Definition of Dyslexia
Dyslexia is one of the conditions of the broader spectrum of learning difficulties. There are specific learning difficulties that are different from what could be defined as “Dyslexia.” Specific learning difficulties are a set of conditions that emanate from the brains processing coupled with the individuals other processing abilities. These difficulties have been labeled as dyscalculia, dyspraxia, dysgraphia and so on. It is stated that there are fifteen such learning disabilities. Dyslexia forms a part of this classification but is slightly different from the others. There is a co-morbidity that can be noticed between these specific learning difficulties. There are many symptoms that overlap and co exist. The difficulty in pinpointing the actual and simple definition of dyslexia arises from this overlapping of symptoms. (Reid, 2003)
Though the term “Dyslexia” is used in the denotation of “specific learning difficulties” It is argued earlier that “dyslexia” is one variant. The definition of the problem thus can, be simply stated as a great abnormal problem in learning to read, write and spell. But these difficulties could also be experienced by children who are not necessarily dyslexic. There is further difficulty if for example autism where such symptoms may be prolific and the patient can also suffer from dyslexia and may not have any links between the problems although they appear similar. (Riddick, 1996)
The Medilexicons medical dictionary defines “Dyslexia” as a person with impaired reading ability that is very much below that persons level of intelligence. This assumes some factors like normal vision, letter recognition, and recognition of the meaning of pictures and objects. (Kraft, 2010) The general definition thus is that it is a disorder in children undergoing class room study has difficulty in getting language skills that is reading writing and spelling. The definition of the World Federation of Neurology that was adopted by the National Institute of Health in 1968 was — it was a disturbance expressed in the process of learning that led to disability in reading and writing in persons with otherwise normal intelligence. (Lundberg; Tonnessen; Austad, 1999) The problem is that here the childs actual performance is compared to the expected performance that would have resulted from the exercise. (Nicolson; Fawcett, 2008)
In analyzing for dyslexia the important feature that is to be noted is the fact that there must be persistent reading difficulties — but experiments have shown that some students in the lower grades who had learning difficulties have gone on to master their difficulties in the higher grades, and such students are not properly dyslexic. The problem with the traditional definition is that it tried to tie up the symptoms merely with intellectual infirmities. The reading disability and has been later proved is in no way connected with the intellectual problems of the individual. The acceptable definition therefore is one that can keep away this bias. The American definition proposed is that “Dyslexia is one of the several learning disabilities and is a language-based disorder of physical (bodily) origin that can be seen in the difficulty of single word encoding, and decoding, with insufficient phonological abilities.” (Hoien; Lundberg, 2000) That definition does not create a blanket that includes all the disorders but pinpoints the issues of Dyslexia.
2. Signs and Symptoms of Dyslexia
Merely the inability to read and comprehend thus does not form a symptom. Over a century ago the symptoms were studied in Germany and later by the British Paediatrist Morgan. In the U.S., Samuel Orton studied dyslexia for the symptoms and structure and was able to classify the disease. (Hoien; Lundberg, 2000) There are thus certain observable phenomena that appear leading to permanent difficulties in learning to read that could be a symptom of developmental dyslexia. These symptoms also could be of much other specific reading disability. One such symptom is “reversals.” There is observed confusion among the patients when presented with the mirror images of alphabets that look alike — like B. And d. These are static reversals and in another case the kinetic reversals where the inability to distinguish the order of words like “girl” and gril.
The error and shortcoming is common with most children but with the confirmed dyslexic it can be observed that the frequency is very high and beyond the common time for the child to rectify these errors, and these errors are more often caused by visual perceptual deficit. It could also have a linguistic origin and visual processing deficits leading to reading disability. (Willows; Kruk; Corcos, 1993)
Another symptom is that the reader though can understand the word or letter may mislabel or mispronounce them while reading. Other general symptoms include drowsiness; dilated pupils along with problems of expression and learning and retaining words. The dyslexic child may read the word “bad” as if it were “dab” reversing the letters may also be a feature of the Dyslexics. (Kraft, 2010) There are neurological symptoms that underlie the condition and in studies with five-year-old children it has been shown that there are many substrates of the disease, and each abnormality in the reading paradigm relate to different regions of the brain and its morbidity. So for each individual case the symptoms can vary. (Nicolson; Fawcett, 2008) Thus there could be difficulty with language. The people may have difficulty with sounds and words. They also cannot recall important or explaining main ideas of what they read or in proper pronouncing of words, and may be impervious to learning of nuances like, synonyms, rhymes, opposites and idioms. (Kraft, 2010) Persons with more of these symptoms may be diagnosed for dyslexia.
4. Causes of Dyslexia
Many theories have been put forth for the causes of this disease. The major argument so far is that it is a genetic impairment. This impairment cause the change in the way the brain deals with the information and how it is processed. This problem is observed to be passed on in families. The problem is centered on the process of phonological processing impairment that causes the dyslexic to be impaired in learning and writing. (Kraft, 2010) There are two types of the disease, one is acquired and the second developmental. The acquired type can be identified in the case where a normal reader and writer suddenly lose most of these abilities mostly due to pathological conditions including a brain injury. The second developmental dyslexia begins from birth and children have difficulty in reading and writing from the beginning. Most dyslexia falls into this category. Mostly it is seen to be dictated by the genes, and other conditions like lead poisoning, head injury in childhood. Genetic basis of dyslexia is found to be the basic cause and can run in families. (Hultquist, 2006)
The reasons for the problem could be biological, and more so, on the basis of the background of the patient. Biological reasons are more and numerous with genetics, brain damage and the brains inability to transfer or store information being the chief condition. (Nicolson; Fawcett, 2008) There could be cognitive impairment too. There are difficulties in the processing of sensory information that is passed on from the eye to the brain causing disruptions in visual perceptions. The second problem occurs with the mango system that goes on to process the details and colors and symbols that could associate with sounds and phonetics. Likewise it also could be a result of the deficit of the M-system. (Lundberg; Tonnessen; Austad, 1999)
Therefore the dyslexic persons brain functions in a different way from the rest of the people and some diagnosis could be made with Magnetic Resonance Imaging — MRI scans which will show the activity levels in all three regions of the brain much lower in people with dyslexia that is a symptom of phonological processing. (Kraft, 2010) Being a genetic condition the family history is.