Dyslexia

Dyslexia is a neurological disorder with biochemical and genetic markers. In its most common and apparent form, it is a disability in which a person's reading and/or writing ability is significantly lower than that which would be predicted by his or her general level of intelligence. However, as has been discovered only in the last decade, individuals may read and write perfectly and still have dyslexia (see "characteristics" below).

Physiology and treatment

Even a few weeks of intense phonological training (often involving breaking down and rearranging sounds to produce different words) can help noticeably improve reading skills. Unlike in normal adults, phonological training shows an increase in the activity in the right temporoparietal cortex.

Related Topics:
Phonological training - Temporoparietal cortex

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This part of the brain works in spatial tasks and may be the main compensatory structure in phonological training. This is the sister region of the left temporoparietal cortex responsible for visual motion processing which is underactive in many dyslexics. The earlier the phonological regimen is taken on, the better the overall result. Advanced brain scans could identify children at risk of dyslexia before they can even read, although it is thought that simple tests of balance could do the same. It has also been shown that early diagnosis and treatment can almost completely eliminate the symptoms of dyslexia.

Related Topics:
Spatial tasks - Motion processing

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The most important thing that can be done for the child is to make sure the child is kept active. You can do this by giving them simple jobs to do around the home such as cleaning the house. This helps improve their concentration and their motivational skills.

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One hypothesis for some of the symptoms of dyslexia is a lack of overall short-term memory. Typically a dyslexic will not remember your name, and will suffer an undue amount of difficulty in transcribing (for example) a phone number. These problems could be attributed to difficulty in laying down short-term memories.

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It is not that uncommon for dyslexics who have trained themselves to cope with their affliction, to develop uncannily efficient visual memories which aid in reading and comprehending large quantities of information much faster than is typical. Adversely, some dyslexics may show a natural dislike of reading and, in consequence, compensate by developing unique verbal communication skills, inter-personal expertise, and leadership skills. Different people adopt different strategies for living with the same affliction.

Related Topics:
Verbal - Communication skills

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A popular hypothesis for the reading difficulties experienced by dyslexics is strabismus, which is difficulty in bringing both eyes into focus on the same point. Such problems explain why dyslexics often confuse the sequence of written letters or numbers, as the end of the word is literally being seen first by one eye, then the beginning of the word is seen by the other eye. Studies in which young children are taught reading skills while wearing an eyepatch have shown very promising results. This is based upon the theory that, because children benefit more from learning to read than being confocal, the former should take precedence over the latter.

Related Topics:
Strabismus - Eyepatch

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In 1979, anatomical differences in the brain of a young dyslexic were documented. Albert Galaburda of Harvard Medical School noticed that language centers in dyslexic brains showed microscopic flaws known as ectopias and microgyria. Both affect the normal six-layer structure of the cortex. An ectopia is a collection of neurons that have pushed up from lower cortical layers into the outermost one. A microgyrus is an area of cortex that includes only four layers instead of six.

Related Topics:
1979 - Albert Galaburda - Harvard Medical School - Language center - Ectopia - Microgyria - Cortex - Neuron - Cortical layers

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These flaws affect connectivity and functionality of the cortex in critical areas related to sound and visual processing. These and similar structural abnormalities may be the basis of the inevitable and hard to overcome difficulty in reading.

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Several genetic regions on chromosomes 1 and 6 have been found that might be linked to dyslexia. In all likelihood, dyslexia is a conglomeration of disorders that all affect similar and associated areas of the cortex. With time, science is likely to identify and classify all individual suborders with benefits to our understanding of how low-level genetic flaws can affect the wiring of the brain and enhance or reduce a particular component of human mental capacity.

Related Topics:
Genetic - Chromosome - Brain

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Some studies have concluded that speakers of languages whose orthography has a strong correspondence between letter and sound (e.g. Korean and Italian) have a much lower incidence of dyslexia than speakers of languages where the letter is less closely linked to the sound (e.g. English and French). (Source: http://www-tech.mit.edu/V121/N12/shorts2_12.12w.html )

Related Topics:
Korean - Italian - English - French

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Whether today's models of dyslexia are correct or not, the main lesson of dyslexia is that minor genetic changes affecting the layering of the cortex in a minor area of the brain may impose inborn limitations on the overall intellectual function. At the same time, dyslexia shows that the brain exhibits a strong ability to compensate for its inborn or acquired limitations, and intense training can often result in miraculous turnabouts.

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