Table of ContentsDescription of Dyslexia DisorderConclusionReferences:Description of Dyslexia DisorderDyslexia is an inherited “neurodevelopmental disorder” that is recognized by slow, incorrect word recognition and inadequate reading/spelling skills despite ability to learn (Peterson & Pennington, 2012). Dyslexia can be acquired, when a reading disorder occurs in people who had previously learned to read but lost this ability due to severe brain damage (Peterson and Pennington, 2012). The most common type, however, appears to be developmental dyslexia, a reading disorder that often occurs in a child who has not initially learned to read normally (Cotheart & Jackson, 1998). According to the International Classification of Diseases (as cited in Silvia, Ueki, Oliveira, Boggio, & Macedo, 2016), developmental dyslexia is classified as a specific reading disorder and is a well-known learning disorder. Individuals with developmental dyslexia have a specific impairment in acquiring reading skills, leading them to have difficulty recognizing and spelling words accurately and effortlessly (Silvia et al., 2016). Many children with developmental dyslexia exhibit these impairments despite having intelligence, satisfactory instruction, and the absence of obvious neurological or sensory impairment (Snowling, 2008). Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”? Get an original essay A study by Stein (2001) found that 5-10% of children will fail to read to adequate standards, which regardless of their supportive environment. Dyslexia can be identified when individuals begin to demonstrate slow and influential reading, often making errors, such as mixing up letters and syllables, incorrect word recognition (Ramus, Rosen, Dakin, Day, Castellote, White and Frith, 2003). Dyslexia can be identified in children through various reading tests to assess where their reading abilities are compared to other children of the same age (Castles. A., personal communication, 2018). However, it is possible that some children did not have the chance to learn to read. They are removed from classification by providing them with a supportive environment to learn to read and then comparing their reading skills after a short period to see if they are up to par (Castles. A., personal communication, 2018). Reading involves many processes and therefore different types of dyslexia depending on which reading sub-skill has not been developed (Castles. A., personal communication, 2018). There are five main types of dyslexia. Surface dyslexia occurs when individuals have difficulty acquiring whole words (Castles. A., personal communication, 2018). Phonological dyslexia occurs in individuals who have poor knowledge of letter sound rules (Ramus et al., 2003). People with hyperlexia have accuracy in reading aloud simple words and nonwords normal for their age, but their single-word reading comprehension is insufficient (Castles. A., personal communication, 2018 ). Letter identification occurs when individual letters cannot be identified and letter position dyslexia occurs when letters are accurately identified but their position in the word is not (Castles. A., personal communication, 2018). Case StudyPatient RE (Butterworth & Campbell, 1985)Patient RE is a well-educated university graduate, who has rare difficulty reading and spellingnonwords (Butterworth & Campbell, 1985). R. E's developmental dyslexia had been overlooked as a child, and she went on to graduate from college without her reading disabilities going unnoticed. Due to her ongoing illnesses, she was unable to attend school and was homeschooled by her mother most of her life (Butterworth & Campbell, 1985). According to his mother, RE spoke well from a young age. However, upon entering school, his reading did not progress. Patient RE was first noticed by Butterworth and Campbell (1985) when they observed that RE could not read a new word out loud until she heard someone else say it . Butterworth and Campbell (1985) then carried out an examination of the patient's RE, studying parts of reading and writing, to determine exactly where the impairment had occurred. The study states that “the neuropsychological brain organization of RE is normal”. (Butterworth and Campbell, 1985, p.440). RE has been observed to perform above average on standard tests of reading, spelling, and cognitive abilities. However, it does not perform well on tasks that require knowledge of phonemic structure, such as “reading nonwords, judging rhymes, and matching homophones” (Butterworth & Campbell, 1985, p. 446). Butterworth and Campbell (1985, p. 442) found that RE can read aloud, correctly and without hesitation, unusual and irregularly spelled words such as "placebo and idyll." In this test, of the 45 misspelled words, RE was able to accurately read aloud and provide correct definitions for 33 of them. Based on this, RE can be classified as a good reader. Second, RE was asked to read aloud words from a list of 30 three-letter nonwords. From these words, she was unable to provide the correct pronunciation of nine of them and her reading of each word was very slow and hesitant (Butterworth & Campbell, 1985). RE was then asked to read a list of longer nonwords, in which out of 20 she was only able to read aloud correctly three. She said she found the task very tiring and gave up several times (Butterworth and Campbell, 1985). This study suggests that RE has a particular deficit in the ability to recall and manipulate phonemic information, essential for pronouncing most non-word stimuli (Butterworth & Campbell, 1985). The study concludes that RE exhibits deficits related to phonological decoding deficiencies, shown by his low scores on phonological awareness tasks (Butterworth and Campbell, 1985). Cognitive theoryPhonological theory suggests that people with dyslexia have a specific deficit in the “storage or retrieval and representation of speech sounds,” called phonemes (Peterson & Pennington, 2012, p.4). According to the phonological theory of dyslexia, individuals lack the ability to listen to and manipulate letter sounds, which is crucial for various oral language tasks such as non-word reading (Ramus et al. , 2003). Theory suggests that it is the phonological coding process that determines accurate and fluent reading and word recognition, therefore a deficit in this process leads to poor performance in phonemic awareness tasks (Silvia et al., 2016) . To read an alphabetic system, it is necessary to learn “graphemophoneme correspondence” which is the relationship between letters and the sound they create (Ramus, 2001, p.2). The theory suggests that individuals with dyslexia have difficulty representing these sounds in their brain and recalling them, resulting in an impairment inthe organization of phoneme-grapheme mappings in dyslexic brains (Ramus, 2001). For example, to read nonwords accurately, the reader must be able to recall the sounds, map them to letters, and assemble a pronunciation for that word. However, people with dyslexia do not have this ability (Wimmer, 1996). dyslexia, inability to read non-words. This is because reading without words depends more on phonological processes than reading with words (Ramus, 2001). The finding that there are dyslexic patients, like patient RE, who can read words accurately but not nonwords supports the phonological theory of dyslexia. Observations of patients like RE, who have low scores on phonological awareness tasks and who have difficulty retaining speech in short-term memory, support the theory that dyslexic individuals have a phonological deficit (Butterworth and Campbell , 1985). The finding that RE has unusual difficulty reading and spelling nonwords indicates that she must have a deficit in the ability to store and recall phonemes (Butterworth & Campbell, 1985). Many other individual and group case studies have also found evidence supporting the phonological theory of dyslexia. Stothard, Snowling & Hulme (1996) studied the case of LF, a normal child of average intelligence, who experienced significant difficulties in phonological tasks. It was observed that although LF's reading and spelling skills were proficient, his nonword reading was impaired (Stothard et al., 1996). They proposed that LF had severe phonological impairments, illustrated by his poor performance on phonological tasks. Snowling, Stackhouse, and Rack (1996) studied seven developmental dyslexics who exhibited nonword reading problems and numerous spelling errors. Based on their poor performance on tests of phonological awareness and short-term memory, Snowling et al. (1986) also concluded that all subjects studied had phonological deficits. These studies suggest that subjects lack the phonological representations necessary to learn to read fluently and therefore provide evidence that supports phonological theory (Butterworth and Campbell, 1985; Stothard et al., 1996; Snowling et al. 1986). ). However, a study by Stein (2001) suggests that dyslexics have difficulty learning to read due to an impairment of the magnocellular pathways involved in vision and hearing. This study, however, has limitations such as measuring visual attention using linguistic stimuli and has been subject to major criticism for its inability to reproduce the results (Stein, 2001; Ramus, 2001).ConclusionIn conclusion , previous studies of dyslexic individuals such as RE and LF, provide evidence that dyslexia is caused by the inability to map representations of speech sounds onto letters (Butterworth & Campbell, 1985; Stothard et al., 1996). Most of the existing literature provides evidence and support for the phonological theory of dyslexia, while accepting that there is possible interaction with other neurocognitive factors (Butterworth & Campbell, 1985; Stothard et al., 1996; Snowling et al., 1986; However, the current literature contains its limitations. Many studies have been conducted on a small sample size, without replication and due to age and gender bias (Ramus et al., 2003; Carroll and Snowling, 2004). Recent studies suggest that a single phonological deficit is not enough to cause dyslexia, as there appear to be few rare cases of children.1996.0004