Developmental Dyslexia

1. Developmental Dyslexia Laurie Philbeck

2. Definition of Dyslexia • Dyslexia or specific reading disability is neurobiological in origin and is characterized by difficulties with accurate and/or fluent word recognition, poor spelling, and decoding abilities. • Difficulties result from a deficit in the phonological component of language that is unexpected in relation to other cognitive abilities and the provision of effective classroom instruction. • (Shaywitz, 2008)

3. Phonological Awareness Difficulty • Children with dyslexia have difficulty hearing the phonemes within words, resulting in difficulty learning to associate the letters with specific sounds within each word. • Thus the word “bat” is composed of three phonemes, “b”, “aaa”, and “t” but the listener hears this as the holistic word “bat” and not as three separate sounds. • Shaywitz (2008)

4. Degree and Course of Dyslexia • Like hypertension and obesity, dyslexia occurs in degrees of severity. • Dyslexia follows an unremitting course (meaning a child can not outgrow it) causing early intervention to take on a new urgency.

5. Comorbidity • Between dyslexia and ADHD ranging from 15% to 50%

6. Genetic Influence • Dyslexia is heritable. • The disorder is found in 23% to 65% of the children of parents who are dyslexic • 40% of the siblings of a dyslexic child are affected • If a child or parent has a sibling who is dyslexic, that child should be considered at risk and observed carefully for signs of a reading difficulty. • Shaywitz (2008)

7. Symptoms • Late speaking, mispronunciations, difficulties with word retrieval, needing time to summon an oral response, confusing words that sound alike, such as saying recession for reception. Slow reading, difficulties in spelling, handwriting. • Thinking, reasoning, vocabulary, and listening comprehension are intact.

8. Brain Imaging Studies • Sally Shaywitz (2002) had 70 dyslexic children and 74 non-dyslexic children read words and pronounceable non-words while in fMRI. • Shaywitz and other neuroscientists have been able to identify and localize several interrelated left hemisphere neural networks in reading. • Three systems are evident: Broca’s area, Wernicke’s area, and posterior occipito-temporal region

10. Neural Signature for DyslexiaSchematic view of left hemisphere brain systems for reading observed during fMRI Figure reprinted from (Shaywitz 2003)

12. Compensate • Develop compensatory systems involving areas around the inferior frontal gyrus in both hemispheres as well as the right hemisphere homologue of the left occipito-temporal word form area. • Shaywitz (2008)

14. Wait-to-Fail Model • Schools have typically relied on the discrepancy model requiring a discrepancy between the child’s measured IQ and reading achievement in order for children to receive services. • Problem with discrepancy model is because children who are clearly struggling as early as kindergarten or first grade have to wait until the third grade or later when their failure in reading becomes of such a magnitude that they meet discrepancy requirements. • (Shaywitz, 2008).

15. Early Intervention • Window of Time -When the student becomes around 9 to 11 years old the temporal lobe loses its plasticity causing it to become hard wired. • We are born with more neurons then we need that are attune to any sound in the world, however as we are exposed the given language of our household those neurons are wired and fired together allowing other unused neurons to discard(brains pruning approach). • Dr. Steven Feifer (2010 NASP Conference)

16. Early Intervention • Evidence-based reading intervention at an early age improves reading fluency and facilitates the development of those neural systems that underlie skilled reading. • Fluency focused intervention requires significant reading of connected text with scaffolding support by either peers or teachers. • Prevention programs focus on phonemic awareness, phonics, and meaning of text in the earliest grades of reading instruction.

17. Early Intervention • Interventions focus on word decoding and single word identification levels have had the most consistent effectiveness particularly in prevention in early childhood studies. • Explicit, intense, systematic, and developmentally appropriate multi-focused, evidence-based interventions are effective.

18. Effective Instruction • According to National Reading Panel in 2000, they found five essential elements should be incorporated into effective reading instruction: Phonemic Awareness, Phonics, Fluency, Vocabulary and Comprehension. These should be taught systematically and explicitly. • Explicit instruction in speech sound awareness and sound symbol association helps to prevent reading failure (Eden and Moats, 2002)

19. Effective Instruction • Students should be encouraged to read a lot and often to support the development of fluent and automatic reading.

20. Diagnosis and Tests • Dyslexia is a clinical diagnosis best made by a experienced clinician who has taken a careful history, observed the child read and administered a battery of tests to assess cognitive, academic including reading accuracy, fluency, comprehension, spelling, and mathematics (often a high skill), language skills particularly phonological processing. • Tests of reading fluency of how quickly and accurately individual words and passages are read.

21. Tests • Tests for Phonological Awareness can be given by asking the child to repeat a word after omitting one of its sounds. For example “cat” without the /k/ or “Germany” without the /m/ • Eden and Moats (2002)

22. Repairing Neural Systems • Brain imaging is used as a tool to examine the influences of reading instruction on the development or reorganization (repair) of these neural systems. • Study of second and third grade dyslexic and non-impaired readers, compared with dyslexic readers who received other types of intervention, • children who received an experimental evidence-based phonological intervention improved their reading and demonstrated increased activation both in left anterior (inferior frontal gyrus) and left posterior (middle temporal gyrus) brain regions (Shaywitz 2004).

23. Accommodations • To keep up with classmates and increase knowledge: access to recorded materials such as books on tape etc. • Extra time for examinations since that extra time is needed for reading since it is not automatic and fluent. • Need quiet separate rooms for testing since they are non-automatic readers who need to call upon their attentional resources during reading

24. Executive Functions • (Reiter, Tucha, and Lange, 2004) tested 42 children with dyslexia and 42 non-dyslexic children using a neuropsychological test battery consisting of standardized tests examining assessment of working memory, concept formation, inhibition, flexibility, problem solving and fluency functions. • Children with dyslexia reveled obvious difficulties with tests measuring working memory, inhibition of inappropriate reactions, and verbal and fluency functions.

25. For Teachers and Staff • Dyslexic readers rely on memory rather than understanding how letters link to sounds, problem is that their memory has a limited capacity. • Lack of reading fluently or automatically brings a need to read manually which is a process that consumes great effort. • When teachers ask students to read silently, students with dyslexia will appear to be daydreaming or not attending to the assigned reading because they are depleting their attentional resources

26. References Guinevere, E. F., Moats, L. (2002). The role of neuroscience in the remediation of students with dyslexia. Nature Neuroscience Supplement, 5, 1080-1084. Reiter, A., Tucha, O., Lange, K., W., (2004). Executive functions in children with dyslexia. Dyslexia, 11, 116-131. Shaywitz, S. E., Morris, R., Shaywitz, B. A., (2008). The education of dyslexic children from childhood to young adulthood. Annual Review of Psychology, 59, 451-475