Developmental Dyslexia Essay

Developmental dyslexia was defined in 1968 by the World Federation of Neurology as a disorder that illustrates difficulty in learning to read despite typical intelligence and education. However, intelligence is no longer considered essential for a dyslexia diagnosis. Morgan (1896) first recognized this condition when he examined a 14-year old boy for his vision because his parents thought that his inability of learning to read was due to vision impairments. He termed this condition as congenital word blindness because he found the boy’s vision to be intact but printed words were found to have no significance to him. According to the Diagnostic and Statistical Manual of Mental Disorders, an individual should be diagnosed with dyslexia if their …show more content…
According to the dual route model, irregular words are read via the lexicon whereas nonwords are read via the non-lexical route, suggesting that they are read via grapheme to phoneme correspondences (Coltheart, Rastle, Perry, Langdon and Ziegler, 2001). Some researchers believe that developmental dyslexia is caused by a phonological problem, which occurs at the phonological awareness level, phonological processing or the phonological recoding. Hence, in a review, Rack, Snowling and Olson (1992) found that children with reading disabilities exhibit significantly lower phonological processing. They argued that nonword reading was accurate to measure phonological processing and deficits in children. Therefore, Rack et al (1992) support the account of a single reading deficit as they argue that dyslexia is caused by problems with phonological processing and subtypes of developmental dyslexia do not exist. Furthermore, Snowling (1980) found similar findings despite matching the control group on reading levels. Findings indicate that dyslexics display difficulty with phonological processing, which proves that there is a clear difficulty in reading