History of Dyslexia
Dyslexia was initially termed by W. Pringle Morgan as ‘congenital word blindness’ in a medical literature in 1886. The phrase was however coined by German ophthalmologist named R. Berlin where dys is a Greek word referring to ‘difficult’ and lexus referring to ‘word’. Berlin applied the name to refer to particular difficulty in reading rather than due to visual interference.
Later, James Hinshelwood implied dyslexia to be ‘congenital word blindness.’ He also detailed the condition in his 1917 monograph where he referred to the condition as “congenital deficiency of the visual memory of words” (Gilman, 2007 p.593). From his observation, the condition was more prevalent in males as compared to females although recent research has proven otherwise.
In the cases described, there were lesions that were characterized by similar traits and concluded that the condition was a result of faulty development, leading to a declined processes of left angular as well as supramarginal gyri. Today, this has been asserted by current research which implicates the condition to the temporoparietal region.
Additionally, the neurologist Samuel Orton examined children with difficulties to read, write or speak. He improved the idea of developmental reading disorder into “a graded series including all degrees of severity of the handicap” (Gilman, 2007 p.594).
Orton appreciated the presence of comorbid developmental disorders such as speech delay, dysgraphia, repetitive language, stuttering, as well as difficulties with motor coordination. Besides, he described strephosymbolia or syllable reversals like confusing the word saw and was or d and b. he attributed strephosymbolia to deficiency in unilateral left hemisphere cerebral control for language rather than the traditional visual perceptual disorder.
From current research, individuals with the condition apply extra bilateral cortex when reading as compared to normal ones (Richards, 1999).
Definition of Dyslexia
Dyslexia is defined as a “developmental disorder of the neurological system that results in a relatively selective impairment of an individual’s ability to learn to red. It is described as an unexpected difficulty in learning to red in an individual who otherwise possesses the intelligence, motivation and schooling considered necessary for accurate and fluent reading “ (Gilman p. 593).
It is a learning disability, which is marked by difficulties in reading since the brain is unable to effectively recognize as well as process particular symbols. An individual’s fluency and comprehensiveness is affected such that they have hardships while reading and spelling. Their reading standard is lower but varies with individuals.
It could result from brain injury in adulthood or what is referred to as dementia. Some of the individual with dyslexia have a genetic predisposition and the condition is linked to particular genes, which predispose them. Dyslexia is managed by identifying the learning problems and teaching methods and learning conditions are changed so as to improve the symptoms that are associated with dyslexia (Leaner & Kline, 2006).
It is also referred to as Developmental Reading Disorder (DRD) that occurs as a result of difficulties in interpretation of language. Students with such a condition have normal intelligence and are able to understand complex tasks.
Individuals with dyslexia could experience difficulties in phonology, pronunciation, and rhyming words which are essential in reading skills hence are unable to understand particular sentences.
Dyslexia could have an impact on various functions such as visual and auditory where in the former there are difficulties with numbers and letters that could be reversed as well as difficulties in writing symbols sequentially. The latter is marked by difficulties with sounds where they are perceived incorrectly (Leaner & Kline, 2006).
Prevalence of dyslexia in school aged children is approximately 5 to 17 percent with differences in the sample population studied as well as criteria applied to diagnose. Prevalence is thought to be same irrespective of gender. From longitudinal studies, the condition traits shows difficulties even with improvement of reading skills.
Compensatory physiological processes persist in adults who have had previous reading impairment. There are also environmental aspects like type and quantity of reading that has an effect on the results of individuals with dyslexia.
Specific language impairment (SLI) has been linked to dyslexia where in cohort of children 77 percent scored less on tests involving single word reading while 98 percent scored less on tests involving reading comprehension.
Children with dyslexia are implicated with SLD in math and written expression although the highly notable cormobid is attention deficit hyperactivity disorder (ADHD). Significantly, 20 to 25 percent of children with dyslexia have ADHD while 10-50 percent of children with ADHD have dyslexia (Gilman, 2007).
Specific and systematic strategies could effectively manage the condition. Etiology and prevalence of the condition is implicated to people with particular genetic disorders like neurofibromatosis as well as klinefelter’s syndrome.
Besides, it is prevalent in children with previous medical histories like prematurity, in-utero exposure to drugs, hydrocephalus, congenital illnesses as well as early neurological disorders like neonatal stroke. All the same, people with dyslexia possess none of the risk factors. It is also supposed to be genetic and those with the history of the condition are supposedly a 23-65 percent likelihood of having a child with dyslexia.
However, 27 to 49 percent of children with dyslexia notably have a parent with the condition. Dyslexia prevalence in siblings of children with the condition is 40 percent having 84 to 100 percent concordance in monozygotic twins.
All the same, genetic processes of the heritability are indicated as heterogeneous and complicated. Currently, research has indicated occurrence of genes liked with chromosomes 1, 2, 3, 6, 7, 15 as well as 18. (Gilman, 2007)
Causes of Dyslexia
Dyslexia could be caused by brain trauma in the part that regulates reading as well as writing but the condition is rare and this type is called trauma dyslexia. Injuries to the nervous system, which is meant to facilitate communication within the brain, could cause dyslexia. An injury could have resulted due to fever and concussion such that the brain fails to receive signals appropriately.
Additionally, another type is primary dyslexia that emanates from dysfunction or harm on the cerebral cortex which never modify with age (Richards, 1999). Students with this form of dyslexia discontinues with schooling due to learning difficulties. This form of dyslexia is genetic and occurs more in males as compared to females. Finally, another form of dyslexia is termed as secondary dyslexia.
It is also referred as developmental dyslexia and emanates from abnormalities in hormonal growth in early fetal development. It however improves with age and occurs more in boys. Of importance, the Cerebella theory maintains that an impaired cerebellum could lead to dyslexia.
The cerebrum facilitates motor regulation in speech expression. The theory infers that expression difficulties could lead to phonological processing difficulties, which are implicated with dyslexia. Cerebellum also affects the automatisation of leant actions that involves learning and reading (Swarbrick & Marshall, 2004).
Another theory implicates dyslexia with problems in language processing referred to as phonological model. It asserts that the condition emanates from problems failure to break words into language units referred to phonemes e.g. ‘Cat’ has 3 phonemes named kuh, aah & tuh (Goldish, 2001).
Additionally, poor hearing could cause children with dyslexia to have difficulties in sounding words. This could be attributed to hearing impairment in childhood.
Characteristics of Dyslexia
There are other learning disabilities linked with dyslexia which are associated with neurological causes. To start with, dysgraphia is one such condition that depicts itself mainly through typing or writing. It also sometimes affects the coordination of eyes and hands orientation in undertaking tasks like tying knots or undertaking repetitive activities.
Dysgraphia in individuals with dyslexia is caused by a number of factors as a result of difficulties with writing letters with ease, finger-motor order impairment, organizational and intricate complexity as well as impaired visual word structure that impair visual picture retrieval needed in wording and spelling.
Additionally, Dyscalculia is another neurological impairment marked by having issues with fundamental sense of numerals and quantity hence problems in solving mathematics. However, they comprehend complex math although they experience problems in retrieval of fundamental facts that involves adding and subtracting. Attention Deficit Disorder is yet another condition notable in dyslexia.
This is however yet to be established scientifically. Finally, Cluttering is notable in individual with dyslexia. It is impairment of speech fluency that regulates speech pace and rhythms hence affecting speech clearness (Swarbrick & Marshall, 2004).
Teaching Strategies of Dyslexia
Phonemic awareness should be prioritized in managing symptoms of dyslexia. One word has to be taught while disintegrating it into its component phonemes. Phoneme or grapheme correspondence, follows where students with dyslexia are given letters and are shown the way to integrate them into one syllable word. The students are then shown how to use the six syllables, which are present in English language.
On becoming aware of every syllable they are presented with, they are able to recognize the sound associated with the vowel. Besides, on hearing a vowel sound, students are able to spell it in the correct way. The student is subsequently trained on probability and set of laws in accordance to the language taught.
Finally, the student is guided on roots, affixes and morphology, for them to enrich their vocabulary and comprehension in spelling strange words (Hall et al., 1998).
To teach these concepts, various strategies have to be employed. To start with, simultaneous multisensory directives are essential for individuals with dyslexia when they apply their entire senses in learning since they have enhanced potential in storage and retrieval of information. The student could see a letter, name, sound and write it.
In addition, strong directives followed by sufficient practice would help students with dyslexia to improve their learning skills. The instructions should be direct and explicit since students with dyslexia have difficulties with written information and must be taught explicitly about the rules on written language each at a time, up to the point they become conversant with them to read and spell in order to get into the next rule (Hall et al., 1998).
Another strategy should involve being systematic and cumulative since the students have difficulties with written language. Therefore, they have to be initiated with a solid base in teaching logic of language each at a time followed by practice, to fluently spell and read where they have to be reminded every time. This should be done logically from the beginning to the end.
Significantly, the teaching should be synthetic as well as analytic in recognizing each letter/sound and add them to give a word (synthesis). Besides, they should be analytic in the sense that they could split a long word into various parts.
Finally, diagnostic teaching is essential for teachers to assess the student’ potential to perceive as well as apply regulations without blindly memorizing a pattern and incase there are difficulties, they have to be re-taught (Hall et al., 1998).
Accommodations for students with dyslexia
Oral testing where tests have to be read to individuals with dyslexia while they respond orally. Besides, untimed tests help them to enhance their performance. When they are timed and pressured, they fail to do well. They also consume much time in reading questions and composing answers in order to write them down.
Teachers should therefore aim at minimizing spelling errors by carrying out spelling tests in tutoring class rather than that of the classroom. They should not oblige these students on loud oral reading in class. When it’s needed entirely, students should be given prior notice and the texts they are supposed to read for them to practice.
They should also have less homework since they take more time to complete it as compared to other students. They should be graded by content and not penalized on handwriting or spelling since it would be unfair for them.
Teachers should recognize dictated work and avoid the students with dyslexia from copying work. In addition, they could be given alternative assignments, which are not written e.g. video presentations and debates. Besides, essay tests have to be minimized and multiple choice questions could be included (Hall et al., 1998).
References
Gilman, S. (2007). Neurobiology of Disease. London: Academic Press.
Goldish, M. (2001). Everything You Need to Know about Dyslexia. New York: The Rosen Publishing Group.
Hall, S., Vail, P. and Lyon, R. (1998). Sharing the latest Research results with those who need to know. Bright Solutions for Dyslexia, Inc. Web.
Leaner, J. & Kline, F. (2006). Learning Disabilities and Related Disorders.10th ed. Boston: Houghton Mifflin.
Richards, R. G. (1999). The Source for Dyslexia and Dysgraphia. Moline, IL: Lingui Systems
Swarbrick, J. & Marshall, A. (2004). The Everything Parent’s Guide To Children With Dyslexia: All You Need To Ensure Your Child’s Success. Avon, MA: F + W Publications, Inc.