Different Brains,. Different Learners. The Challenged Reader: Dyslexia. Instructor. Amy A L L E N. Student. Mia S P A N U. WHAT IS DYSLEXIA?.
The term dyslexia, first used in 1887, is derived from the Greek dys, which means difficult and lexicos which means pertaining to words.
IDEA defines Dyslexia as “a disorder in one or more of basic psychological processes involved in using language, spoken or written, which may manifest itself in an imperfect ability to listen, speak, read, write, spell, or do mathematical calculation… The term doesn’t include children who have learning problems which are primarily the result of visual, hearing, or motor handicaps, of mental retardation, of emotional disturbance, or of environmental, cultural or economic disadvantage” (Sullivan Spafford &Grosser, 1996).
Subtypes (Sullivan Spafford & Grosser, 1996):
1. visual-dysphonetic type
2. auditory-linguistic type
3. mixed type ( with symptomology consistent with the first types combined)
There are no consistent statistics regarding the percentage of individuals identified specifically as dyslexic because very often the term learning disability is used interchangeably with Dyslexia, Severe Reading Disorder (SRD) and Reading Disability (RD) (U.S. Department of Education, 1995, Schnaiberg, 1994, Brewster Clark & Kellogg Uhry, 1995).
The research requested by the U,S. Dept. of Education in 1995, indicated the percentage of 5.25% learning disabled students (of a total of 10.25% of disabled students who were served in American schools) At least half of these students (2.625%) would be classified as dyslexic.
If a parent is dyslexic, the child’s risk of developing the disorder is up to 8 times higher than the risk for a child without a family history in dyslexia.
5 to 12% of the school-aged population may be dyslexic
Dyslexia occurs close to equally in both sexes even some literature suggests that dyslexic boys outnumber dyslexic girls. The excess of identified dyslexic male children over females has been explained by a bias in the classroom referral system.
Dyslexia affects 10% of schoolchildren in the United States.
20% of children are born with varying degrees of Dyslexia.
Most students with dyslexia do not receive help until the 3rd grade.
Up to 80% of students with dyslexia who start receiving special services in 3rd grade will have the reading problem for the rest of their lives.
Heredity – Researchers have suspected that dyslexia is carried on human chromosomes, which determine and transmit hereditary characteristics. The new studies indicate Chromosome 6 as a source of dyslexia and estimate the risk of a dyslexic parent having a dyslexia child (Schnaiberg, L., 1994).
Auditory-Processing Deficits- Based on evidence, it has been suggested that dyslexia could result from pathology in the primary auditory cortex in the left hemisphere (Cocace, A.& McFarland, D. J., 1998). Dyslexic children with auditory-processing deficits are less able to pay attention and follow oral directions and they are easily distracted. Their inability to integrate auditory information and to make connection between phonemes and graphemes results in poor reading skills.
Phonological Awareness Problems is the metacognitive understanding that spoken language is made up of a series of sounds that have a sequential order. There is evidence that range of difficulties attributed to dyslexia may stem from phonological core deficit. According to Stanovich’s research ( 1988) dyslexic children’s failure to decode words is caused by phonological processing problems, which leads to deficits in reading comprehension, vocabulary development and even IO through lack of access to print experience
Visual System Dysfunction and Visual Memory Problems- Because of visual perception deficiencies the dyslexic children are not able to obtain meaning from the print. Magnetic resonance Imaging (MRI) data indicate a relation between dyslexia and a deficit in visual-motion processing (Eden et al., 1996).
Scotopic Sensitivity- Five % of dyslexics have difficulties seeing black-white contrast and painful sensitivity to light
Abnormal Neural Activity – PET scans reveal less activation of the left posterior and temporal areas of the dyslexics’ brain. Increased reading skill for dyslexic was correlated with greater reliance on the right hemispheric systems (Marshall, 2003).
Environmental factors – lack of individual and family reading experiences
BEHAVIOR/ACHIEVMENT? (cont’d )
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U. S. Department of Education (1995). Sixteenth annual report to Congress on the implementation of the individuals wit disabilities Education Act. Washiongton DC: U.S. Government Printing Office