmental variation plays the same role in predicting language growth in brain-injured children as it does in children without a brain injury.

Steven Small, Professor in Neurology, Psychology and the College, is principal investigator for the fourth project, which will look at the brain organization underlying language processing and the effect of environmental and biological variation.

That project will look at the organization of language functions in both typically developing children and children who suffered early brain injuries. Children will have functional brain imaging to evaluate brain development for language and gesture. These fMRI scans will be used to understand how parts of the brain that are used for language interact and adapt as children (with and without brain injuries) refine their language skills and learn to read.

Another important feature of the study is the development of robust statistics to support the work. Stephen Raudenbush, the Lewis-Sebring Distinguished Service Professor in Sociology and Chair of the Committee on Education, and Larry Hedges, the Board of Trustees professor of statistics and social policy at Northwestern University, will lead this effort.

Raudenbush pointed out the importance of these projects and the potential for obtaining new information about how children learn.

“This will be the first study to show how language development beginning during the second year of life is linked to the emergence of reading comprehension and oral language that are key to later school success,” he said. “The study will generate new ideas about how to improve preschool and primary school instruction.”

Source: University of Chicago Chronicle
http://chronicle.uchicago.edu/080612/nih.shtml

13 June, 2008. 2:44 PM. Link | Comments: No Comments »

Scientists Reveal Dangers of Older Fathers

Children are almost twice as likely to die before adulthood if they have a father over 45, research has shown.

A mass study found that deaths of children fathered by over-45s occurred at almost twice the rate of those fathered by men aged between 25 and 30.

Scientists believe that children of older fathers are more likely to suffer particular congenital defects as well as autism, schizophrenia and epilepsy. The study was the first of its kind of such magnitude in the West, and researchers believe the findings are linked to the declining quality of sperm as men age.

A total of 100,000 children born between 1980 and 1996 were examined, of whom 830 have so far died before they reached 18, the majority when they were less than a year old.

The deaths of many of the children of the older fathers were related to congenital defects such as problems of the heart and spine, which increase the risk of infant mortality. But there were also higher rates of accidental death, which the researchers believe might be explained by the increased likelihood of suffering from autism, epilepsy or schizophrenia.

Most research into older parents has, until now, focused on the risks passed on by older mothers. But the new study, published in the European Journal of Epidemiology, was adjusted to take account of maternal age and socio-economic differences.

The research also found higher death rates among children of the youngest fathers, especially those below the age of 19. However, the study said these differences were explained by the risks of teenage motherhood and poorer diet and lifestyle.

Previous research using the same data found that older men were four times as likely to father a child with Down’s syndrome, while other studies have found that the genetic quality of sperm deteriorates as men age.

More than 75,000 babies in Britain are born to fathers aged 40 and over each year, or more than one in 10 of all births. This includes more than 6,000 born to fathers aged 50 or over. The average age of fathering a child in this country is 32.

Dr Allan Pacey, senior lecturer in andrology – the medical specialty dealing with male reproduction – at the University of Sheffield, said: “A lot of people know that there are risks for the child that come from having an older mother, but children of older fathers also carry an increased risk. These sorts of results provide another good reason to have children early, when possible.”

Dr Pacey, who is secretary of the British Fertility Society, said scientists were unsure exactly what impact the ageing process had on the quality of sperm, making it impossible to detect defects before conception.

Dr Jin Liang Zhu, from the Danish Epidemiology Science Centre, which carried out the research, said: “The risks of older fatherhood can be very profound, and it is not something that people are always aware of.

The mother’s age still has the bigger impact on child health, however. About one in 900 babies born to women under 30 have Down’s syndrome – a figure which reaches one in 100 by the age of 40. The number of over-40s giving birth in Britain each year has doubled in the past decade to 16,000. The risk of miscarriage rises sharply with age.

Source: Telegraph.co.uk, United Kingdom
http://tinyurl.com/4jl4jy

1 June, 2008. 9:45 AM. Link | Comments: No Comments »

Brain Activity Reveals Mother Tongue

No one can read our thoughts, for now, but some scientists believe they can at least figure out in what language we do our thinking.

Before we utter a single word, experts can gauge our mother tongue and the level of proficiency in other languages by analyzing our brain activity while we read, scientists working with Italy’s National Research Council say.

For more than a year, a team of scientists experimented on 15 interpreters, revealing what they say were surprising differences in brain activity when the subjects were shown words in their native language and in other languages they spoke.

The findings show how differently the brain absorbs and recalls languages learned in early childhood and later in life, said Alice Mado Proverbio, a professor of cognitive electrophysiology at the Milano-Bicocca University in Milan.

Proverbio, who led the study, said such research could help doctors communicate with patients suffering from amnesia or diseases that impair speech. It could also be of use one day in questioning refugee applicants or terror suspects to determine their origin, she said.

The interpreters who took part in the study were all Italians working for the European Union and translating in English and Italian.

“They were extremely fluent in English,” Proverbio said in a telephone interview earlier this month. “We didn’t expect a big difference in brain activity” when they switched from one language to another.

The subjects were asked to look at a screen that flashed words in Italian, English, German as well as nonsensical letter combinations. They were not aware of the purpose of the study and were simply tasked with pressing a button when they spotted a specific symbol, Proverbio said.

Meanwhile, researchers monitored them using an electroencephalograph, or EEG, which measures the brain’s electrical activity through electrodes placed on the scalp. The EEG readout was fed into a computer program that pinpointed the time, intensity and location of the responses evoked in the subjects’ brains by each word.

About 170 milliseconds after a word was shown, the researchers recorded a peak in electrical activity in the left side of the brain, in an area that recognizes letters as part of words before their meaning is interpreted.

These brain waves had a much higher amplitude when the word was in Italian, the language the interpreters had learned before age five.

The research suggests the differences between the two languages are at a very fundamental level,” said Joseph Dien, a psychology professor at the University of Kansas who was not involved in the study.

Proverbio attributed the differences to the fact the brain absorbs the mother tongue at a time when it is also storing early visual, acoustic, emotional and other nonlinguistic knowledge. This means that the native language triggers a series of associations within the brain that show up as increased electrical activity.

“Our mother tongue is the language we use to think, dream and feel emotion,” Proverbio said.

Offering an example, she said that an English-speaking child would associate the word “knife” with a sharp, cold object that is dangerous and should only be used by adults, while these links would be much weaker and indirect once that person learned the same word in another language later in life.

The only exception would be for those bilingual individuals who learn an extra language before age five.

The findings by Proverbio’s team were published earlier this year in the Biological Psychology journal and have surprised some scientists, particularly because the differences in brain activity show up at a point in the thought process when the brain hasn’t yet interpreted the meaning of the words.

“I didn’t expect such differences at the very beginning of the process,” Dien said in a telephone interview.

“They emerge at a very early level of comprehension,” he said. “It will take a lot more work to work out the implications of that.”

Dien said further research in the area could help understand and treat learning disabilities like dyslexia.

The Italian study also showed links between brain activity and proficiency in other languages. The differences showed up when the translators were shown words in English and in German, a language they knew at a more basic level, Proverbio said.

In this case, the differences in intensity and duration of the brain’s activity were seen some 250 milliseconds after a word was shown, and were traced to areas of the brain used to understand the meaning of words.

This phenomenon had been already discovered by previous studies which, however, had not spotted any difference between the mother tongue and other languages spoken with high proficiency. This had suggested that with some effort “we could all become perfectly bilingual,” Proverbio said. “Unfortunately, that’s not true.”

Source: International Herald Tribune, France
http://tinyurl.com/45dzks

23 May, 2008. 8:55 AM. Link | Comments: No Comments »

Research Sparks Push for Earlier Schooling

A tide of recent research on early childhood development is inspiring prominent scientists and politicians to argue for an unprecedented investment in schooling that begins virtually at birth.

But as decades of academic studies on brain development start to land in the real world, experts are divided on whether to focus new funding on infants and toddlers, or conventional preschool. Many now think some policies popular with politicians and the public, such as universal prekindergarten, may fail to reach at-risk kids at a young enough age.

The scientific controversy also is spilling into the presidential contest, where the Democratic candidates have taken divergent positions on universal preschool and other early childhood issues.

Studies have suggested that intervening before children start preschool improves academic outcomes for low-income kids and may reduce the risk that they will end up in prison. Such interventions stem from the theory that experiences in the first five years of life set a lifelong course for brain development.

Chicago has become a national proving ground for schooling during the first three years and is home to prominent advocates such as Nobel Prize-winning economist James Heckman of the University of Chicago, who said reaching kids before preschool could offer the best long-term economic return.

Even at age 4 or 5, you may be starting too late,” Heckman said. “I wouldn’t say it’s hopeless to help kids after those early years, but it’s extremely expensive.”

Backers of universal preschool say the evidence for even earlier intervention is not yet solid and offering conventional prekindergarten to everyone would help build popular support for early education.

In theory, starting to intervene soon after birth should help kids more because that’s when experience starts to shape their brains, many experts said.

Children’s brains change more between conception and kindergarten than at any other time. University of Chicago neuroscientist Peter Huttenlocher showed in studies over the last 30 years that connections between cells in most brain areas peak by age 3, then decline gradually as experiences mold the brain’s circuitry.

The zero-to-3 period is not necessarily a magical and irreplaceable window for teaching children. But studies show that babies raised in poverty get fewer of the early experiences that spur vocabulary growth and good social judgment, making it harder for them to catch up later.

For example, toddlers whose parents speak more words to them develop bigger vocabularies than children who hear less speech, studies have found. One University of Kansas study concluded that kids from upper-income backgrounds hear 30 million more words by age 3 than those from poor families.

Early intervention with enrichment programs can narrow that gap, researchers and advocates say.

“The basic science of brain development says you need to start as early as possible for kids in the greatest danger to get the best outcomes,” said Jack Shonkoff, director of the Center on the Developing Child at Harvard University.

Bruce Fuller, a professor of education and public policy at the University of California-Berkeley, said he feared focusing on universal prekindergarten — making preschool a middle-class entitlement — could divert help from low-income families that need it most.

“Why would we use scarce public dollars to subsidize all families if we know the biggest impact is with poor kids?” he said.

Source: Detroit Free Press, United States
http://www.freep.com/apps/pbcs.dll/article?AID=/20080502/NEWS07/805020328

4 May, 2008. 10:35 AM. Link | Comments: No Comments »

How the Brain Learns to Read Can Depend on the Language

For generations, scholars have debated whether language constrains the ways we think. Now, neuroscientists studying reading disorders have begun to wonder whether the actual character of the text itself may shape the brain.

Studies of schoolchildren who read in varying alphabets and characters suggest that those who are dyslexic in one language, say Chinese or English, may not be in another, such as Italian.

Dyslexia, in which the mind scrambles letters or stumbles over text, is twice as prevalent in the U.S., where it affects about 10 million children, as in Italy, where the written word more closely corresponds to its spoken sound. “Dyslexia exists only because we invented reading,” said Tufts University cognitive neuroscientist Maryanne Wolf, author of Proust and the Squid: The Story and Science of the Reading Brain.

Among children raised to read and write Chinese, the demands of reading draw on parts of the brain untouched by the English alphabet, new neuroimaging studies reveal. It’s the same with dyslexia, psychologist Li Hai Tan at Hong Kong Research University and his colleagues reported last month in the Proceedings of the National Academy of Sciences. The problems occur in areas not involved in reading other alphabets.

Using two brain-imaging techniques, they identified striking differences in neural anatomy and brain activity between children able to read and write Chinese easily and classmates struggling to keep pace. Both were at odds with patterns of brain activity among readers of the English alphabet.

Even when readers in both languages looked at the same written characters, the brain activity was different, other researchers found. Arabic numerals of standard arithmetic — used by readers of Chinese and English alike — activate different brain regions depending on which of the two languages people had first learned to read, researchers at the Chinese Academy of Sciences and China’s Dalian University of Technology reported in 2006.

“In this sense, we may regard dyslexia in Chinese and English as two different brain disorders,” Dr. Tan said, “because completely different brain regions are disrupted. It’s very likely that a person who is dyslexic in Chinese would not be dyslexic in English.”

By any measure, reading is a complex and peculiar task. At the speed of thought, readers of English turn letters they see into sounds, sounds into words, and words into meaning. Fluency is measured in milliseconds. Spelling variations are speed bumps in the brain.

Until recently, researchers who study reading abilities focused mostly on Western alphabets. English and 218 other languages, from Alsatian to Zulu, share variations of the same Latin character set. But that set is only one of 60 writing systems used among the world’s remaining 6,912 spoken languages. Even so, those studies convinced many scientists and educators that the brain’s response to the written word, regardless of the language, is universal.

The new research suggests they’re wrong. The schooling required to read English or Chinese may fine-tune neural circuits in distinctive ways.

To learn the ABCs of English, we essentially harness our listening skills to a phonetic code. To become literate in Chinese, however, we must make much heavier use of memory, motor control and visual-perception circuits located toward the front of the brain. Children can master the 6,000 or so Chinese characters used in Mandarin and Cantonese text only by laboriously copying them out over and over again, until each abstract form becomes second nature.

“We have to recognize that the writing system in China is different, the demands on the brain are different and the characteristics of dyslexia are different,” said Georgetown University pediatric learning specialist Guinevere Eden, who is incoming president of the International Dyslexia Association.

To document the effects on brain development, Dr. Eden and her colleagues are launching a five-year study in Beijing and Washington to compare the neural changes in 60 schoolchildren learning to read either Chinese or English. “Nobody has ever done this across two writing systems,” Dr. Eden said.

In ways that ancient scribes never imagined, text has transformed us. Every brain shaped by reading, whether it is schooled in Chinese or English text, measurably differs — in terms of patterns of energy use and brain structure — from one that has never mastered the written word, comparative brain-imaging studies show. “There are real differences that emerge because of literacy,” Dr. Wolf said.

Some social psychologists speculate that the brain changes caused by literacy could be involved in cultural differences in memory, attention and visual perception. In January’s Psychological Science, MIT researchers reported that European-Americans and students from several East Asian cultures, for example, showed different patterns of brain activation when making snap judgments about visual patterns.

No one knows which came first: habits of thought or the writing system that gave them tangible form. A writing system could be drawn from the archaeology of the mind, perpetuating aspects of mental life conceived at the dawn of civilization.

“Once you have different writing systems in place,” said University of Michigan social psychologist Richard Nisbett. “They may reinforce the perceptual and cognitive trends that preceded the invention of writing. They may go hand in glove.”

Source: Wall Street Journal
http://tinyurl.com/6c4gax

2 May, 2008. 8:21 AM. Link | Comments: No Comments »

Raising a Little Genius

What does my baby know? When does my baby start to learn? How do you teach a baby?

Twenty-five years ago, the answers to these questions were unclear; there was much conjecture and many hypotheses on just what happens when infants interact with the people and objects in their environment. Observation and testing provided many tantalizing clues, but what was actually going on within those precious little heads still remained a mystery.

In recent years, new and nonintrusive brain-scanning technology has allowed scientists to watch in real time the brain-stimulation effects of a wide range of seemingly simple activities, beginning in the earliest weeks of life.

Thanks to pioneering work by scientists such as Patricia Kuhl and Andrew Meltzoff at the University of Washington’s Institute for Learning and Brain Sciences, we have learned that each parent-infant interaction, no matter how silly or inconsequential it may seem at the moment, is an exchange of multiple, complex messages and triggers quite specific cerebral activity.

It turns out, infants quickly know an amazing amount of things: Just days after birth, they can recognize familiar faces, smells and sounds; soon after birth they can differentiate every vocal sound produced by human languages (and by six months they have already begun to sort out the common sounds of the languages they hear most frequently). At birth, they begin expressing rudimentary emotional expressions, and by two months they can express more complex emotions, such as sadness or frustration.

While these infants are literally growing smarter daily, their parents are often feeling the opposite effect; the addition of this little genius to the family has thrown their personal and family routines into disarray, priorities are now inverted and diapers and feeding cycles are an obsession they never believed they’d share. All parents need and deserve support in this time of transition.

What to do with this information is the challenge; for many parents in today’s two-wage-earner economy, just spending a few waking hours with their baby is a stretch — especially when it is the baby’s sleep schedule that determines when a waking hour occurs.

While we’d all like to give our littlest ones every advantage from day one, parents are overwhelmed with opinions, options and advice, much of it contradictory.

Every nervous new parent wants the best for his or her child, but there are no owner’s manuals, no quick-install instructions, and no help desk open at 4 a.m. New parents are often isolated, beginning this new adventure on their own, especially when living far away from their families and friends.

New parents can prepare to be their child’s first and best teacher by first acknowledging that none of us can do this alone. Connecting with their peers to share the challenges and opportunities, acknowledging their common needs and sharing resources, information and skills will build confidence and competence in those critical first few months of the adventure of parenting.

Source: Seattle Times, United States
http://seattletimes.nwsource.com/html/opinion/2004371716_harryhoffman25.html

26 April, 2008. 8:40 AM. Link | Comments: No Comments »

Study Captures Brain’s Activity Processing Speech

Research is First to Describe How Neurons Interpret Different Words

You might be able to hear the difference, but to many children and adults, these words sound exactly the same. The problem isn’t that they can’t hear the sounds. The problem is that they can’t tell them apart.

One in 20 children in kindergarten has difficulties understanding speech that are not related to hearing or problems with their ears. The reason is that speech discrimination is a problem solved in the brain, not in the ear. How does the brain process speech sounds? Very little was known, until now.

Enter Dr. Michael Kilgard and Crystal Engineer. Kilgard is a neuroscientist in the School of Behavioral and Brain Sciences at the University of Texas at Dallas. His lab is one of the few in the world that studies how individual neurons process speech stimuli. Engineer is one of Professor Kilgard’s doctoral students. Together they conducted a study to provide the first-ever description of how speech sounds are processed by neurons in the brain. This insight may offer a new approach to treating children with speech processing disorders.

Now that we’ve cracked the door on this important problem, we should be able to understand the neural basis of many common speech processing disorders and use this information to develop new treatments,” said Dr. Kilgard.

The study is part of Engineer’s dissertation, “Cortical activity patterns predict speech discrimination ability,” and will be published in the May issue of Nature Neuroscience, the top research journal in the field of neuroscience. The advance, online publication of the study is now available on the Nature Neuroscience Web site.

This research is groundbreaking for a number of reasons. Prior studies have used a synthetic voice and tested the response to only a few words. Engineer and Kilgard had a much broader scope. They tested all the consonant sounds in the English language using a human voice. Microelectrodes inserted into a rat’s auditory cortex enabled the researchers to capture the patterns of neural activity generated by each consonant with incredible precision. Recording techniques that can be used with human subjects (such as MRI and EEG) lack the precision to track the activity of individual neurons.

The recordings showed that contrary to prior belief it’s not the quantity of neurons that fire in response to a speech sound that is important. It is which neurons are firing and exactly when they are firing – down to the millisecond – that is critical.

Based on the patterns of activity shown in the neural recordings, Kilgard and Engineer believed they could predict the rats’ ability to discriminate the speech sounds. They hypothesized that speech sounds that generate similar patterns of neural activity would be impossible for the brain, and thus the rat, to tell apart. In contrast, speech sounds that generate dissimilar patterns would be easy for rats to tell apart.

To test their theory, they trained rats to press a lever in response to some speech sounds and not others. Although rats can’t talk and certainly don’t have language, the new study reveals that rats can easily hear the difference between most speech sounds. The auditory system in rats and many other animals are surprisingly similar to humans’.

For example, the neural responses for the words dad and sad are very different. (See video.) As expected, rats can easily distinguish between these two words. The neural responses for the words rad and lad are very similar. Not surprisingly, rats, like many children, find it very difficult to differentiate between these two words.

The neural patterns explain the rats’ ability to differentiate between different speech sounds. “Our study is the first to tie the perception of speech sounds to the neural response of the same sounds,” said Engineer.

So, they’ve cracked the code, now what? The implications are huge. The perception of speech sounds is important because these are the acoustic building blocks of language. Scientists couldn’t begin to isolate the problems with speech and hearing disorders until they understood how speech sounds are normally processed in the brain.

Already, one of the most cited researchers in the world on neuroplasticity, the brain’s ability to change, Kilgard has big plans for his UT Dallas students and lab. He not only tackles ambitious topics in neuroscience, but in the process, he creates hands-on opportunities for his students at every level to get involved. This is what inspired Engineer to pursue her Ph.D.

“Dr. Kilgard encourages undergraduates to follow their interests. They have the rare opportunity to initiate and run their own projects and publish in prestigious journals. If it weren’t for these opportunities, I wouldn’t have gone on to graduate school,” said Engineer. She has worked with Kilgard since 2003, as an undergraduate, and expects to complete her Ph.D in August.

The emphasis on student involvement is illustrated by the number and diversity of the authors listed on the Nature Neuroscience study. Engineer and Kilgard’s research team included master’s students Claudia Perez and Helen Chen; undergraduates Ryan Carraway and Kevin Chang; and Ph.D. students Amanda Reed, Jai Shetake and Vikram Jakkamsetti.

“This paper in Nature Neuroscience is a great testimony to the level of graduate education students receive at UT Dallas. Dr. Kilgard is a wonderful mentor who helps students develop into independent researchers,” said Dr. Bert Moore, dean of the School of Behavioral and Brain Sciences. “We are proud of both Crystal and Mike for this exciting research.”

Source: University of Texas at Dallas, TX
http://www.utdallas.edu/news/2008/04/23-001.php

23 April, 2008. 8:29 AM. Link | Comments: No Comments »

The Sex Divide

The kiwi classroom of the future could look a little like this, if American educationalist Dr Leonard Sax has any influence.

A room is filled with 7-year-old boys, none of whom is sitting - in fact there are no chairs on offer.

Their teacher is pacing the room, moving unpredictably and virtually shouting at the children. Occasionally he will eyeball one of the students, get right up into his face and talk at him in a confrontational manner.

There is noise, cooler light and the temperature has been turned down. This, says Sax, is the environment in which boys learn best.

The Maryland-based executive director of the National Association for Single Sex Public Education, is in New Zealand next month to speak at several single sex schools including Auckland’s St Cuthbert’s College and Dilworth School, and at Iona College, Lindisfarne College and Woodford House, Hawke’s Bay.

Citing research from Harvard Medical School, the US National Institute of Health and various European studies, Sax argues that no one-size-fits-all education programme can be successfully applied across the sex divide, that both girls and boys will flourish in environments tailored to their gender-specific requirements.

Traditional arguments for sex-segregated schools are often based broadly on the management of teenage hormones. The theory was there would be less distraction for everyone if the girls and boys were educated separately. But hormones have no part in today’s rationale for single-sex classes.

“There’s been a pretty fundamental shift in the way people think about single-sex education, at least in North America, over the last 20 years or so,” says Sax. “That’s what’s new: the idea that the single-sex format may be most beneficial for children who are 5, 6, 7 years old. This is the empirical finding.”

Of the 367 public schools in the US that have adopted the single-sex format in the past few years, Sax says that all but about 20 are primary schools.

[I’m] not saying that there are not benefits at the high school level; there certainly are. But the benefits in the early primary years are much greater.

He says advanced imaging techniques have offered neuroscientists fresh insights into brain development.

When you compare a six-year-old girl with a six-year-old boy, you find quite staggering differences in the brain,” says Sax.

Regions of the brain develop in a different sequence in the genders, he says.

The areas of the brain associated with language and fine motor skills mature about six years earlier in girls than boys. The areas of the brain associated with maths and geometry mature about four years earlier in boys than girls. This finding may help explain why some girls find maths “hard”, he says, while some boys think poetry is for “sissies”.

According to Sax, understanding and exploiting these nuances allow educators to adapt lessons and classrooms to suit the all-girl or all-boy population.

One “very reliable difference” between 6-year-old boys and 6-year-old girls is in their ability to sit still and be quiet. The average girl can sit still for longer than the average boy, with implications for the duration of lessons and the structure of the day, says Sax. Girls can have longer, uninterrupted classes, but boys will do best with 20-minute lessons followed by a run around outside.

Some US schools have taken this finding a step further. At both Cunningham School for Excellence, Iowa, and Foley Intermediate, Alabama, sitting is optional in the all-boys classes. And Chicago’s Hardey Prep doesn’t even supply chairs to their 6 and 7-year-old boys.

“As one teacher said to me: when that boy sits down his brain shuts off,” says Sax. “So the boys stand for many of the classes.

“You’ll find many, many boys’ primary schools make sitting optional. Many boys at age 6 learn better when they’re standing than they do when they’re sitting.”

Girls, on the other hand, generally work better when they’re sitting.

“In the mixed classroom, every choice you make is going to advantage the girls at the expense of boys or advantage the boys at the expense of girls,” he says. “The lack of awareness of gender differences often has the unintended consequence of disadvantaging both the girls and the boys.”

But Sax’s theories relate not only to the type of lesson, but to the environment the students work best in.

He says studies of young people of normal weight have shown that the ideal room temperature for boys to learn is about 20C; for girls it’s about 3 degrees higher. With classroom thermostats typically set at somewhere between 21C and 22C, Sax says that both genders will be outside their ideal comfort zone.

Similarly, he says, a European study has shown that girls and boys learn better under different levels of fluorescent lighting. Girls learn much better with 3000-kelvin bulbs (warm light) while boys learn much better with 4000-K bulbs (cool light).

Evidence that tailoring the learning experience rather than simply splitting up boys and girls enhances academic performance is mounting, with research showing improved grades and test results in both sexes.

Sax advocates the introduction of single-sex classes into co-ed schools as some New Zealand schools are already doing. In Auckland’s Mt Albert Grammar, most of the junior classes are gender segregated while Long Bay College in Auckland last year introduced single-sex classes.

Sax says he wasn’t always a devotee of single-sex education, believing that “we live in a co-ed world… schools should prepare kids for the real world”. And there are still many critics of the single-sex education model, notably the American Civil Liberties Union and the National Organisation for Women, who see it as a discriminatory anachronism. Under the old model that prevailed in the US until around the 1960s, boys’ schools typically received the bulk of the resources while girls’ schools made do with their leftovers and hand-me-downs.

But Sax has no intention of returning to what he describes as “the bad old days”. He was educated in an era when “they pushed girls and boys into pink and blue cubby holes” - boys had compulsory woodwork, girls had home economics. The new world order he favours aims to “expand educational horizons, to get more girls excited about computer science and physics and engineering - and to get more boys excited about art and poetry and creative writing and foreign languages“.

The irony is that we’ve had roughly three decades throughout the English-speaking world of ignoring gender, pretending that gender doesn’t matter,” he says.

There are substantially fewer young women studying computer science, physics and engineering than there were 20 years ago - and fewer men who regard creative writing, or writing at all, as something that boys do. So we’ve ignored gender and the result of ignoring gender has been not to eliminate gender stereotypes; it has been a hardening of gender stereotypes.

New Zealand Herald, New Zealand
http://www.nzherald.co.nz/category/story.cfm?c_id=35&objectid=10505122

21 April, 2008. 9:05 AM. Link | Comments: No Comments »

Autism Myth Lives On

Why people continue to blame vaccines, despite evidence to the contrary.

As the brother of an autistic person and a brain scientist, I have been hoping that the increased focus on autism in the news would lead to a greater public understanding of this disorder. Instead, I am angry that this coverage is spreading dangerous myths.

My sister, Karen, is autistic. In the 1970s, my parents wondered why she behaved so differently. At the time, a prevalent idea was that an emotionally distant mother could somehow prevent a child from understanding emotions or relating normally to others. Our parents had a simpler idea, that they might have hurt Karen’s head during a bath.

Both these ideas are wrong. Autism is a neurological disorder, and its signs appear by the age of 1 or even earlier. It is highly inheritable. In identical twins where one is autistic, the chance that both are autistic is greater than 50-50. Even non-identical twins and siblings are at increased risk. In short, I dodged a genetic bullet. Now I worry about my daughter.

A link that isn’t there

Recently, celebrities such as Jenny McCarthy and other activists have taken to the airwaves to repeat the myth that autism is linked to vaccination. Although peer-reviewed scientific evidence overwhelmingly opposes their views, they have attracted attention. In a recent discussion on Larry King Live, three pediatricians invited to make the case for science were no match for McCarthy’s star power. Situations like this could mistakenly persuade parents to leave their children unvaccinated and vulnerable to contagious diseases.

Speculation about a vaccine-autism link began with a 1998 uncontrolled study of a few autistic children. But the conclusions were later retracted. Subsequent speculation focused on the compound thimerosal. But removing it from all routine childhood vaccines in the USA, Denmark, Sweden and Canada has not decreased autism rates.

What are McCarthy’s credentials? She is an actress and comedienne — with an autistic son. Her career took on new life after she wrote a best-selling pregnancy guide. Like all parents of autistic children, she wrestled with the question of what caused his disorder. She recalled that her son was vaccinated about the time his symptoms first appeared. Aha! That’s it. Here is an example of her reasoning: “I believe that parents’ anecdotal information is science-based information.”

How we’re wired

Although her concept of evidence is flawed, I don’t blame her. The error highlights how our brains are wired to think. Like the authors of the 1998 study, she concluded that two events happening around the same time must be linked. They used the principle that coincidence implies a causal link. But there was no coincidence for her son: He was born in 2002, after thimerosal was removed from vaccines.

The problem is compounded by “source amnesia,” in which people are prone to remember a statement without recalling where they heard it or whether the source was reliable. Presidential candidate John McCain might have fallen prey to source amnesia when he repeated the vaccine-autism myth last month. Recollection is more likely when the “fact” fits previously held views; parents might already dislike vaccinations based on their kids’ reaction to shots. But when it comes to a complex issue such as autism, such errors of reasoning hinder us from distinguishing real causes from coincidences.

Out of sight of the cameras, increased research funding is spurring efforts to find autism’s causes. Scientists are vitally interested in possible environmental influences. But the vaccine story is a dry well. Working on it further wastes valuable time and resources. It’s time to dig elsewhere.

As I watch my beautiful 10-month-old daughter grow, I wish that preventing autism were as simple as withholding a few injections. But along with my wife, a physician, I understand the vital importance of vaccination, not only for maintaining our baby’s health but also protecting our community from infectious diseases. Our daughter’s next shots are in two months.

Sam Wang is an associate professor of molecular biology and neuroscience at Princeton University. He is a co-author of Welcome to Your Brain: Why You Lose Your Car Keys But Never Forget How to Drive and Other Puzzles of Everyday Life.

Source: USA Today
http://blogs.usatoday.com/oped/2008/04/autism-myth-liv.html

16 April, 2008. 8:03 AM. Link | Comments: No Comments »

Mapping Genetic Abnormalities in Autism

A new project to study the brains of people with autism in unprecedented detail could finally pinpoint subtle neurological changes that underlie the disorder. Researchers will use an innovative set of tools developed to study gene expression to analyze exactly where early brain development goes awry.

“The technology now exists to be able to examine in fine detail the organization of brain cells–for example, whether brain cells have their proper number and position,” says Eric Courchesne, a neuroscientist at the University of California, San Diego, who is leading the project. “This could provide a major insight into the cause of autism.

Autism is a neurodevelopmental disorder characterized by deficits in language and social behavior. While the brains of people with autism appear broadly normal, previous brain-imaging studies have revealed unusual growth patterns in very young children with the disorder. “It’s clear that in the first two years of life, the brain grows too large, too fast,” says Courchesne.

Scientists don’t yet understand the reason for the strange growth spurt–whether it’s caused by too many neurons in a particular part of the brain or a failure to prune extraneous neurons, a common occurrence in normal development. They hope that an unusual set of tools developed for the Allen Brain Atlas, a database of gene expression in the mouse brain, could finally yield clues.

To create the map, researchers at the Allen Institute for Brain Science in Seattle, WA, painstakingly created a comprehensive set of DNA probes that highlight the expression patterns of individual genes. While previous studies have only been able to look at the expression of a handful of genes at a time, these probes can provide a wealth of information by revealing the expression of many genes simultaneously.

Researchers at the Allen Institute have been sifting through the toolbox for probes that can identify different cell types in the human cortex–the most recently evolved part of the brain. The team will use them to study the expression of approximately 25 genes in samples of postmortem brain tissue collected from very young children with autism. “This will give us a much clearer look at how things are disorganized, rather than just saying they are disorganized,” says Ed Lein, director of neuroscience at the Allen Institute.

The researchers will focus on the prefrontal cortex, an area in the frontal lobes involved in higher-order social and emotional communication, and one of the brain regions most affected by abnormal early overgrowth. The DNA probes will allow researchers to compare the location and organization of specific cell types, such as excitatory neurons that connect to brain areas outside of the cortex and inhibitory neurons that form local cortical circuits.

It’s fundamentally important to identify the cause of that overgrowth,” says Courchesne. “It may help us understand how best to tailor interventions for autism, not just behaviorally, but for medical and chemical interventions down the road.”

The project will be the first to use the tools developed at the Allen Institute to study the neurobiology of human disease. The data will be made publicly available via the Web for other scientists to study, as data from the mouse brain study is now.

Source: MIT Technology Review, MA
http://www.technologyreview.com/Biotech/20557/

12 April, 2008. 8:42 AM. Link | Comments: No Comments »

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