Annals of Dyslexia

, Volume 53, Issue 1, pp 1–14 | Cite as

A definition of dyslexia

  • G. Reid Lyon
  • Sally E. Shaywitz
  • Bennett A. Shaywitz
Part I Defining Dyslexia, Comorbidity, Teachers’ Knowledge Of Language And Reading

Abstract

This paper elaborates on the components of a working definition of developmental dyslexia. It follows the general format of a paper by Lyon published in Annals of Dyslexia in 1995, which elaborated on a working definition proposed in 1994 (Lyon, 1995). The current definition agreed on by the work group updates and expands on the working definition from 1994.

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References

  1. Benson, D. (1977). The third alexia. Archives of Neurology, 34, 327–331.Google Scholar
  2. Brown, W. E., Eliez, S., Menon, V., Rumsey, J. M., White, C. D., & Reiss, A. L. (2001). Preliminary evidence of widespread morphological variations of the brain in dyslexia. Neurology, 56(6), 781–783.Google Scholar
  3. Bruck, M. (1992). Persistence of dyslexics’ phonological awareness deficits. Developmental Psychology, 28, 874–886.CrossRefGoogle Scholar
  4. Brunswick, N., McCrory, E., Price, C. J., Frith, C. D., & Frith, U. (1999). Explicit and implicit processing of words and pseudowords by adult developmental dyslexics: A search for Wernicke’s Wortschatz? Brain, 122, 1901–1917.CrossRefGoogle Scholar
  5. Cohen, L., Dehaene, S., Naccache, L., Lehéricy, S., Dehaene-Lambertz, G., Hénaff, M.-A., & Michel, F. (2000). The visual word form area: Spatial and temporal characterization of an initial stage of reading in normal subjects and posterior split-brain patients. Brain, 123, 291–307.CrossRefGoogle Scholar
  6. Cohen, L., Lehéricy, S., Chochon, F., Lemer, C., Rivaud, S., & Dehaene, S. (2002). Language-specific tuning of visual cortex? Functional properties of the visual word form area. Brain, 125, 1054–1069.CrossRefGoogle Scholar
  7. Corina, D., Richards, T., Serafini, S., Richards, A., Steury, K., Abbott, R., et al. (2001). fMRI auditory language differences between dyslexic and able reading children. NeuoReport, 12, 1195–1201.CrossRefGoogle Scholar
  8. Damasio, A. R., & Damasio, H. (1983). The anatomic basis of pure alexia. Neurology, 33, 1573–1583.Google Scholar
  9. Dehaene, S., Le Clec’H, G., Poline, J., Le Bihan, D., & Cohen, L. (2002). The visual word form area: A prelexical representation of visual words in the fusiform gyrus. NeuroReport, 13, 1–5.CrossRefGoogle Scholar
  10. Dehaene, S., Naccache, L., Cohen, L., Le Bihan, D., Mangin, J., Poline, J., et al. (2001). Cerebral mechanisms of word masking and unconscious repetition priming. Nature Neuroscience, 4, 752–758.CrossRefGoogle Scholar
  11. Dejerine, J. (1891). Sur un cas de cécité verbale avec agraphie, suivi d’autopsie. C. R. Société du Biologie, 43, 197–201.Google Scholar
  12. Dejerine, J. (1892). Contribution a l’etude anatomo-pathologique et clinique des differentes varietes de cecite verbale. Memoires de la Societe de Biologie, 4, 61–90.Google Scholar
  13. Demb, J., Boynton, G., & Heeger, D. (1998). Functional magnetic resonance imaging of early visual pathways in dyslexia. Journal of Neuroscience, 18, 6939–6951.Google Scholar
  14. Eden, G. F., VanMeter, J. W., Rumsey, J. M., Maisog, J. M., Woods, R. P., & Zeffiro, T. A. (1996). Abnormal processing of visual motion in dyslexia revealed by functional brain imaging. Nature, 382, 66–69.CrossRefGoogle Scholar
  15. Eliez, S., Rumsey, J. M., Giedd, J. N., Schmitt, J. E., Patwardhan, A. J., & Reiss, A. L. (2000). Morphological alteration of temporal lobe gray matter in dyslexia: An MRI study. Journal of Child Psycholology and Psychiatry, 41(5), 637–644.CrossRefGoogle Scholar
  16. Filipek, P. (1996). Structural variations in measures in the developmental disorders. In R. Thatcher, G. Lyon, J. Rumsey, & N. Krasnegor (Eds.). Developmental neuroimaging: Mapping the development of brain and behavior (pp. 169–186). San Diego, CA: Academic Press.Google Scholar
  17. Fletcher, J. M., & Loveland, K. (1986). Neuropsychology of arithmetic disabilities in children. Focus on Learning Problems in Mathematics, 8, 23–40.Google Scholar
  18. Fletcher, J. M., Lyon, G. R., Barnes, M., Steubing, K. K., Francis, D. J., Olson, R. K., et al. (2002). Classification of learning disabilities: An evidence-based evaluation. In R. R. Bradley, L. Danielson, & D. Hallahan (Eds.). Identification of learning disabilities: Research to practice (pp. 185–250). Mahwah, NJ: Lawrence Erlbaum Associates.Google Scholar
  19. Fletcher, J. M., Shaywitz, S. E., Shankweiler, D. P., Katz, L., Liberman, I. Y., Stuebing, K. K., Francis, D. J., Fowler, A. E., & Shaywitz, B. A. (1994). Cognitive profiles of reading disability: Comparisons of discrepancy and low achievement definitions. Journal of Educational Psychology, 86, 6–23.CrossRefGoogle Scholar
  20. Friedman, R. F., Ween, J. E., & Albert, M. L. (1993). Alexia. In K. M. Heilman & E. Valenstein (Eds.). Clinical neuropsychology (3rd ed., pp. 37–62). New York: Oxford University Press.Google Scholar
  21. Galaburda, A. M., Sherman, G. F., Rosen, G. D., Aboitiz, F., & Geschwind, N. (1985). Developmental dyslexia: Four consecutive patients with cortical anomalies. Annals of Neurology, 18(2), 222–233.CrossRefGoogle Scholar
  22. Georgiewa, P., Rzanny, R., Hopf, J., Knab, R., Glauche, V., Kaiser, W., et al. (1999). fMRI during word processing in dyslexic and normal reading children. NeuroReport, 10, 3459–3465.CrossRefGoogle Scholar
  23. Geschwind, N. (1965). Disconnection syndromes in animals and man. Brain, 88, 237–294.CrossRefGoogle Scholar
  24. Gross-Glenn, K., Duara, R., Barker, W. W., Loewenstein, D., Chang, J.-Y., Yoshii, F., et al. (1991). Positron emission tomographic studies during serial word-reading by normal and dyslexic adults. Journal of Clinical and Experimental Neuropsychology, 13(4), 531–544.Google Scholar
  25. Helenius, P., Tarkiainen, A., Cornelissen, P., Hansen, P. C., & Salmelin, R. (1999). Dissociation of normal feature analysis and deficient processing of letter-strings in dyslexic adults. Cerebral Cortex, 4, 476–483.CrossRefGoogle Scholar
  26. Horwitz, B., Rumsey, J. M., & Donohue, B. C. (1998). Functional connectivity of the angular gyrus in normal reading and dyslexia. Proceedings of the National Academy of Sciences, USA, 95, 8939–8944.CrossRefGoogle Scholar
  27. Klingberg, T., Hedehus, M., Temple, E., Salz, T., Gabrieli, J., Moseley, M., et al. (2000). Microstructure of temporo-parietal white matter as a basis for reading ability: Evidence from diffusion tensor magnetic resonance imaging. Neuron, 25, 493–500.CrossRefGoogle Scholar
  28. Lefly, D. L., & Pennington, B. F. (1991). Spelling errors and reading fluency in compensated adult dyslexics. Annals of Dyslexia, 41, 143–162.Google Scholar
  29. Lerner, J. (1989). Educational interventions in learning disabilities. Journal of the American Academy of Child and Adolescent Psychiatry, 28, 326–331.CrossRefGoogle Scholar
  30. Liberman, I. Y., & Shankweiler, D. (1991). Phonology and the beginning reader: A tutorial. In L. Rieben & C. A. Perfetti (Eds.). Learning to read: Basic research and its implications (pp. 24–42). Hillsdale, NJ: Lawrence Erlbaum Associates.Google Scholar
  31. Lindamood, P. (1994). Issues in researching the link between phonological awareness, learning disabilities, and spelling. In G. R. Lyon (Ed.). Frames of reference for the assessment of learning disabilities: New views on measurement issues (pp. 351–373). Baltimore: Paul H. Brookes Publishing Company.Google Scholar
  32. Logan, G. (1988). Toward an instance theory of automatization. Psychological Review, 95, 492–527.CrossRefGoogle Scholar
  33. Logan, G. (1997). Automaticity and reading: Perspectives from the instance theory of automatization. Reading and Writing Quarterly: Overcoming Learning Disabilities, 13, 123–146.Google Scholar
  34. Lyon, G. R. (1995). Toward a definition of dyslexia. Annals of Dyslexia, 45, 3–27.Google Scholar
  35. Lyon, G. R., Fletcher, J. M., & Barnes, M. C. (2003). Learning disabilities. In E. J. Mash & R. A. Barkley (Eds.). Child psychopathology (2nd ed., pp. 520–586). New York: Guilford Press.Google Scholar
  36. Lyon, G. R., Fletcher, J. M., Shaywitz, S. E., Shaywitz, B. A., Torgesen, J. K., Wood, F. B., Schulte, A., & Olson, R. K. (2001). Rethinking learning disabilities. In C. E. Finn, Jr., R. A. J. Rotherham & C. R. Hokanson, Jr. (Eds.). Rethinking special education for a new century (pp. 259–287). Washington, DC: Thomas B. Fordham Foundation and Progressive Policy Institute.Google Scholar
  37. McCandliss, B., Cohen, L., & Dehaene, S. (2003). The visual word form area: Expertise in reading in the fusiform gyrus. Trends in Cognitive Sciences, 7(7), 293–299.CrossRefGoogle Scholar
  38. Moats, L. (1994). Issues in researching the link between phonological awareness, learning disabilities, and spelling. In G. R. Lyon (Ed.). Frames of reference for the assessment of learning disabilities: New views on measurement issues (pp. 333–349). Baltimore: Paul H. Brookes Publishing Company.Google Scholar
  39. Moore, C. J., & Price, C. J. (1999). Three distinct ventral occiptotemporal regions for reading and object naming. NeuroImage, 10, 181–192.CrossRefGoogle Scholar
  40. Morris, R. D., Stuebing, K. K., Fletcher, J. M., Shaywitz, S. E., Lyon, G. R., Shankweiler, D. P., Katz, L., Francis, D. J., & Shaywitz, B. A. (1998). Subtypes of reading disability: Variability around a phonological core. Journal of Educational Psychology, 90, 347–373.CrossRefGoogle Scholar
  41. Orton, S. (1937). Reading, writing, and speech problems in children: A presentation of certain types of disorders in the development of the language faculty. New York: W.W. Norton.Google Scholar
  42. Paulesu, E., Démonet, J.-F., Fazio, F., McCrory, E., Chanoine, V., Brunswick, N., Cappa, S.F., Cossu, G., Habib, M., Frith, C.D., & Frith, U. (2001). Dyslexia: Cultural diversity and biological unity. Science, 291, 2165–2167.CrossRefGoogle Scholar
  43. Paulesu, E., Frith, U., Snowling, M., Gallagher, A., Morton, J., Frackowiak, R. S. J., & Frith, C. D. (1996). Is developmental dyslexia a disconnection syndrome? Evidence from PET scanning. Brain, 119, 143–157.CrossRefGoogle Scholar
  44. Price, C., Moore, C., & Frackowiak, R. S. J. (1996). The effect of varying stimulus rate and duration on brain activity during reading. NeuroImage, 3(1), 40–52.CrossRefGoogle Scholar
  45. Ramus, F., Rosen, S., Dakin, S., Day, B., Castellote, J., White, S., & Frith, U. (2003). Theories of developmental dyslexia: Insights from a multiple case study of dyslexic adults. Brain, 126, 841–865.CrossRefGoogle Scholar
  46. Report of the National Reading Panel (2000). Teaching children to read: An evidence based assessment of the scientific research literature on reading and its implications for reading instruction (Vol. NIH Pub. No. 00-4754): Washington, DC: U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, National Institute of Child Health and Human Development.Google Scholar
  47. Rumsey, J. M., Andreason, P., Zametkin, A. J., Aquino, T., King, C., Hamburber, S. D., et al. (1992). Failure to activate the left temporoparietal cortex in dyslexia. Archives of Neurology, 49, 527–534.Google Scholar
  48. Rumsey, J. M., Nace, K., Donohue, B., Wise, D., Maisog, J. M., & Andreason, P. (1997). A positron emission tomographic study of impaired word recognition and phonological processing in dyslexic men. Archives of Neurology, 54, 562–573.Google Scholar
  49. Salmelin, R., Service, E., Kiesila, P., Uutela, K., & Salonen, O. (1996). Impaired visual word processing in dyslexia revealed with magnetoencephalography. Annals of Neurology, 40, 157–162.CrossRefGoogle Scholar
  50. Seki, A., Koeda, T., Sugihara, S., Kamba, M., Hirata, Y., Ogawa, T., & Takeshita, K. (2001). A functional magnetic resonance imaging study during sentence reading in Japanese dyslexic children. Brain & Development, 23, 312–316.CrossRefGoogle Scholar
  51. Shankweiler, D., Crain, S., Katz, L., Fowler, A. E., Liberman, A. M., Brady, S. A., Thornton, R., Lundquist, E., Dreyer, L., Fletcher, J. M., Stuebing, K. K., Shaywitz, S. E., & Shaywitz, B. A. (1995). Cognitive profiles of reading-disabled children: Comparison of language skills in phonology, morphology, and syntax. Psychological Science, 6, 149–156.CrossRefGoogle Scholar
  52. Shaywitz, B. A., Fletcher, J. M., & Shaywitz, S. E. (1994). A conceptual framework for learning disabilities and attention-deficit hyperactivity disorder. Canadian Journal of Special Education, 9(3), 1–32.Google Scholar
  53. Shaywitz, B. A., Shaywitz, S. E., Pugh, K. R., Mencl, W. E., Fulbright, R. K., Skudlarski, P., Constable, R. T., Marchione, K. E., Fletcher, J. M., Lyon, G. R., & Gore, J. C. (2002). Disruption of posterior brain systems for reading in children with developmental dyslexia. Biological Psychiatry, 52, 101–110.CrossRefGoogle Scholar
  54. Shaywitz, S. (2003). Overcoming dyslexia: A new and complete science-based program for reading problems at any level. New York: Alfred A. Knopf.Google Scholar
  55. Shaywitz, S. E., Fletcher, J. M., Holahan, J. M., Shneider, A. E., Marchione, K. E., Stuebing, K. K., Francis, D. J., Pugh, K. R., & Shaywitz, B.A. (1999). Persistence of dyslexia: The Connecticut longitudinal study at adolescence. Pediatrics, 104, 1351–1359.CrossRefGoogle Scholar
  56. Shaywitz, S. E., Shaywitz, B. A., Fulbright, R. K., Skudlarski, P., Mencl, W. E., Constable, R. T., Pugh, K. R., Holahan, J. M., Marchione, K. E., Fletcher, J. M., Lyon, G. R., & Gore, J. C. (2003). Neural systems for compensation and persistence: Young adult outcome of childhood reading disability. Biological Psychiatry, 54, 25–33.CrossRefGoogle Scholar
  57. Shaywitz, S. E., Shaywitz, B. A., Pugh, K. R., Fulbright, R. K., Constable, R. T., Mencl, W. E., Shankweiler, D. P., Liberman, A. M., Skudlarski, P., Fletcher, J. M., Katz, L., Marchione, K. E., Lacadie, C., Gatenby, C., & Gore, J. C. (1998). Functional disruption in the organization of the brain for reading in dyslexia. Proceedings of the National Academy of Sciences, USA, 95, 2636–2641.CrossRefGoogle Scholar
  58. Simos, P., Breier, J., Fletcher, J., Bergman, E., & Papanicolaou, A. (2000). Cerebral mechanisms involved in word reading in dyslexic children: A magnetic source imaging approach. Cerebral Cortex, 10, 809–816.CrossRefGoogle Scholar
  59. Stanovich, K. E., & Siegel, L. S. (1994). Phenotypic performance profile of children with reading disabilities: A regression-based test of the phonological-core variable-difference model. Journal of Educational Psychology, 86(1), 24–53.CrossRefGoogle Scholar
  60. Stein, J., & Walsh, V. (1997). To see but not to read: The magnocellular theory of dyslexia. Trends in Neurosciences, 20(4), 147–152.CrossRefGoogle Scholar
  61. Talcott, J. B., Witton, C., McLean, M. F., Hansen, P. C., Rees, A., Green, G. G. R., & Stein, J. F. (2000). Dynamic sensory sensitivity and children’s word decoding skills. Proceedings of the National Academy of. Sciences, USA, 97, 2952–2957.CrossRefGoogle Scholar
  62. Tallal, P. (2000). The science of literacy: From the laboratory to the classroom. Proceedings of the National Academy of Sciences. USA, 97, 2402–2404.CrossRefGoogle Scholar
  63. Temple, E., Poldrack, R.A., Salidas, J., Deutsch, G. K., Tallal, P., Merzenich, M. M., & Gabrieli, J. D. (2001). Disrupted neural responses to phonological and orthographic processing in dyslexic children: An fMRI study. NeuroReport, 12, 299–307.CrossRefGoogle Scholar
  64. Torgesen, J. K. (2000). Individual differences in response to early interventions in reading: The lingering problem of treatment resisters. Learning Disabilities Research & Practice, 1, 55–64.CrossRefGoogle Scholar
  65. U.S. Office of Education (USOE) (1977). Definition and criteria for defining students as learning disabled. Washington, DC: U.S. Government Printing Office.Google Scholar
  66. Wolf, M., Bowers, P. G., & Biddle, K. (2001). Naming speed processes, timing, and reading: A conceptual review. Journal of Learning Disabilities, 33, 387–407.Google Scholar

Copyright information

© The International Dyslexia Association 2003

Authors and Affiliations

  • G. Reid Lyon
    • 1
  • Sally E. Shaywitz
    • 2
  • Bennett A. Shaywitz
    • 2
  1. 1.National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesda
  2. 2.Yale University School of MedicineNew Haven

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