Teaching Dyslexic Students
The term dyslexia comes from Greek, and means difficulty with words (McClure, 2007, p. 86). A neurobiological disorder, it can vary in severity, and fluctuate over time, but can impact reading, writing, communication skills, and capacity to decode. Although it is not, however, related to intelligence or effort, it can be very challenging for students with dyslexia to succeed in school tasks without appropriate assistance and teaching methods. This article briefly describes dyslexia and describes details of some of the existing theories about its causes. It also includes a section of summaries from various sites specifically about how to teach dyslexic students.
Keywords Auditory Processing Disorder; Decoding; Dyslexia; Learning Disability; Multi-Sensory Teaching; Phonological Awareness; Phonological Deficit; Visual Attention Span; Visual Theory
What is Dyslexia?
The term dyslexia comes from the Greek language, and means, literally, difficulty with words (McClure, 2007, p. 86). A neurobiological disorder, it can vary in severity, and fluctuate over time, but can impact reading, writing, communication skills, and capacity to decode. Although it is not related to intelligence or effort, it can be very challenging for students with dyslexia to succeed in school tasks without appropriate assistance and teaching methods.
Dyslexia Teacher (2007) provides the following guidelines for identifying dyslexic students, noting that if a student seems intelligent and is otherwise not having difficulty understanding, indicators of dyslexia may include:
• Confusion over the direction letters face (b/d, p/9, p/q);
• Difficulties with left and right;
• Difficulties with keeping organized;
• Difficulties with spelling;
• Difficulties with directions (e.g. East and west);
• Missing out words when (Dyslexia Teacher, "Information About Dyslexia," 2007).
GoPhonics (2007) adds the following clues:
• Difficulty remembering the names of the letters of the alphabet
• Difficulty remembering the sounds of the letters
• Writing right to left -- mirror writing
• Reading words backwards (tap - pat)
• Scrambling letters in reading or writing (gril - girl)
• Substituting words for the written word (rat - mouse, truck - van, house - home) (GoPhonics, "Identifying and Teaching," 2007).
Ahissar (2007) explains: "Dyslexia is a persistent difficulty in acquiring adequate reading skills, in spite of normal education and general intelligence. Its prevalence is estimated as 5-10% of the population" (p. 458).
Types of Dyslexia
In a book summarizing conference proceedings on dyslexia, Blachman (2007) discusses the range of theories of potential causes and types of dyslexia, including:
• Naming speed deficit,
• Phonological dyslexia,
• Surface dyslexia,
• General auditory deficit,
• Differences in speech perception, and
• Deficits in temporal processing, among others.
Dinsmore and Isaacson (1986) describe differences between the auditory-linguistic and visual-spatial forms of dyslexia perception challenges:
Auditory-linguistic dyslexia is characterized by an inability to distinguish phonemic (or smallest) units of speech and a subsequent inability to learn the relationships between the visual appearances and sounds of letters and words. Deficits are evidenced in auditory discrimination, auditory sequencing, auditory focus, and auditory affective (emotional) perception. This disturbance is thought to be the most common cause of a developmental reading disorder (Mattis et al., 1975). Visual-spatial dyslexia is a less common cause of a developmental reading disorder. Students with visual-spatial dyslexia appear to have normal language development but are unable to learn the spatial and visual requirements necessary for acquiring reading skills. Deficits are evidenced in visual discrimination, visual sequencing, visual figure ground discrimination, visual depth perception, and visual affective perception (Dinsmore & Isaacson, 1986, par. 3).
Theories on the Causes of Dyslexia
Shaywitz and Shaywitz (2007) suggest a neurobiological basis for dyslexia, noting that "a strong consensus now supports the phonological theory, which recognizes that speech is natural, while reading is acquired and must be taught" (p. 20). This is aligned with theories that suggest that although speech has been part of the human experience for eons, reading is relatively new, and therefore the decoding process required for reading may be less developed in the brain, and is, in any case, different from the process required to speak and understand spoken words.
Various studies and data cited by Shaywitz & Shaywitz (2007) "show that children with dyslexia exhibit a failure of the left-hemisphere posterior brain system" (p. 20). Specifically, "Disruption or significant underactivation of posterior neural systems in dyslexia, especially disruption of the word form area, has been termed the "neural signature" of dyslexia" (p. 20).
Further, they suggest there is converging evidence indicating that over time, dyslexic readers come to rely on a memory-based system-so that instead of learning to sound out words, as skilled readers do, they instead rely on memorizing printed words to read. The brain systems used by good readers tends be the same areas of the brain used by readers using sound-based systems of word identification.
Shaywitz and Shaywitz (2007) go on to recommend that "the provision of an evidence-based reading intervention at an early age improves reading accuracy and facilitates the development of those neural systems that underlie skilled reading" (p. 21). Not only did struggling readers exposed to the specific intervention they suggested improve their reading skills, they also appeared to increase activity in the neural systems related to reading that are used by skilled readers.
Visual Attention Span Deficit
Some researchers suggests that phonological deficit is not the only explanation for dyslexia. Bosse, Tainturier, & Valdois (2007) suggest a multifaceted set of issues are engaged in dyslexia, "Both recent empirical data and theoretical accounts suggest that a VA [visual attention] span deficit might contribute to developmental dyslexia, independently of a phonological disorder" (Abstract).
They looked at two large samples of children from France and Britain, matching them to children of the same chronological age who had not experienced challenges in reading. They found in the French study that visual attention deficits could account for at least as much variance in reading performance as phonological skills issues did. The British study reinforced the findings, and added evidence that this finding held even after controlling for other factors such as IQ, verbal fluency, letter identification, vocabulary skills and phoneme...
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