The term’dyslexia’ was introduced in 1884 by the German ophthalmologists R Berlin. He coint it from Greek words’dys’ meaning ill or difficult and ‘lexis’meaning word. The problem was first described in 1896 by Dr. W Pringle, Morgan in England. He wrote about a bright and intelligent boy quick at games and no way inferior to others of his age. His great difficulty has been and now his ability to learn to read.
According to Medilexicons medical dictionary , dyslexia is impaired reading ability with a competence level below that expected on the basis of the person ‘s level of intelligence and the presence of normal vision , letter recognition and meaning of the pictures and object.
Dyslexia reflects a problem within the language system in the brain ( Syawiz 2003). There appear to be a ‘glitch ‘
In the neural wiring when it first lay down during the embryonic development, but this miswiring is confined to the specific neural system used for reading. Neurons are found in unusual places in the brain, and they are not neatly ordered as in non- Dyslexic brains.
In addition to unique brain architecture and usual wiring, functional studies of MRI have shown that persons with dislexia do not use the same part of the brain when reading as other person . Regular readers consistently use their same part of the brain when they read. Persons with dislexia do not use that part of the brain, and there appears to be no consistent part used among Dyslexic readers or the most efficient part of their brain is not used.
In dyslexia, the eyes and ears are working properly but the lower center of the brain scramble the images or sounds before they reach higher (more intelligent) centers of the brain. These causes confusion as well as frustration for the learner.
Dyslexia is a word reading problem due to differences in the brain that makes learning letter sounds difficult. Without adequate Letter sound knowledge, recognising words in print is slow and inaccurate . Thus dyslexia is a difference in the parts of the brain, Which process language . It is known that the brains of Dyslexic are wired differently than normal human brain, and thus process language less efficiently.
Incidence of Dyslexia is equal in sexes. Boys are more likely to act out as a result of having a reading difficultly. But girls are more likely to try to hide their difficulty becoming quiet and reserved. There boys are 1 1/2-3 times more likely come up with Dyslexia than girls.
Structural differences in brain of Dyslexics
The brain is made up of two types of materials, Gray matter and white matter. Gray matter is what we See when we look at brain and is mostly composed of nerve cells. Its primary function is processing information . White matter is found within the parts of the brain, is composed of connective fibers covered in myelin, the coating disingned to facilitate communication between nerves cells. White matter is primarily responsible for information transfer around the brain.
Booth and Burman (2001) found that persons with Dyslexia have less gray matter in the left parieto-temporal area than non Dyslexic individuals. This could lead to problems processing the sound structure of language (phonological awareness)
Many people with Dyslexia also have less white matter in this same area than average readers. This could lessen the ability or efficiency of the regions of the brain to communicate with one another.