Dyslexia

Dyslexia is said to be a neurological disorderwith biochemicaland geneticmarkers. The popular definition for many years was that it was a disability in which a person's perception is reversed or that a dyslexic sees things backwards and, therefore may read or write backwards. However this is no longer believed to be true. Now the popular conception of dyslexia is asserted to be readingor writingability is significantly low. One approach is to compare their ability to that which would be predicted by his or her general level of intelligence, but some would say that it is not certain that intelligence should be a predictor of reading or writing ability; and also that the causes, effects and treatments of reading disabilities may be similar for all levels 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), but this is disputed. Other contradictions are also said to exist among those diagnosed with dyslexia seeming to point to the fact that dyslexia is a highly complicated disorder. Neuroscientific, psychological, and educationalresearch is still needed to understand the scope of dyslexia.

There are alternative definitions of dyslexia and much debate over the definition of dyslexia and how best to treat it. The British Psychological Societydoes not describe it as a mental condition or neurological disorder:

"It is very common to try and deal with dyslexia as if it is a mental condition, with one test and one feature but that is just not the case" ^{[{{fullurl:Template:FULLPAGENAME}}#endnote_BPS2004Court]}.

The BPS does not link dyslexia with intelligence in their definition:

"Dyslexia is evident when accurate fluent word reading and or spelling develops incompletely or with great difficulty. This focuses on literacy learning at the 'word level' and implies that the problem is severe and persistent despite appropriate learning opportunity"

"Learning difficulties of a Dyslexic nature are not defined by general ability as measured by IQ, but by cognitive processes under-pinning basic literacy. Learners representing a wide range of general ability and IQ can have dyslexic problems".^{[{{fullurl:Template:FULLPAGENAME}}#endnote_BPS2004Court]}

The term was coined in 1884 by R. Berlin ^{[{{fullurl:Template:FULLPAGENAME}}#endnote_BerlinR1884]}. People are diagnosed as dyslexic when their reading problems cannot be explained by a lack of intellectual ability, inadequate instruction, or sensory problems such as poor eyesight. Because reading is a complex mental process, dyslexia has many potential causes. From a neurophysiological perspective, dyslexia can be diagnosed by close inspection of the morphology of the brain, usually upon autopsy. Dyslexia is also associated with phonologicaldifficulties, such as enunciation.

Debate and Controversy

There is much debate and indeed controversy over the definition, cause and treatment of dyslexia. Here is an attempt to summarize some of the viewpoints expressed on the subject. Other parts of this article will discuss the correctness or otherwise of these viewpoints.

Viewpoint 1: 'Dyslexia is simply reading difficulty, and is also easily explained and cured'

This point of view is relatively uncommon among the general public and dyslexics themselves, but is said to be very popular among the scientific community involved with education - see the #Referencesat the bottom on this article.

Cause: This point of view contends that:

1. Dyslexia is primarily caused by insufficient quality of education, both in the home (such as letting young children watch TV instead of reading nursery rhymes to them) and in the classroom (such as teachers using whole languageand other novel teaching schemes to the exclusion of traditional Phonics).
2. There may be some genetic or hereditary factors or even nutritional factors that may modify a child's desire or ability to read, but they do not cause a problem which can't be fixed with a little early extra traditional education.
3. Reading and writing are fundamental basic processes that almost every human is perfectly capable of, along with speech and walking. :# Some say there may be a very small group (<1%) of people who really do have severe difficulties with reading that can't be solved with traditional education, but this is not relevant to the diagnosis and treatment of the ~10% of people described as dyslexic today.

Treatment: This point of view contends that:

1. Traditional teaching methods are the only proven methods for teaching reading.
2. There is no scientific evidence that novel methods such as coloured glasses or physical coordination exercises have any effect.
3. While some children may require more help than others, including one-to-one tuition, they will be totally cured (as opposed to having learned to live with the condition).
4. Dyslexia amounts to nothing more than a delay in the learning process caused by a lack of quality education in the home and classroom.

Definition This point of view contends that the definition should be:

1. The term dyslexia, if it is to be of any use, should simply to be defined as those who currently have difficulty reading, regardless of its speculated cause.
2. The threshold separating dyslexics from non-dyslexics is entirely arbitrary.

Viewpoint 2: 'Dyslexia IS a neurological/mental disorder which affects about 10%'

This is the popular point of view, at least among the general public, teachers, and dyslexics themselves, however it's now coming under sustained attack. Its primary contention is that there is more to dyslexia than Viewpoint 1 states. i.e. It's not just bad teaching, and it's inborn to about 10% of the population.

Cause: This point of view contends that:

1. There are a number of factors including genetics, but there is more research to be done.
2. Dyslexia is inevitable from birth and is not related to the quality of traditional education given.
3. Dyslexia cannot be cured, only treated.
4. Those who are successfully treated are still in some sense 'different' than non-dyslexics who are at the same reading level. Perhaps in terms of brain structure or brain activity.
5. Dyslexic children are different from non-dyslexics even if they are at the same reading level as them.

Treatment: This point of view contends that:

1. Coloured glasses, exercising the eyes, physical coordination exercises can treat dyslexia.
2. The testimony of a person who is dyslexic is to be believed. This includes self-analysis of brain function, or discussing the success or otherwise of treatments.

Definition: This point of view contends that the definition should be:

1. Dyslexia is a distinct mental condition which affects reading and writing ability. It's defined in such as way as to include about 10% of the population.

Viewpoint 3: 'The term dyslexia is essentially useless and should now be made obsolete to avoid confusion'

Definition: This point of view contends that:

1. The current popular definition used by the general public ('Dyslexia IS a neurological/mental disorder') is entirely incorrect and useless. The definition used by the scientific community is totally different and therefore the term just breeds confusion. There may be a group (perhaps less than 1% of the population, not 10%) who have reading difficulties untreatable by traditional education, but we should not use the term 'dyslexia' for their condition, because it will cause confusion. New terms should be created for any verifiable conditions.

Variations and related disorders

Dyslexia is a learning disorder. Its underlying cause may be neurological in nature, but from there, the systems involved play out into visual, language, etc. FMRI(Functional Magnetic Resonance Imaging) has been used to demonstrate differences in the dyslexic brain patterns, but much research still needs to be done to apply this information.

In addition to the typical forms of dyslexia, there are numerous related disorders:

• Auditory Processing Disorderis the cause of the phonological problems that many dyslexics experience, and causes problems in the auditory memory or working memory and this can cause some memory issues.

• Semantic dyslexia- a form of dyslexia characterized by an inability to properly attach words to their meanings in reading and/or in speech.
• Scotopic sensitivity syndrome- a form of dyslexia which makes it very difficult for a person to read black text on white paper, particularly when the paper is slightly shiny.
• Dyspraxia- a neurological disorder characterised by a marked difficulty in carrying out routine tasks involving balance, fine-motor control, and kinesthetic coordination.
• Verbal Dyspraxia- a neurological disorder characterised by marked difficulty in the use of speech sounds, which is the result of an immaturity in the speech production area of the brain.
• Dysgraphia- a neurological disorder characterised by distorted and incorrect writing.
• Dyscalculia- a neurological disorder characterised by a problem with learning fundamentals and one or more of the basic numerical skills. Often people with this disorder can understand very complex mathematical concepts and principles but have difficulty processing formulas and even basic addition and subtraction.

Facts and statistics

Between 5 and 15 percent of the populationcan be diagnosedas suffering from various degrees of dyslexia. As previously mentioned, dyslexia can be substantially compensated for with proper therapy, training and equipment.

Most researchers agree that there is a fairly even gender balance amongst dyslexics, and that the fact that it is reported more in males is because of selection factors and bias.

Dyslexia's main manifestation is a difficulty in developing reading skills in elementary schoolchildren. Those difficulties result from reduced ability to associate visual symbols with verbal sounds. While motivational factors must also be reviewed in assessing poor performance, dyslexia is considered to be an inborn trait and rarely arises from environmental factors after the brain has matured beyond its especially plastic condition during infancy.

Some have disagreed with these findings, however, and believe that while dyslexia may sometimes be inborn, it is often attributable to lack of phonicstraining when learning to read, and also attributed to the preponderance of the whole languagesystem.

Physiology and treatment

Only traditional educational remedial techniques have any record of improving the reading ability of those diagnosed with dyslexia ^{[{{fullurl:Template:FULLPAGENAME}}#endnote_AAP1998]}. There is no evidence that coloured lenses, any visual training, or similar proposed treatments are of any use. Anecdotal reports of success can be explained by other factors.

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. 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 dyslexic symptoms from some of the underlying causes. It is claimed that many of the underlying causes of dyslexia are of a genetic nature and that there are no cures, only strategies to work around the causes of a persons dyslexia, however these two claims are disputed.

It had been believed that keeping a child active, perhaps by giving them housework, or performing physical exercises, would help with dyslexia. However, this is false (Wilsher 2002 - Dyslexia, Volume 8, Number 2, April/June 2002, pp. 116-117(2)). There is no scientific evidence in support of this theory.

One hypothesis for some of the symptoms of an underlying cause of dyslexia is a lack of overall short-term memory. Typically a dyslexic will not remember a person's name, and will suffer an undue amount of difficulty in transcribing (for example) a phone number. These problems could be attributed to the short term memory having to run the coping strategies needed to overcome a range of issues caused by the underlying causes of dyslexia.

Researchers studying the brains of dyslexics have found that during reading tasks, dyslexics show reduced activity in the left inferiorparietal cortex. It is anecdotallyclaimed that 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. Commonly dyslexics show 10 times more brain activity when reading. Sometimes, depending of the type and extent, also writing, listening and speaking. However, increased brain activity is not necessarily a sign of better processing. Conversely, some dyslexics may show a natural dislike of reading and, in consequence, compensate by developing unique verbalcommunication skills, inter-personal expertise, and leadership skills - however these possible outcomes are the same for people who have no difficulty reading. Different people adopt different strategies for living with the same affliction. It is said that this may be because there may be different underlying causes of their dyslexia.

In 1979, anatomical differences in the brain of a young dyslexic were documented. Albert Galaburdaof Harvard Medical Schoolnoticed that the language centerin a dyslexic brain showed microscopic flaws known as ectopiasand microgyria. Both affect the normal six-layer structure of the cortex. An ectopia is a collection of neuronsthat have pushed up from lower cortical layersinto the outermost one. A microgyrus is an area of cortex that includes only four layers instead of six. However, this may well have nothing to do with dyslexia - it was only a study of one brain, not a scientically controlled study of a large number of brains. Also, changes in brain structure do not tell us anything about the root cause or possible treatments - it could be genetic, or the brain structure could simply be a result of a combination of insufficient education along with the actions of the dyslexic, causing the brain to develop in a particular way. The causes and effects of dyslexia are difficult to disentangle.

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.

Several geneticregions on chromosomes1 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 brainand enhance or reduce a particular component of human mental capacity.

Some studies have concluded that speakers of languages whose orthography has a strong correspondence between letter and sound (e.g. Koreanand Italian) have a much lower incidence of dyslexia than speakers of languages where the letter is less closely linked to the sound (e.g. Englishand French).[1]

Whether 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 limitations on the overall intellectual function. At the same time, dyslexia shows that the brain exhibits a strong ability to compensate for its acquired limitations, and intense training can often result in miraculous turnabouts.

Characteristics

Most dyslexics will exhibit about 10 of the following traits and behaviors. These characteristics can vary from day-to-day or minute-to-minute. The most consistent thing about dyslexics is their inconsistency. Symptoms increase dramatically with confusion, time pressure, emotional stress, or poor health. This may vary according to which of the suggested underlying causes of dyslexia affect the individual dyslexic.

The following list of traits and behaviours is very long (35 at the moment) and they are all very general so it's quite likely that most of the population, dyslexic or not, would complain of 10 of the following traits and behaviours so this list should be treated with caution.

General

• Appears to be bright, seemingly highly intelligent, and articulate but unable to read, write, or spell at grade level.
• Isn't "behind enough" or "bad enough" to be helped in the school setting.
• Feels dumb; has poor self-esteem; hides or covers up weaknesses with ingenious compensatory strategies; easily frustrated and emotional about school reading or testing.
• Perhaps talented in either art, drama, music, sports, mechanics, story-telling, sales, business, designing, building, or engineering.
• Seems to "Zone out" or daydream often; gets lost easily or loses track of time.
• Difficulty sustaining attention; seems "hyper" or "daydreamer."
• Learns best through hands-on experience, demonstrations, experimentation, observation, and visual aids.

Vision, reading, and spelling

There is no scientific evidence that a relationship exists between reading failure and perceptual ability or that visual training provides effective treatment. [2].

Hearing and speech

• Has extended hearing; hears things not said or apparent to others; easily distracted by sounds.
• Difficulty putting thoughts into words; speaks in halting phrases; leaves sentences incomplete; stutters under stress; mispronounces long words, or transposes phrases, words, and syllables when speaking.

Writing and motor skills

• Trouble with writing or copying; pencil grip is unusual; handwriting varies or is illegible.
• Clumsy, uncoordinated, poor at ball or team sports; difficulties with fine and/or gross motor skills and tasks; prone to motion-sickness.
• Can be ambidextrous, and often confuses left/right, over/under.

Maths and time management

• Has difficulty telling time, managing time, learning sequenced information or tasks, or being on time.
• Shows dependence on finger counting and other tricks when doing math; knows answers, but can't do it on paper.
• Can count, but has difficulty counting objects and dealing with money.
• Can do arithmetic, but fails word problems; when doing maths must see the big picture before the detail.

Memory and cognition

• Excellent long-term memory for experiences, locations, and faces.
• Poor memory for sequences, facts and information that have not been experienced.
• Thinks primarily with images and feeling, not sounds or words (little internal dialogue)

Behavior, health, development and personality

• Extremely disorderly or compulsively orderly.
• Can be class clown, trouble-maker, or too quiet.
• Had unusually early or late developmental stages (talking, crawling, walking, tying shoes).
• Prone to ear infections; sensitive to foods, additives, and chemical products.
• Can be an extra deep or light sleeper; bedwetting beyond appropriate age.
• Unusually high or low tolerance for pain.
• Strong sense of justice; emotionally sensitive; strives for perfection.

Public support

In the United States, Canadaand in the United Kingdom, some people say that there is a lack of adequate support and a general lack of interest in the learning disabilities of children in public schools. This has recently led to legal action by private parties against public schools in the United States and state schools in the United Kingdom.

Some charitable organizations like the Scottish RiteFoundation have undertaken the task of testing for dyslexia and making training classes and materials available for teachers and students. [3][4][5]

In English law, the failure of schools to diagnose and provide remedial help for dyslexia became grounds for personal injury litigation in 1999 following a House of Lordsdecision in the case of Pamela Phelps. Students with dyslexia in Higher Education may receive support funded via the Disabled Students Allowance. Support can take the form of IT equipment (software and hardware) as well as personal assistance, also known as non-medical helper support. Dyslexic students will also be entitled to special provision in examinations such as additional time to allow them to read and comprehend exam questions.

The British Disability Discrimination Actalso covers dyslexia.

"In some cases, people have 'coping strategies' which cease to work in certain circumstances (for example, where someone who stuttersor has dyslexia is placed under stress). If it is possible that a person's ability to manage the effects of the impairment will break down so that these effects will sometimes occur, this possibility must be taken into account when assessing the effects of the impairment." — Paragraph A8, Guidance to the Definitions of Disability

Many doctors and teachers diagnose students with Attention Deficit Disorderrather than dyslexia. Of all the conditions that can mimic, mask or co-exist with ADD, dyslexia is probably the most well known. It is also one of the most misunderstood. Dyslexia is a learning disability that affects 17-20% of school age children according to the Department of Health, Education and Welfare. Like ADD, the dyslexic mind functions differently than others. Dyslexic children, like ADD children, tend to be above average intelligence, if not gifted. But they have specific difficulties with words. They have difficulty recalling words, even words they are familiar with. They also have difficulty with sequencing. Letters and syllables can become inverted (like "aminal") as can entire words. ("Come here over.") The child may have trouble distinguishing between the letters "b," "d," "q" and "p."

Bibliography

• de Lacoste-Utamsing, C., and Holloway, R., Sexual Dimorphism in the Human Corpus Callosum, Science, Vol 216, 1982.
• Dennis, M., Impaired Sensory and Motor Differentiation with CC Agenesis: A Lack of Callosal Inhibition during Ontogeny? Neuropsychologia, vol 14 p. 455-469, 1976.
• Duffy, F., Denkla, M., Bartels, P., and Sandini, G., Dyslexia: Regional Differences in Brain Electrical Activity by Topographic Mapping, Annals of Neurology, vol 7 #5, 1980
• Ettlinger, G., Blakemore, C. B., Milner, A. D., and Milner J., Agenesis of the Corpus Callosum: A behavioral Investigation, Brain, vol 75, 1972.
• Ferriss, G. S., and Dorsen, M., Agenesis of the Corpus Callosum: Neuropsychological Studies, Cortex, vol2, #2, 1975.
• Gazzaniga, M. S., Cognitive and Neurologic Aspects of Hemispheric Disconnection in the Human Brain, Discussions in Neurosciences, vol 4, #4, FESN, 1978.
• Gazzaniga, M., Consistency and Diversity in Brain Organization, Annals of the New York Academy of Sciences, vol 299, Ps 415-424, 1977.
• Gladstone, M., and Best, C. T., Developmental Dyslexia: The Potential Role of Interhemispheric Collaboration in Reading Acquisition, Hemispheric Function and Collaboration in the Child, Ed., Catherine Best, Academic Press 1983.
• Gross, K., Rothenberg, S., Schottenfield, S., and Drake, C., Duration Thresholds for Letter Identification in Left and Right Visual Fields for Normal and Reading-Disabled Children, Neuropsvchologia, vol 6, 1978.
• Gross-Glenn, K., and Rothenberg, S., Evidence for Deficit in Interhemispheric Transfer of Information in Dyslexic Boys, International Journal of Neuroscience, vol 24, 1984.
• Haggerty, R., and Stamm, J. S., Dichotic Auditory Fusion Levels in Children with Learning-Disabilities, Neuropsychologia, vol 16, 3, 1978.
• Harris, A. J., Lateral Dominance and Reading Disability, Journal of Learning Disabilities, vol 12, #5 1979.
• Horowitz, B., Rumsey, J.M. and Donohue, B.C., Functional Connectivity of the Angular Gyrus in Normal Reading and Dyslexia, Proceedings of the National Academy of Sciences, vol 95, July 21, 1998
• Hynd, G.W. et al., Dyslexia and Corpus Callosum Morphology, Archives of Neurology, vol 52, Jan., 1995
• Snowling, M.J. (2000). Dyslexia. Blackwell Publishing: ISBN 0631205748

See also

• Picture thinking
• Double deficit
• List of people with dyslexia
• Alexia (disorder)

External links

Associations and organizations

• Auditory Processing Disorder in the UK
• The International Dyslexia Association (IDA)
• Useful Website for Parents of Dyslexics
• Dyslexia Council UK
• British Dyslexia Association
• Canadian Dyslexia Association
• Society for the Scientific Studies of Reading
• Asociación Dislexia y Familia
• Asociación de Dislexia
• Recording for the Blind & Dyslexic

Tools and other helpful information

• Assistive Technology - Ayudas Técnicas
• Portal da Dislexia
• Dyslexia International - Tools and Technologies (DITT)
• Kurzweil Educational Systems
• Bookshare.org
• Recording for the Blind & Dyslexic
• National Library Service for the Blind and Physically Handicapped
• About Dyslexia
• Dyslexia Screening at the University of Nottingham
• "Is it possible to be dyslexic in Chinese?" at Straight Dope
• "The Dyslexia Guide" - A to Z and FAQ info

References

1. ^  British Psychological Society report on a British High Court judgement regarding the definition of dyslexia.
2. ^  Learning Disabilities, Dyslexia, and Vision: A Subject Review A report from American Academy Of Pediatrics reporting the complete lack of evidence for a link between visual problems and learning difficulties. Essentially, coloured lenses and other visual gimmicks and exercises should be avoided according to this report.
3. ^  Berlin, R. (1884). Uber Dyslexie. Archiv fur Psychiatrie, 15, 276-278.da:Ordblindhed

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It uses material from the http://en.wikipedia.org/wiki/Dyslexia Wikipedia article Dyslexia.