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Do supercharged brains give rise to autism?

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IMAGINE a world where every sound jars like a jackhammer, every light is a blinding strobe, clothes feel like sandpaper and even your own mother’s face appears as a jumble of frightening and disconnected pieces. This, say neuroscientists Kamila and Henry Markram of the Swiss Federal Institute of Technology in Lausanne, is how it feels to be autistic.

According to their “intense world” hypothesis, all of autism’s baffling and sometimes incongruous features – social problems, language impairment and obsessive behaviour, sometimes allied to dazzling savant abilities – can be explained by a single neurological defect: a hyperactive brain that makes ordinary, everyday sensory experiences utterly overwhelming.

If they’re right – and the idea is generating a deal of interest among autism experts – the husband-and-wife team could be on course to add a significant new theory to autism research. “It is a very compelling idea,” says neurobiologist Asaf Keller at the University of Maryland School of Medicine in Baltimore, who has arranged a symposium to discuss it at November’s Society for Neuroscience meeting in Washington DC.

Recognition of sensory disturbance in autism goes back as far as the 1940s, and today it is widely seen as a fundamental aspect of the condition. “There is a lot of evidence for sensory hypersensitivity,” says Simon Baron-Cohen, director of the Autism Research Centre at the University of Cambridge. He notes that hypersensitivity can affect the vision, hearing and touch of people with autistic spectrum disorders (ASD, see “Autism basics”).

“If you talk to practitioners, invariably they will say, ‘I’ve never seen a child with autism who doesn’t have sensory problems’,” adds Keller. “There’s a strong correlation, maybe 100 per cent.”

The Markrams, however, are the first to put sensory overload at the heart of the condition. “Our hypothesis is that autistic people perceive, feel and remember too much,” says Kamila Markram. Faced with this blooming, buzzing confusion, autistic infants withdraw, with serious consequences for their social and linguistic development. Repetitive behaviours such as rocking and head-banging, meanwhile, can be seen as an attempt to bring order and predictability to a blaring world (Frontiers in Neuroscience, vol 1, p 77).

Most theories of autism assume the affected person has a neurological deficit of some kind – that some part of their brain isn’t working properly (see “Five leading theories of autism”). According to the Markrams’ theory, though, the brain isn’t underperforming but overperforming.

System overload

Along with colleague Tania Rinaldi, they developed their hypothesis largely from work on an animal model of autism, plus human brain imaging, autopsy evidence and the subjective experiences of people with ASD, including Henry Markram’s son who is borderline autistic. “That’s the curse of having parents who are neuroscientists, they are constantly analysing you,” says Kamila Markram. She has observed the boy’s intense fears and anxieties and his struggles with oversensitivity.

For the animal work they used an autism model called the VPA rat. This model is based on dozens of case studies of children whose mothers took the anticonvulsant and mood-stabilising drug valproic acid (VPA) while pregnant. A frighteningly high proportion of these children ended up with some form of autism – around 10 per cent, compared with some 0.08 per cent of the general population.

In the mid-1990s, researchers working on the adverse effects of VPA tried exposing rat fetuses to the drug and found that giving it on the 12th day of gestation – equivalent to the early part of the first trimester in humans – caused major damage to the rats’ developing brainstem. This has far-reaching effects on later brain development and results in socially withdrawn behaviour that looks eerily similar to humans with autism. The VPA rat is now an established animal model of autism.

When the Markrams examined the brains of VPA rats in minute detail, they found that they didn’t just share behavioural traits with autistic humans. Their neuroanatomical changes were similar too.

One of the most replicated findings in autism neurology is abnormal brain growth. At birth the brains of autistic children are small or normal sized, but grow unusually quickly. By age 2 to 3 their brain volume is roughly 10 per cent larger than average. Human autopsy findings by Manuel Casanova of the University of Louisville in Kentucky suggest that part of this extra volume consists of structures called minicolumns in the brain’s outer layer, the cerebral cortex.

You can think of minicolumns as the brain’s microprocessors: clusters of around 80 to 120 neurons that crunch basic neural information, including perception, memory and so on, before it is somehow integrated into a whole. They are the smallest independent processing units in the cortex.

When the Markrams looked at minicolumns in VPA rats they saw some striking changes similar to the human autopsies. First and foremost the minicolumns were unusually abundant. They were also extraordinarily well connected. “Using a technique for recording directly from neurons, we found consistently, over many experiments, that these circuits are hyperconnected,” says Kamila Markram. Each minicolumn neuron in a VPA rat has up to 50 per cent more connections than normal and this causes them to be hyper-reactive, firing more readily when stimulated by an external electrical current. The circuits are also “hyperplastic”, meaning they form connections with other neurons more readily than normal.

Taken together, hyper-reactivity and hyperplasticity mean that minicolumns in VPA rats (and presumably in autistic humans too) have a higher than normal capacity for processing information. And this, say the Markrams, is autism’s fundamental problem.

Take sensory disturbance, for example. Excessive information processing in the microcircuits that handle incoming data from the senses leads to exaggerated perception, producing extremely intense images, sounds, smells and touch, the Markrams claim. Hyperactive microcircuits, meanwhile, could prove difficult to integrate into a whole, so perception would be highly fragmented. This sensory overload causes autistic kids to withdraw from the world, or pay excessive attention to small fragments of it. “It’s what anyone would do if they were embedded in a welter or cacophony of unpredictable events,” says autism researcher Matthew Belmonte of Cornell University, Ithaca, New York.

The hypothesis also provides an explanation for the three core deficits of ASD. Social problems, for example, are a direct consequence of children withdrawing from the world during critical developmental windows. Because the developing human brain requires repeated exposure to relevant stimuli at the right time to develop properly, early avoidance of social stimuli can have a devastating effect on a child’s social development. “They don’t learn because they don’t interact,” says Kamila Markram.

Similarly, children whose exposure to language during infancy is inadequate will have impaired language skills all their lives. When almost every sensation is overwhelming it’s hard to socialise at all, let alone speak.

Hyperplasticity, meanwhile, could account for repetitive behaviour and the compulsive desire for routine in people with ASD. Plasticity underlies learning and memory, so hyperplastic brains could be primed for what the Markrams call “hypermemory”. “They build very strong memories,” says Kamila Markram. “So strong that you establish a routine that you can’t undo: you are stuck on a track.”

At the same time, however, by locking them into specific narrow interests and compelling them to practise compulsively, hypermemory may be what drives some autistic people to develop savant skills. This appears to be how musical, artistic and mathematical savants develop their talents.

Unfortunately, if their focus is too narrow, savant-like skills can appear to be the exact opposite. “If your focus of attention becomes too local then you may become an expert on such a tiny system – the wheel of your toy car, say – that you end up with very little demonstrable knowledge about other, wider systems,” says Baron-Cohen.
Wired for fear

Another crucial element of the new hypothesis is that VPA rats also have hyperconnectivity and hyperplasticity in the amygdala, the almond-shaped brain structure where memories of fear are made and stored, which looms large in many theories of autism. VPA rats learn to avoid frightening situations more quickly than other rats, readily fear non-threatening stimuli, and are quick to generalise fear from one situation to another. They also have a much harder time learning that a once-scary situation is now safe (Neuropsychopharmacology, vol 33, p 901).

Assuming humans also have these changes in their amygdala, this could further explain some of the symptoms of autism. As a result of an overactive amygdala, says Kamila Markram, autistic people find the world “not only intense, but also aversive”. Ordinary situations can be terrifying and fear is easy to learn and hard to forget. This is another reason why autistic people prefer predictable, repetitive routines and can overreact, sometimes explosively, to change.

So far the intense world hypothesis is playing well with autism experts. “I really think it is spot on,” says Belmonte. “For some years the autism literature has needed a greater focus on the idea of autistic behaviour as a normal response to an abnormal perceptual and cognitive world.” Baron-Cohen too sees many positives. While he disagrees with some aspects of the idea, overall, he says: “The attraction of the research is to find basic differences between the autistic and typical brain, out of which higher cognitive differences such as in systemising may develop. In this view, the higher cognitive differences are secondary to these more basic sensory differences. This is a view I have a lot of sympathy with.”

It also rings true with autistic people. “When I was younger, the school bell was like a dentist’s drill hitting a nerve,” says Temple Grandin, an animal scientist at Colorado State University in Fort Collins well known for being autistic. “I think it’s difficult for people to imagine a reality where sounds hurt your ears and a fluorescent light is like a discotheque,” she says. The Markrams have also received a positive response from families affected by ASD. “It gives them comfort,” Kamila Markram says, “there are actually reasons why these children aren’t responding well.”

Some experts, however, are not convinced. The strongest critique comes from those who think the hypothesis extrapolates too much from the VPA rat. “[The Markrams are] extremely good on the neurophysiology… but we don’t yet know how to translate what the neurons are doing to what’s happening psychologically,” says neuropsychologist Chris Frith at University College London. “I think they made a leap too far.”

Keller, however, defends the use of animal models, noting that VPA causes the same anatomical and behavioural abnormalities in humans, monkeys and mice. “I see it not as a model, but as a recapitulation of the disease in other species,” he says.

These arguments aside, the intense world theory also has implications for the debate over the ultimate causes of autism. Although autism is highly heritable, genes alone are not enough to explain it; in pairs of identical twins where one twin has autism, the other is affected only 60 per cent of the time at most.

The VPA rat’s striking similarities to autism suggest that the condition might arise early in pregnancy when an as-yet unknown environmental insult combines with genetic vulnerability to damage the brainstem at a vital time. “What this study emphasises is not genetics but environment,” says Casanova. “It also emphasises the idea of a window of vulnerability. The timing of the insult is of great importance.”

This could also explain the wide range of the autistic spectrum, from severe impairment requiring 24-hour care to the near-normality of high-functioning Asperger’s. The later in the window exposure occurs, the less wide-ranging the attack on the fetal brainstem would be, reducing the subsequent damage as more regions would already have had time to develop unharmed.
Testing times

So how can the intense world idea be tested further? One way is to look for a correlation between sensory problems and the severity of ASD. If people with the worst oversensitivity – as measured by reactions to light, sound and touch – have the most incapacitating autism, that would offer support. And if intervening early in sensory problems mitigated the symptoms of autism this would also be evidence in favour.

Keller is collaborating on just such a study with researchers at Johns Hopkins University in Baltimore, Maryland, who have pioneered early detection in children as young as 6 months. Together they are looking at autistic children at the earliest possible stage to see whether reducing their sensory overload can help. Strategies include noise-reducing headphones and other ways of producing calmer, less stimulating environments.

These same measures already work for children who have endured severe early trauma and neglect, such as being raised in an understaffed or abusive orphanage. These children often have overactive amygdalas, heightened fear memories, are withdrawn and exhibit repetitive behaviours indistinguishable from autism.

The results of early intervention to help autistic children will be watched with interest, not least because one of the most striking features of the intense world hypothesis is that it casts almost everybody on the autistic spectrum as highly gifted. “Basically, our theory really says that most autistic people or people with Asperger’s are savants,” says Kamila Markram. “But this is buried under social withdrawal and fear of new environments. Their resistance to interaction and fear may obscure the hypercapability that they have. It may well turn out that successful treatments could expose truly capable and highly gifted individuals.”

Autism basics

The autistic spectrum disorder (ASD) includes classical autism (now known as autistic disorder), Asperger’s syndrome (also known as high-functioning autism) and a constellation of similar but somewhat ill-defined conditions including Rett’s syndrome, disintegrative disorder and pervasive developmental disorder-not otherwise specified (PDD-NOS).

Five leading theories of autism

Weak central coherence

Sees autism as a failure to integrate sensory information in a holistic or “gestalt” manner.

Executive function

Impairment of the brain’s frontal lobes causes loss of the top-down “executive” controls which build the big picture at the expense of minutiae.

Mind-blindness

An underactive amygdala – a brain structure central to the processing of emotional information, especially fear – leads to severe problems with empathy and theory of mind.

Extreme male brain

An excess of testosterone during early development magnifies typical male cognitive traits, such as systemising, at the expense of empathy, sociability and other more typically “female” thinking styles.

Intense world

The new kid on the block. Proposes that the root cause of autism is a supercharged brain (see main story).

Do supercharged brains give rise to autism?

Finally! A theory of autism that feels right!

I know that what holds me back socially is not ‘mind-blindness’ or ‘lack of empathy’ but my fear/shyness/stress response to other people. I have evolved several coping mechanisms to deal with this – the most primitive one is laughter. Since being very young, I giggle my way through sentences, even when there’s nothing to laugh at. This helps to relieve the stress response I feel when I interact with people, although it can make people misinterpret me, think I’m flirting with them, or think I’m completely crazy. I described in a previous post how the fear response in the amygdala is goverened by glutamate receptors. Autistics are thought to have brains bristling with glutamate receptors. This is a really good reason autistics should avoid MSG!

The other theories of autism listed above just don’t take into account what it feels like to be autistic or aspie. They are usually patronising and quite insulting and talk about autism in terms of brain damage and what is missing. Though the Markrams still resort to unfortunate language like ‘devastating’ to describe autism (a popular cliché that gets bandied about far too much), they at least take into account the increased brain size and neural processing power that autistics have. Here’s a link to the full text of the intense world hypothesis.

I don’t think they need to fall back on brain stem damage in the majority of autism cases. It just depends whether you were born or made autistic. I think the statistic quoted in the article of 60% autism concordance for twins is misleading – we’re actually talking about either twin just scraping either side of the diagnostic criteria. I’ve seen statistics of eighty or ninety percent in identical twins for more specific features of autism – and some of that mismatch can be explained by simple chaos theory. Things change and go in different directions as they grow. Everyone knows no pair of twins looks exactly alike. The same goes for their personalities.

The extra processing power, brain capacity, savant skills, and intelligence of autistics is usually painted as a meaningless quirk, something that results from the wider ‘brain damage’ in certain autistics. In actual fact it’s central to autism. I think some kids are just so autistic they can’t learn to use the big brains they’ve been gifted with because they can’t break through the fear, learn language, or deal with the sensory amplification.

I’ve been frustrated that the ‘theory of the mind’ (that autistics are ‘mind-blind’ to others and unable to empathise) seems to describe a condition that sounds completely alien to me, yet when I read the blogs of other auties and aspies, I see myself quite clearly. Sometimes doctors describe autistics as though they are emotionless automatons. This is far from the truth, especially as many autistics have parents or close relatives who have bipolar disorder. You can’t get more emotional than bipolar disorder. I feel things very deeply. A lack of empathy isn’t central to autism, it’s just a feature of the social withdrawal.

At last this is an attempt to understand autism from the autistic’s perspective instead of the perspective of the neurotypical observer. One could in fact accuse those neurotypical observers as being mind-blind themselves, for failing to empathise with the autistic and placing too great an emphasis on what are actually the secondary effects of the brain differences (lack of sociability, lack of empathy, lack of conformism, need for routine), instead of the primary effects (fear, stress, sensory amplification, pain, increased processing power).

In spite of the difficult sensory and emotional issues, there are so many positives to autism. That increased processing power creates great programmers and engineers, and even artists and writers (I’m sure Dean Koontz and Poppy Z Brite are at least half-aspie). I don’t think the modern world would actually function without aspies in the workforce acting as lynchpins and keystones in those highly specialised jobs no one else can do. I would argue that the autistic personality and brain are required by the modern age, and that many inventions and technological advances would not have occurred without the effort of individuals who have autistic tendencies.

Sometimes the sensory disturbances themselves can lead to great talent. A lot of musicians and composers have autistic traits. When music takes over your brain, your brain can learn the patterns in the music. My sister and I both have a perfect ear. We can distinguish tiny differences in pitch between notes. My sister  harnessed her heightened sensory perception of sound and became a musician who can pick up tunes and distinguish and name notes by ear.

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Written by alienrobotgirl

25 September, 2008 at 10:05 pm

Posted in Autism

Diagnosis creep

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This is one for the ‘autism epidemic’ crowd.

I watched Rain Man last week for the first time in years.

This is an extract from the Rain Man script:

Doctor: (To Charlie) In his case, he’s pretty well off. He’s very high-functioning. Most autistics can’t speak or communicate. (To Raymond) Do you know what ‘autistic’ is?
Raymond: Yeah.
Doctor: You know that word? Are you autistic?
Raymond: I don’t think so. (Pause) No. Definitely not.

If you watch Rain Man today you probably regard Raymond as suffering from ‘severe’ autism. Rain Man was released in 1988. When Rain Man was released, Raymond was regarded as unusually high functioning because he could talk.

These days anyone who has more IQ points than facebook friends is regarded as autistic. Well, not quite. But you get my point.

This is a phenomenon sometimes referred to as ‘diagnosis creep’. It happens a lot in medicine. Diagnosis criteria are revised and expanded all the time, funnelling in larger and larger segments of the population. Acceptable cholesterol levels and blood glucose levels have been revised downwards repeatedly during the last thirty years or so. Not so long ago anyone with a diagnosis of ‘manic depression’ was locked up in an asylum. Nowadays it’s almost trendy to be bipolar. ADHD and dyslexia have followed a similar pattern. When I was a child only the most severe cases were diagnosed – anyone else was just a poor learner.

Written by alienrobotgirl

22 April, 2008 at 3:19 pm

Posted in Autism

Autism: a moral panic

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When the Centers for Disease Control announced last year that an average of one out of 150 children had autism, it convinced many people that America was seeing an explosion of autism cases.

Before the 1990’s, the official estimates were one autistic child out of every 2,000 to 5,000 children. Several autism advocacy groups took that as proof that some environmental toxin, such as mercury preservative in vaccines, had caused a huge spike in the autism numbers.

But there are now intriguing indications that most if not all of the autism increase is the result of broadening the criteria for the diagnosis and identifying children with autism who would have been labeled with a different diagnosis in the past.

A 2006 study in the journal Pediatrics found, for instance, that the national increase in identified autism cases in elementary schoolchildren between 1984 and 2003 had been paralleled by a similar decrease in the number of children labeled as retarded or learning disabled.

Paul Shattuck of Washington University in St. Louis, the lead author of the study, wrote last year that “in 44 of 50 states, the increase in autism was completely offset by a decrease in the prevalence of children considered ‘cognitively disabled’ or ‘learning disabled.’ “

Some very outlandish claims have made about the supposed ‘rise’ in autism from many quarters – some have even sneaked their way into Wise Traditions, a publication from the Weston A. Price foundation that I used to respect.

As someone who is a fourth generation asperger (that’s a family history of roughly a century, long before anyone had invented the term), and a sociologist, I would define the media rhetoric surrounding the supposed ‘rise’ in autism as a moral panic – a form of mass hysteria. Examples of other moral panics include, gay sexuality, the millenium bug, foot and mouth disease, single mothers, immigrants ‘taking over’, youths (‘hoodies’) who hang out on the streets, and bird flu.

Some of the features of a moral panic include the demonisation of a subgroup within society and the emotive language used to describe the phenomena. The media usually lead and fuel moral panics with the use of unrepresentative and extreme portraits of the phenomenon in question, and the misuse of statistics. If you are autistic and reading this, you are probably as sick as I am to read offensive and bigoted descriptions of autism as ‘devastating’, ‘monstrous’, ‘robotic’, ‘destroying children’s and parent’s lives’ and ‘stealing children’s soul’s’.

In an interview this week, Dr. Shattuck said that because of changes in the definition of autism and how it is measured, it is impossible to know how much it may have increased from past years.

But his study certainly suggests that “diagnostic substitution” — labeling someone as autistic today who would have been labeled as retarded 30 years ago — is a substantial part of the picture.

Dr. Shattuck’s study isn’t the only one showing this trend.

In a 2004 study, Lisa Croen of the Kaiser Foundation Research Institute in California and her team found that the increase in children diagnosed with autism in that state between 1987 and 1994 was almost exactly paralleled by a decrease in those diagnosed with retardation.

In case you didn’t know, the Kaiser Foundation Research Institute is THE most trustworthy, independent, and thoughtful scientific institutions in existence. Kaiser operates independently of financial influences and makes highly critical scientific reviews and examinations of data based on extremely rigorous critera rarely employed by other scientists.

Nancy Minshew, the director of the University of Pittsburgh’s Center for Excellence in Autism Research, said last week, “I used to think there were more cases [than in past years], but I don’t think so any more.” She is now convinced that the higher numbers are “not an increase in the number of cases, but are an improvement in recognition.”

In past decades, she said, it was often hard to get doctors or schools to diagnose higher-functioning children as having autism. They were often labeled as having “behavior difficulties.”

Dr. Shattuck said other epidemiological studies have shown that the rate of severe autism has stayed steady at about one to two children per 1,000, so that the main part of the increase to an estimated six to seven children per 1,000 has come in the milder, higher-functioning forms of the disorder.

That points partly to the broader definition being used for what are called Autism Spectrum Disorders today, he said.

“When we talk about autism spectrum disorders,” he said, “we’re talking about kids who have very different symptoms. Some are severely retarded; some have high IQs; some have pathological shyness; others want to have contact but are socially awkward.”

In other words, the definition of autism has expanded to include asperger’s syndrome. Asperger’s syndrome was only added to the DSM-IV in 1994. At that point it became an official syndrome and millions of people who had previously been classified as normal were suddenly considered autistic. So when people talk about the ‘massive rise’ in autism since the early 1990’s, they are in fact talking about the ‘massive rise’ in asperger’s syndrome. With awareness comes diagnosis. A bit of a no-brainer really. Left Brain Right Brain has numerous good articles on bad statistics.

And when people say they don’t remember seeing so many autistic children when they were growing up, or ask where all the adults with autism are, there are two possible explanations, Dr. Minshew said.

One is that many autistic children in the past were never sent to school. In what she called the “Forrest Gump era, you didn’t even go to school, or you went to a totally separate school.”

Indeed they do. My aunt worked at a special school for many years until it was closed down. At the time it was closed under the misguided community integration policy, it was one of the few surviving special schools in Nottinghamshire. The children there received special therapies and had chill out rooms. I’ve no idea what happened to those children. You can’t put a child who rocks and headbangs, cannot speak, and yes, smears poo, into a mainstream classroom. At least, not unless you want them to be abused by their fellow students.

The other phenomenon was that some autistic children were labeled as schizophrenic, and many may have ended up in state hospitals or other institutions, she said.

There is even a kind of logic to that, Dr. Minshew said, because some of the hallmarks of schizophrenia — behaving oddly, a lack of facial expressions, poor eye contact, speaking in a monotone and using fewer gestures than normal — are “essentially the same” in both autism and schizophrenia.

David Mandell, an epidemiologist at the University of Pennsylvania medical school, recently surveyed the adult patients in Norristown State Hospital in Eastern Pennsylvania, nearly all of whom are labeled schizophrenic, and found that about 20 percent of them meet the behavioral criteria for being autistic.

Donna Williams was one of them. She was diagnosed autistic in adulthood, after a childhood where she was believed to be deaf, and labelled psychotic and disturbed. Neurologically and genetically speaking, autism and schizophrenia are not that far removed. One of the genes in common is a variant of Catechol-O-Methyltransferase, disproportionately found in schizophrenia, bipolar disorder, and autism.

While he believes misdiagnosis in the past explains a part of the increase in autism numbers, Dr. Mandell also believes the growth has been too great to be accounted for just by continuing genetic abnormalities.

“The increase is probably too fast to be genetics,” he said, “so there probably is something that is environmental, but there is nothing to suggest it’s the vaccines.” Studies raise questions about increase in autism cases

Let me see… what has changed about our diet since the early nineties? Well, schoolchildren have been eating an increasingly additive-heavy diet. During the same period the government has increasingly promoted the consumption of fresh fruits and vegetables, and these fruits and vegetables have increasingly been picked before they are ripe, and the varieties used have increasingly been bred for resistance to pests. All of these factors increase salicylate consumption. At the same time, calcium propionate started to be added to bread products and is now ubiquitous. Simultaneously big supermarkets took over the meat supply and began the mass vacuum-packing of meat. It is quite normal for meat to be three months old before it is eaten now – something that taxes even the average person’s resistance to amines. So amines and glutamates have increased too.

From my own perspective, I was raised on a very bland diet of cereal, bread, milk, fresh meat from the butcher’s, and potatoes. I refused to eat fruit except for the rare banana, or in the form of Ribena blackcurrant juice, and I wouldn’t eat most vegetables with the exception of cauliflower. I didn’t taste broccoli until I was perhaps eleven or twelve years old. This was around the time that mum and dad decided we should all eat more interesting and experimental foods. Like pizza and spaghetti bolognaise. Yes, you did read that right. Those were exotic foods to us. When I was thirteen years old we were all diagnosed with fibromyalgia. During the same period my ability to socialise declined to almost zero. I spent most of my teenage years as a voluntary mute.

Written by alienrobotgirl

6 February, 2008 at 10:39 pm

Posted in Autism

Tagged with ,

Eye contact in autistics

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Brain tests at UW-Madison suggest that autistic children shy from eye contact because they perceive even the most familiar face as an uncomfortable threat. […]

Tracking the correlation between eye movements and brain activity, the researchers found that in autistic subjects, the amygdala — an emotion center in the brain associated with negative feelings — lights up to an abnormal extent during a direct gaze upon a non-threatening face. Writing in the March 6 issue of the journal Nature Neuroscience, the scientists also report that because autistic children avert eye contact, the brain’s fusiform region, which is critical for face perception, is less active than it would be during a normally developing child’s stare. […]

Notably, the UW-Madison study overturns the existing notion that autistic children struggle to process faces because of a malfunction in the fusiform area. Rather, in autistic children the fusiform “is fundamentally normal” and shows only stunted activity because over-aroused amygdalas make autistic children want to look away, says senior author Richard Davidson, a UW-Madison psychiatry and psychology professor who has earned international recognition for his work on the neural underpinnings of emotion.

“Imagine walking through the world and interpreting every face that looks at you as a threat, even the face of your own mother,” Davidson adds. Scientists have in the past speculated that the amygdala – which has been implicated in certain anxiety and mood disorders – plays a role in autism, but the study directly supports that idea for the first time. Eye contact triggers threat signals in autistic children’s brains

I’m totally freaked out by the picture of the man’s face on this page by the way.

It appears to be glutamate receptors in the amygdala that govern fear response, something that ties in with the suspicion of abnormal glutamate function in autism and asperger’s.

I have had a serious, socially disabling inability to make eye contact for most of my life. I only became self-conscious of this during my teens and it was something that really frustrated me and I tried very hard to correct it. Although all I wanted to do was stare at the floor when people talked to me, I would wrestle with myself to try to behave normally and make eye contact. What I felt when I made direct eye contact with people was fear, almost pain. The level of fear ranged from intimidation up to actual stabs of terror. Most often when I had to speak to strangers I would physically tremble.

People find it rude when you don’t look at them when they are talking to you, and I was told off many times for not making eye contact – people assumed that I wasn’t paying attention. The coping mechanism I developed was to repeatedly make eye contact very briefly before looking away again, and to try to appear to be concentrating on what was said to me when I looked away with a ‘concentration frown’ expression. Apparently I wasn’t very good at this expression because people often asked me “what’s wrong?” – misinterpreting what I was trying to express as worry or anxiety. This trait of mine was interpreted as shyness by my family. Asperger’s wasn’t even recognised until 1994.

I’ve chipped away at this fear over the years. It was only in my mid to late twenties that I began to make real headway. I still find it very difficult to look people in the eye for more than a couple of seconds, and often I can only do this by unfocused my eyes and looking through them, smiling and creasing up my eyes in the hopes that this disguises my unfocused gaze. The only people I can genuinely look in the eye for more than a couple of seconds are my partner and my sister.

Written by alienrobotgirl

30 August, 2007 at 4:37 pm

Posted in Autism

Visual thinking

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When I was much younger, I assumed that everybody perceived the world the same way I did, that everybody thought in pictures. Early in my professional career I got into a heated verbal argument with an engineer at a meat-packing plant when I told him he was stupid. He had designed a piece of equipment that had obvious flaws to me. My visual thinking gives me the ability to ‘test-run’ in my head a piece of equipment I’ve designed, just like a virtual reality computer system. Mistakes can be found prior to construction when I do this. Now I realize his problem was not stupidity; it was a lack of visual thinking. It took me years to learn that the majority of people cannot do this, and that visualization skills in some people are almost nonexistent.

All minds of the autism spectrum are detail-oriented, but how they specialize varies. By questioning many people both on and off the spectrum, I have learned that there are three different types of specialized thinking:

1. Visual thinking – Thinking in Pictures, like mine
2. Music and Math thinking
3. Verbal logic thinking

Since autism is so variable, there may be mixtures of the different types. The importance of understanding these three ways of thinking comes into play when trying to teach children with ASDs. Strategies that build on the child’s area of strength and appeal to their thinking patterns will be most effective. This is most likely to become evident between the ages of five and eight. In children younger than five, it is often difficult to identify their strengths yet, unless savant skills are unfolding.

VISUAL THINKERS

These children often love art and building blocks, such as Legos. They get easily immersed in projects. Math concepts such as adding and subtracting need to be taught starting with concrete objects the child can touch. Drawing and other art skills should be encouraged. If a child only draws one thing, such as airplanes, encourage him to draw other related objects, such as the airport runways, or the hangers, or cars going to the airport. Broadening emerging skills helps the child to be more flexible in his thinking patterns. Keep in mind that verbal responses can take longer to form, as each request has to be translated from words to pictures before it can be processed, and then the response needs to be translated from pictures into words before it is spoken.

MUSIC AND MATH THINKERS

Patterns instead of pictures dominate the thinking processes of these children. Both music and math is a world of patterns, and children who think this way can have strong associative abilities. They like finding relationships between numbers or musical notes; some children may have savant-type calculation skills or be able to play a piece of music after hearing it just once. Musical talent often emerges without formal instruction. Many of these children can teach themselves if keyboards and other instruments are available.

VERBAL LOGIC THINKERS

These children love lists and numbers. Often they will memorize bus timetables and events in history. Interest areas often include history, geography, weather and sports statistics. Parents and teachers can use these interests and talents as motivation for learning less-interesting parts of academics. Some verbal logic thinkers are whizzes at learning many different foreign languages.

The thinking patterns of individuals with ASD are markedly different from the way in which ‘normal’ people think. Because of this, too much emphasis is placed on what they ‘can’t do.’ While impairments and challenges do exist, greater progress can be made teaching these individuals when parents and teachers work on building the child’s strengths and teach in a manner that is aligned with their basic pattern of thinking.
Dr Temple Grandin

I thought everyone thought visually. But then I would, I’m an aspie. I see diagrams and patterns and visualise how systems work in pictures in my head all the time. Often when I want to explain things, I want to draw a diagram. I am not a visual thinker to the same extent as Dr Grandin, as I do also use words in my head, more so as I have got older. As a wannabe author I have a very strong visual fantasy world, and it is the vision that comes first, followed by the linguistic description. When I try to understand chemistry the only way I can do it is by looking at the diagrams of chemicals and imagining how they would fit together. I am very good at reading maps. I can’t stand it when someone else is in control of the map. Often I think of things without using words, and sometimes it puzzles me that some people’s thinking seems to be constrained by the meanings of words. My dad once surprised me by telling me it was unusual to dream in colour with sound. I always dream that way. Is that unusual?

When I do maths I see numerals and patterns of dots in my head. When I do fractions I see slices of pie. This makes me very slow and bad at maths. I have always thought I am missing the ‘maths circuit’ because it doesn’t come out automatically. Numerous attempts to learn the times table have failed.

My dad was recently astounded by his IQ test results which are over 150. He is extraordinarily good at 3D/spacial visualisation. I’ve never actually broken down my IQ test results, though I suppose I should.

On the other hand my sister is a self-taught musician… in most instruments from guitar to piano to drums and even the sitar. I think she is a music thinker. I think she gets this from our paternal grandmother, who was a violinist and a pianist. So in my Dad and myself, it’s popped up as visual thinking, and in my sister it’s popped up as music thinking. Me? I try not to listen to music, because it tends to take over my brain.

I think I’m also a bit of a verbal logic thinker. When I was a teen I was a frightening statistic-hoarder but that skill diminished over time and I’ve always been sad that I’ve lost it. I have a tendency to try to deduce foreign languages and I have fair comprehension of a lot of foreign languages when I see them written down based on Latin/Greek/Germanic roots. By contrast my understanding of spoken foreign language is virtually zero. I also have the stereotypical interest in history and the weather. Yes I do know the bus timetable. Oh yeah, and I’m a writer.

I wonder how far the verbal logic thinking notion extends? I am good at logic per se and also spotting confounding variables. Most of my time I’m thinking “that’s not a valid conclusion because of X Y Z confounding variables. Observations A B C also indicate that the argument doesn’t fit. If we turn it on its head and point the causation in a different direction it might make more sense…” Except I don’t do it in words, in me it’s as automatic as feelings or knee jerks.

Written by alienrobotgirl

15 August, 2007 at 8:30 pm

Posted in Autism

People with moles age more slowly than others

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People who seem to stay younger for longer are also likely to have more moles, research released yesterday suggests.

A study of twins found a striking correlation between high numbers of moles and a biological marker for slow ageing.

As a result, people with a lot of moles might be expected to live longer than those who have very few, despite facing a greater risk of skin cancer.

Dr Veronique Bataille, from the Twin Research Unit at King’s College London, who led the study said: “The results are very exciting as they show, for the first time, that moley people who have a slightly increased risk of melanoma [skin cancer] may, on the other hand, have the benefit of a reduced rate of ageing.

“This could imply susceptibility to fewer age-related diseases such as heart disease or osteoporosis, for example. Further studies are needed.”

Moles appear in childhood and tend to vanish from middle age onwards. People with white skin average about 30 moles, although some may have as many as 400.

The reason for these differences is unknown, as is the function of moles. Previous research has shown that up to 60 per cent of susceptibility to moles is inherited.

Because moles disappear with age Dr Bataille’s team looked at their relationship with telomere length, a good biological indicator of an individual’s rate of ageing.

Telomeres are protective bundles of DNA found at the end of chromosomes in all cells. As cells divide, the telomeres shorten until a point where the chromosomes become unstable. The cell may then stop dividing or die.

The scientists compared more than 1,800 twins and found that participants with high numbers of moles – more than 100 – had longer telomeres than those with fewer than 25 moles.

The difference between the two groups was equivalent to six to seven years of normal ageing estimated by looking at the average rate of telomere length loss per year.

People with a lot of moles appeared to have longer telomeres and to keep their moles for longer. Those with shorter telomeres had fewer moles and tended to lose them more quickly with age.

Prof Tim Spector, head of the Twin Research Unit and co-author of the study published in the journal Cancer Epidemiology Biomarkers & Prevention, said: “We now plan to look in more detail at the genes which influence the numbers of moles and to see whether they may also slow down the ageing process.” The Telegraph. See also a similar story on the BBC.

There’s also supposed to be a correlation between people with autism and aspergers looking younger than their years (ironically in spite of the extra [shock! horror!] oxidative stress caused by low glutathione levels). I wonder if there is also a correlation between autistics and moles, or whether there are two separate phenomena going on?

All the women I know who are about my age have wrinkles around their eyes, yet I have none. Sometimes I find myself staring across restaurant tables thinking; surely you are too young to have wrinkles? I have aspergers*, and plenty of moles from my Dad’s side of the family. The aspie side.

Or it could be the sheer perfection of my diet, which is low in fruits and vegetables and high in cholesterol, salt, fat and sugar? Grin.

Right. As I’m going through one of my weird energetic manic phases at the moment (induced by an extremely low carbohydrate diet combined with drinking espresso and eating cheese), I’m off to drink cocktails and do dancing.

* I’m treating it as a fact now.

Written by alienrobotgirl

11 August, 2007 at 5:31 pm

Posted in Autism