Posts tagged asperger's syndrome

Posts tagged asperger's syndrome
Maths experts are “made, not born”
A new study of the brain of a maths supremo supports Darwin’s belief that intellectual excellence is largely due to “zeal and hard work” rather than inherent ability.
University of Sussex neuroscientists took fMRI scans of champion ‘mental calculator’ Yusnier Viera during arithmetical tasks that were either familiar or unfamiliar to him and found that his brain did not behave in an extraordinary or unusual way.
The paper, published this week (23 September 2013) in PLOS ONE, provides scientific evidence that some calculation abilities are a matter of practice. Co-author Dr Natasha Sigala says: “This is a message of hope for all of us. Experts are made, not born.”
Cuban-born Yusnier holds world records for being able to name the days of the week for any dates of the past 400 years, giving his answer in less than a second. This is the kind of ability sometimes found in those with autism, although Yusnier is not on the autistic spectrum. Unlike those with autism or the related condition Asperger’s, he is able to explain exactly how he calculates his answers – and even teaches his system and has written books on the subject.
The study, carried out at the Clinical Imaging Sciences Centre on the University of Sussex campus, suggests that Yusnier has honed his ability to create short cuts to his answers by storing information in the middle part of the brain specialised for long-term working memory (the hippocampus and surrounding cortex). This type of memory helps us carry out tasks in our area of expertise with speed and efficiency.
Although the left side of his brain was activated during mathematical problems – which is normal for all brains – the scientists observed that something slightly different happened when Yusnier was presented with unfamiliar problems.
The scans showed marked connectivity of the anterior parts of the brain (prefrontal cortex), which are involved in decision making, during the unfamiliar calculations. This supports Yusnier’s report that he was building in an extra step to his mental processes to turn an unfamiliar problem into a familiar one. His answers to the unfamiliar questions had an 80 per cent degree of accuracy (compared with more than 90 per cent for familiar questions) and his responses were slightly slower.
Dr Sigala explains: “Although this kind of ability is seen among some people with autism, it is much rarer in those not on that spectrum. Brain scans of those with autism tend to show a variety of activity patterns, and autistic people are not able to explain how they reach their answer.
“With Yusnier, however, it is clear that his expertise is a result of long-term practice – and motivation.”
She adds: “It was beyond the scope of our paper to discuss the debate on deliberate practice vs. innate ability. But our study does not provide evidence for specific innate ability for mental calculations. As put by Charles Darwin to Francis Galton: ‘ […] I have always maintained that, excepting fools, men did not differ much in intellect, only in zeal and hard work; I still think this an eminently important difference.’”
A gene linked to autism spectrum disorders that was manipulated in two lines of transgenic mice produced mature adults with irreversible deficits affecting either learning or social interaction.

The findings, published in the May 29 issue of the Journal of Neuroscience, have implications for potential gene therapies but they also suggest that there may be narrow windows of opportunity to be effective, says principal investigator Philip Washbourne, a professor of biology and member of the University of Oregon’s Institute of Neuroscience.
The research, reported by an 11-member team from three universities, targeted the impacts of alterations in the gene neuroligin 1 — one of many genes implicated in human autism spectrum disorders — to neuronal synapses in the altered mice during postnatal development and as they entered adulthood. One group over-expressed the normal gene, the other a mutated version.
Mice with higher-than-normal levels of the normal gene after a month had skewed synapses at maturity. Many were larger, appearing more mature, than normal. In these mice, Washbourne said, there were clear cognitive problems. “Behavior was just not normal. They didn’t learn very well, and they were slower to learn, but their social behavior was not impacted.”
Mice over-producing a mutated version of the gene reached adulthood with structurally immature synapses. “They were held back in development and behavior — the way they behave in terms of learning and memory, in terms of social interaction,” he said. “These were adult mice, three months old, but they behaved like normal mice at four weeks old. We saw arrested development. Learning is a little bit better, they are more flexible just like young mice, they learn faster, but their social interaction is off. To us, this looked more like Asperger’s syndrome.
"So with the same gene, doing two different manipulations — overexpressing the normal form or overexpressing a mutated form — we’ve gone to two different ends of the autism spectrum," said Washbourne, whose lab focuses on basic synapse formation and what goes wrong in relationship to autism. Work has been done in both mice and zebra fish.
"We made these mice so that we can turn the genes on and off as we want," Washbourne said. "Using an antibiotic, doxycycline, it turns off these altered genes that we inserted into their chromosomes. While on doxycycline, the mice are absolutely normal.”
However, if the inserted gene was turned off after the completion of development, mice still showed altered synapses and behavior. This result suggests that any kind of gene therapy may have to be applied to individuals with autism early on.
Effects seen in the social behavior of mice with the mutated gene, he said, are not unlike observations reported by parents of many autistic children. While normal mice prefer to engage with new mice entering their world rather than familiar others, or even a new inanimate object, these mice split their time equally. “It’s not a deficit in memory regarding which mouse is which, it’s more a weighting of their interaction. Does that mean they are autistic? I don’t know, but if you talk to parents of autistic children, one of the frustrating things they report is that their children treat complete strangers in exactly the same way that they treat them.”
While the findings provide new insights, Washbourne said, any translation into treatment could be decades away. “A problem with autism is there are many different genes potentially involved. It could be that some day, if you are diagnosed with autism, a mouth swab might allow for the identification of the exact gene that is mutated and allow for targeted therapy,” he said. “Genome sequencing already has turned up subtle mutations in lots of genes. Autism might be like cancer, with hundreds of potential combinations of faulty genes.”
(Source: uonews.uoregon.edu)