Dyslexia

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Dyslexia
Classification and external resources
ICD-10 R48.0
ICD-9 315.02
OMIM 127700
DiseasesDB 4016
MedlinePlus 001406
Patient UK Dyslexia
MeSH D004410
Inferior parietal lobule - superior view animation – dyslexia neuroanatomy (frontal gyrus, temporal cortex not shown) neurological[1]

Dyslexia, also known as alexia[2] or developmental reading disorder,[3] is characterized by difficulty with learning to read and with differing comprehension of language despite normal or above-average intelligence.[4][5] This includes difficulty with phonological awareness, phonological decoding, processing speed, orthographic coding, auditory short-term memory, language skills and verbal comprehension, or rapid naming.[6][7]

Dyslexia is the most common learning difficulty.[8] Some see dyslexia as distinct from reading difficulties resulting from other causes, such as a non-neurological deficiency with hearing or vision, or poor reading instruction.[9] There are three proposed cognitive subtypes of dyslexia (auditory, visual and attentional), although individual cases of dyslexia are better explained by specific underlying neuropsychological deficits (e.g., attention deficit hyperactivity disorder, a visual processing disorder) and co-occurring learning difficulties (e.g., dyscalculia and dysgraphia).[10][11] Although it is considered to be a receptive (afferent) language-based learning disability, dyslexia also affects one's expressive (efferent) language skills.[12]

Classification[edit]

Internationally, dyslexia is designated as a cognitive disorder, related to reading and speech.[13] The National Institute of Neurological Disorders and Stroke definition describes it as "difficulty with spelling, phonological processing (the manipulation of sounds), or rapid visual-verbal responding."[5] There are many published definitions, and many of them are purely descriptive or embody causal theories, that encompass a variety of reading skills, deficits and difficulties with distinct causes rather than a single condition.[14]

Acquired dyslexia (alexia), can be caused by brain damage, stroke, and atrophy.[15] Forms of alexia include: pure alexia, surface dyslexia, semantic dyslexia, phonological dyslexia, and deep dyslexia.[16] Acquired surface dyslexia arises after brain damage in a previously literate person and results in pronunciation errors that indicate impairment of the lexical route.[15][17][18] Numerous symptom-based definitions of dyslexia suggest neurological approaches.[19]

Signs and symptoms[edit]

In early childhood, symptoms that correlate with a later diagnosis of dyslexia include delays in speech,[20] letter reversal or mirror writing, difficulty knowing left from right and difficulty with direction,[21][22] as well as being easily distracted by background noise.[23] This pattern of early distractibility is sometimes partially explained by the co-occurrence of dyslexia and attention deficit hyperactivity disorder (ADHD). Although this disorder occurs in approximately 5% of children, 25–40% of children with either dyslexia or ADHD meet criteria for the other disorder.[24][25]

Dyslexic children of school age may exhibit signs such as difficulty identifying or generating rhyming words, or counting syllables in words (which depend on phonological awareness).[26] They may also show signs of difficulty segmenting words into individual sounds or blending sounds to make words (phonemic awareness).[27] Difficulty with word retrieval or with naming things also feature.[28][29] They are commonly poor spellers, which has been called dysorthographia or dysgraphia (orthographic coding). Whole-word guesses and tendencies to omit or add letters or words when writing and reading are considered tell-tale signs.[30]

Problems persist into adolescence and adulthood and may be accompanied by trouble summarizing stories as well as with memorizing, reading aloud, and learning foreign languages. Adult dyslexics can read with good comprehension, although they tend to read more slowly than non-dyslexics and perform worse at spelling and nonsense word reading, a measure of phonological awareness.[31][32]

A common misconception about dyslexia assumes that dyslexic readers all write words backwards or move letters around when reading. In fact this only occurs among half of dyslexic readers.[33]

Language[edit]

The complexity of a language's orthography (i.e., its conventional spelling system, see orthographic depth) has a direct impact upon how difficult it is to learn to read that language.[34] English has a comparatively deep orthography within the Latin alphabet writing system, with a complex structure that employs spelling patterns of several levels: principally, letter-sound correspondences, syllables, and morphemes.[35] Other languages, such as Spanish, Italian and Finnish have mostly alphabetic orthographies that employ letter-sound correspondences, so-called shallow orthographies, making them relatively easy to learn.[34] English and French, by comparison, presents more of a challenge.[34][36] Logographic writing systems, notably Japanese and Chinese characters, have graphemes that are not linked directly to their pronunciation, which pose a different type of difficulty to the dyslexic learner.[37][38] Different neurological deficits may cause varying degrees of difficulty in learning one writing system when compared to another, as the neurological skills required to read, write, and spell can vary between systems.[37]

Associated conditions[edit]

Several learning disabilities often occur with dyslexia, but it is unclear whether these learning disabilities share underlying neurological causes with dyslexia.[39] These disabilities include:

  • Dysgraphia – A disorder which expresses itself primarily through writing or typing, although in some cases it may also affect eye–hand coordination, direction- or sequence-oriented processes such as tying knots or carrying out a repetitive task. In dyslexia, dysgraphia is often multifactorial, due to impaired letter writing automaticity, finger motor sequencing challenges, organizational and elaborative difficulties, and impaired visual word form which makes it more difficult to retrieve the visual picture of words required for spelling.[40][41]
  • Attention deficit disorder – A significant degree of comorbidity has been reported between ADHD and dyslexia or reading disorders;[42][43] it occurs in 12–24% of all individuals with dyslexia. Research studying the impact of interference on adults with and without dyslexia has revealed large differences in terms of attention deficits for adults with dyslexia, and has implications for teaching reading and writing to dyslexics in the future.[44]
  • Auditory processing disorder – A condition that affects the ability to process auditory information. Auditory processing disorder is a listening disability.[45][46] It can lead to problems with auditory memory and auditory sequencing. Many people with dyslexia have auditory processing problems and may develop their own logographic cues to compensate for this type of deficit. Auditory processing disorder is recognized as one of the major causes of dyslexia.[47][48]
  • Developmental coordination disorder – A neurological condition characterized by a marked difficulty in carrying out routine tasks involving balance, fine-motor control, kinesthetic coordination, difficulty in the use of speech sounds, problems with short-term memory and organization are typical of dyspraxics.[20][49]

Causes[edit]

Blurring and doubling are two common types of visual stress experienced by those with dyslexia[50]
Main article: Theories of dyslexia

Researchers have been trying to find the neurobiological basis of dyslexia since it was first identified in 1881.[51][52] An example of one of the problems dyslexics experience would be seeing letters clearly, this may be due to abnormal development of their visual nerve cells..[53]

Neuroanatomy[edit]

In the area of neurological research into dyslexia, modern neuroimaging techniques such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) : have produced a correlation between functional and structural differences in the brains of children with reading difficulties.[54] Some individuals with dyslexia show less electrical activation in parts of the left hemisphere of the brain involved in reading, which includes the inferior frontal gyrus, inferior parietal lobule, and middle and ventral temporal cortex.[55] Brain activation studies using PET to study language have produced a breakthrough in understanding of the neural basis of language over the past decade. A neural basis for the visual lexicon and for auditory verbal short-term memory components have been proposed,[56] with some implication that the observed neural manifestation of developmental dyslexia is task-specific (i.e., functional rather than structural). fMRIs in dyslexics have provided important data supporting the interactive role, of the cerebellum and cerebral cortex as well as other brain structures.[57][58]

Genetics[edit]

Genetic research into dyslexia and its inheritance has its roots in the examination of post-autopsy brains of people with dyslexia..[53] When they observed anatomical differences in the language center in a dyslexic brain, they showed microscopic cortical malformations known as ectopias and more rarely vascular micro-malformations, and in some instances these cortical malformations appeared as a microgyrus.[59] These studies and others[60] suggested abnormal cortical development which was presumed to occur before or during the sixth month of fetal brain development. Abnormal cell formations in dyslexics found on autopsy have also been reported in non-language cerebral and subcortical brain structures.[61]

Gene–environment interaction[edit]

Research has examined gene–environment interactions in reading disability through twin studies, which estimate the proportion of variance associated with environment and the proportion associated with heritability. Studies examining the influence of environmental factors such as parental education[62] and teacher quality[63] have determined that genetics has greater influence in supportive, rather than less optimal, environments.[64] Instead, it may just allow those genetic risk factors to account for more of the variance in outcome, because environmental risk factors that affect that outcome have been minimized.[64] As the environment plays a large role in learning and memory, it is likely that epigenetic modifications play an important role in reading ability. Animal experiments and measures of gene expression and methylation in the human periphery are used to study epigenetic processes, both of which have many limitations in extrapolating results for application to the human brain.[65]

Dual route hypothesis to reading[66]

Mechanisms[edit]

The dual-route theory of reading aloud was first described in the early 1970s.[66] This theory suggests that two separate mental mechanisms, or cognitive routes, are involved in reading aloud, with output of both mechanisms contributing to the pronunciation of a written stimulus.[67] One mechanism is the lexical route, which is the process whereby skilled readers can recognize known words by sight alone, through a “dictionary” lookup procedure.[68]The other mechanism is the nonlexical or sublexical route, which is the process whereby the reader can “sound out” a written word.[68][69] This is done by identifying the word's constituent parts (letters, phonemes, graphemes) and applying knowledge of how these parts are associated with each other, for example how a string of neighboring letters sound together.[66]

Diagnosis[edit]

Central dyslexias[edit]

Central dyslexias include surface dyslexia, semantic dyslexia, phonological dyslexia, and deep dyslexia.[70][71] ICD-10 reclassified the previous distinction between dyslexia (315.02 in ICD-9) and alexia (315.01 in ICD-9) into a single classification as R48.0. The terms are applied for developmental dyslexia and inherited dyslexia along with developmental aphasia and inherited alexia, which are now read as cognates in meaning and synonymous.[72]

Surface dyslexia[edit]

Main article: Surface dyslexia
Dyslexic brain vs normal brain[73]

In surface dyslexia, words whose pronunciations are 'regular' (highly consistent with their spelling e.g., mint) are read more accurately than words with irregular pronunciation, such as colonel.[74] Difficulty distinguishing homophones is diagnostic of some forms of surface dyslexia. This disorder is usually accompanied by (surface) agraphia and fluent aphasia.[75]

Phonological dyslexia[edit]

Main article: Phonological dyslexia

In phonological dyslexia, patients can read familiar words but have difficulty reading unfamiliar words (such as invented pseudo-words).[76] It is thought that they can recognize words by accessing lexical memory orthographically but cannot 'sound out' novel words. Phonological dyslexia is associated with lesions in varied locations within the territory of the middle cerebral artery. The superior temporal lobe is often also involved. Furthermore, dyslexics compensate by overusing a front-brain section, called Broca's area, associated with aspects of language and speech.[73] Research has pointed towards the theory that phonological dyslexia is a development of deep dyslexia. A treatment for phonological dyslexia is the Lindamood Phoneme Sequencing Program (LiPS). This program is based on a three-way sensory feedback process. The subject uses their auditory, visual, and oral skills to learn to recognize words and word patterns. This is considered letter-by-letter reading using a bottom-up processing technique. Case studies with a total of three patients found a significant improvement in spelling and reading ability after using LiPS.[77]

Deep dyslexia[edit]

See also: Deep dyslexia

Patients with deep dyslexia experience semantic paralexia (para-dyslexia) and phonological dyslexia, which happens when the patient reads a word, and says a related meaning instead of the denoted meaning.[78] Deep alexia is associated with clear phonological processing impairments.[15] Deep dyslexia is caused by lesions that are often widespread and include much of the left frontal lobe; specifically, research suggests that damage to the left perisylvian region of the frontal lobe causes deep dyslexia.[79]

Peripheral dyslexias[edit]

Peripheral dyslexias have been described as a type of acquired dyslexia which is marked by problems in processing the visual factors of terms and, not like other dyslexias, originates from an injury to the system of visual analysis.[80] Hemianopsia is associated with this condition and is a visual field loss on the left/right side of the vertical midline.[81]

Pure dyslexia[edit]

Main article: Pure alexia

Pure dyslexia (phonologically based),[82] also known as agnosic dyslexia, dyslexia without agraphia, and pure word blindness, is dyslexia due to difficulty recognizing written sequences of letters (such as words), or sometimes even letters. It is 'pure' because it is not accompanied by other (significant) language-related impairments. Pure dyslexia does not include speech, handwriting style, language, or comprehension impairments.[83] Pure dyslexia is caused by lesions on the visual word form area (VWFA). The VWFA is composed of the left lateral occipital sulcus and is activated during reading. A lesion in the VWFA stops transmission between the visual cortex and the left angular gyrus. It can also be caused by a lesion involving the left occipital lobe and the splenium of the corpus callosum. It is usually accompanied by a homonymous hemianopsia in the right side of the visual field..[81] Multiple oral re-reading (MOR) is a treatment for pure dyslexia. It is considered a top-down processing technique in which patients read and re-read texts a predetermined number of times or until reading speed or accuracy improves a predetermined amount.[84]

Hemianopic dyslexia[edit]

Commonly considered to derive from visual field loss due to damage to the primary visual cortex.[85] Sufferers may complain of slow reading but are able to read individual words normally. This is the most common form of peripheral alexia, and the form with the best evidence of the (possibility of) effective treatment.[86]

Neglect dyslexia[edit]

In neglect dyslexia, some letters are neglected (skipped or misread) during reading – most commonly the letters at the beginning or left side of words.[87] This alexia is associated with right parietal lesions. Use of prism glasses in treatment has been demonstrated to produce substantial benefit.[88]

Attentional dyslexia[edit]

People with attentional dyslexia complain of letter crowding or migration, sometimes blending elements of two words into one.[89] Patients perform better when word stimuli are presented in isolation rather than flanked by other words and letters. Using a large magnifying glass may help as this should reduce the effects of flanking interference from nearby words; however, no trials of this or indeed any other therapy for left parietal syndromes have been published.[90]

Management[edit]

Woodrow Wilson House dyslexia typewriter[91]

Through compensation strategies and therapy, dyslexic individuals can learn to read and write with educational support.[92] There are techniques and technical aids that can manage or even conceal symptoms of the disorder.[93] Removing stress and anxiety alone can sometimes improve written comprehension.[94] For dyslexia intervention with alphabet writing systems, the fundamental aim is to increase a child's awareness of correspondences between graphemes (letters) and phonemes (sounds), and to relate these to reading and spelling by teaching him or her to blend the sounds into words. It has been found that reinforced collateral training focused towards visual language (reading) and orthography (spelling) yields longer-lasting gains than mere oral phonological training.[95] Intervention early on while language areas in the brain are still developing is most successful in reducing long-term impacts of dyslexia. There is some evidence that the use of specially tailored fonts may provide some measure of assistance for people who have dyslexia.[96][97] Among these fonts are Dyslexie and OpenDyslexic, which were created with the notion that many of the letters in the Latin alphabet are visually similar and therefore confusing for people with dyslexia.[98] Dyslexie, along with OpenDyslexic, put emphasis on making each letter more unique to assist in reading.[98] Font design can have an effect on reading, reading time and the perception of legibility, this is true for all readers, including those who have dyslexia and those who don't. [99]

Epidemiology[edit]

Impaired-extraction-of-speech-rhythm-from-temporal-modulation-patterns-in-speech-in-Developmental Dyslexia-Audio4

The prevalence of dyslexia is unknown and estimates of its prevalence vary greatly, spanning 1–33% of the population.[100] Most prevalence estimates for dyslexia span 5–10% of a given population, although no studies have indicated an exact percentage.[101]Internationally, there are differing definitions of dyslexia, but despite the significant differences between the writing systems, different speaking populations suffer similarly from dyslexia.[102] Dyslexia is not limited to difficulty in converting letters into sounds, but Chinese dyslexics have difficulty in extracting shapes of Chinese characters into meanings.[103]

History[edit]

A summary version of the map above,[104] showing predominant forms of writing systems by country and what their characters represent:
  Alphabet (consonants and vowels)
  Abjad (only consonants)
  Abugida (family-related syllables)
  Syllabary (isolated syllables)

Dyslexia was identified by Oswald Berkhan in 1881,[51] but the term dyslexia was coined in 1887 by Rudolf Berlin, who was an ophthalmologist in Stuttgart.[105] He used the term to refer to a case of a young boy who had a severe impairment in learning to read and write in spite of showing typical intellectual and physical abilities in all other respects.[106] In 1896, W. Pringle Morgan, a British physician from Seaford, East Sussex, published a description of a reading-specific learning disorder in a report to the British Medical Journal titled "Congenital Word Blindness".[107] The distinction between phonological and surface types of Dyslexia is only descriptive, and devoid of any etiological assumption as to the underlying brain mechanisms. Studies have, however, alluded to potential differential underlying brain mechanisms in these populations given performance differences.[108]

Research[edit]

Main article: Dyslexia research

The majority of currently available dyslexia research relates to the alphabetic writing system, and especially to languages of European origin.[109] However, substantial research is also available regarding dyslexia for speakers of Arabic, Chinese, Hebrew, as well as other languages.[110]

See also[edit]

References[edit]

  1. ^ Paulesu, Eraldo; Danelli, Laura; Berlingeri, Manuela (November 2014). "Reading the dyslexic brain: multiple dysfunctional routes revealed by a new meta-analysis of PET and fMRI activation studies". Frontiers in Human Neuroscience 8. doi:10.3389/fnhum.2014.00830. PMC 4227573. PMID 25426043. 
  2. ^ Joseph I. Sirven (Professor of Neurology Mayo Clinic); Barbara L. Malamut (2008). Clinical Neurology of the Older Adult. Lippincott Williams & Wilkins. p. 135. ISBN 978-0-7817-6947-1. 
  3. ^ "Developmental reading disorder". A.D.A.M. Medical Encyclopedia. 2013. Retrieved 23 January 2014. 
  4. ^ Nyirenda, Teresa (2011). A miracle life. Author House. p. 21. Retrieved 14 February 2015. 
  5. ^ a b "Dyslexia Information Page". National Institute of Neurological Disorders and Stroke. 12 May 2010. Retrieved 5 July 2010. 
  6. ^ Bishop, D (March 2009). "Genes, cognition, and communication: insights from neurodevelopmental disorders.". Annals of the New York Academy of Sciences. 1156(1): 1–18. Retrieved 11 February 2015. 
  7. ^ Eicher, John (November 2013). "Imaging-genetics in dyslexia: connecting risk genetic variants to brain neuroimaging and ultimately to reading impairments". Molecular Genetics and Metabolism. 110(3): 201–212. Retrieved 11 February 2015. 
  8. ^ Darcy Ann Umphred; Rolando T. Lazaro; Margaret Roller; Gordon Burton (2013). Neurological Rehabilitation. Elsevier Health Sciences. p. 383. ISBN 978-0-323-26649-9. 
  9. ^ Stoodley, CJ (December 2008). "Implicit learning in control, dyslexic, and garden-variety poor readers.". Annals The New York Academy of Sciences: 173–183. doi:10.1196/annals.1416.003. Retrieved 6 February 2015. 
  10. ^ Ahissar, Merav (November 2007). "Dyslexia and the anchoring-deficit hypothesis". Trends in Cognitive Sciences 11 (11): 458–65. doi:10.1016/j.tics.2007.08.015. PMID 17983834. 
  11. ^ Chung, K. K.; Ho, C. S.; Chan, D. W.; Tsang, S. M.; Lee, S. H. (February 2010). "Cognitive profiles of Chinese adolescents with dyslexia". Dyslexia 16 (1): 2–23. doi:10.1002/dys.392. PMID 19544588. 
  12. ^ Handler, S. M.; Fierson, W. M.; Section On, Ophthalmology; Council on Children with Disabilities; American Academy Of, Ophthalmology; American Association for Pediatric Ophthalmology Strabismus; American Association of Certified Orthoptists (March 2011). "Learning disabilities, dyslexia, and vision". Pediatrics 127 (3): e818–56. doi:10.1542/peds.2010-3670. PMID 21357342. 
  13. ^ Robert Jean Campbell M.D. (Professor of Psychiatry at Cornell-Weill Medical College) (2009). Campbell's Psychiatric Dictionary. Oxford University Press. pp. 310–312. ISBN 978-0-19-534159-1. 
  14. ^ Lyytinen, Heikki (November 2009). "In Search of a Science Based Application:Learning Tool for Reading Acquisition". Scandanavian Journal of Psychology. 50(6): 668–675. Retrieved 11 February 2015. 
  15. ^ a b c Woollams A (2014). "Connectionist neuropsychology: uncovering ultimate causes of acquired dyslexia". Philos. Trans. R. Soc. Lond., B, Biol. Sci. 369 (1634): 20120398. doi:10.1098/rstb.2012.0398. PMC 3866427. PMID 24324241. 
  16. ^ Michael Spivey; Marc Joanisse; Ken McRae (2012). The Cambridge Handbook of Psycholinguistics. Cambridge University Press. pp. 219–220. ISBN 978-0-521-67792-9. 
  17. ^ Harley, Trevor (2014). The Psychology of Language: From Data to Theory (4th ed.). Psychology Press. p. 227. Retrieved 14 February 2015. 
  18. ^ Wandell, Brian (January 2012). "Learning to See Words". Annual Review of Psychology: 31–53. Retrieved 13 February 2015. 
  19. ^ John Stein; Zoï Kapoula (2012). Visual Aspects of Dyslexia. Oxford University Press. p. 1. ISBN 978-0-19-163633-2. 
  20. ^ a b Huc-Chabrolle, M; Barthez, M. A.; Tripi, G; Barthélémy, C; Bonnet-Brilhault, F (April 2010). "Les troubles psychiatriques et psychocognitifs associés à la dyslexie de développement : un enjeu clinique et scientifique" [Psychocognitive and psychiatric disorders associated with developmental dyslexia: A clinical and scientific issue]. L'Encéphale (in French) 36 (2): 172–9. doi:10.1016/j.encep.2009.02.005. PMID 20434636. INIST:22769939. 
  21. ^ Hiroshi, Hamada (December 2014). "Mechanisms of left-right asymmetry and patterning: driver, mediator and responder". F1000 Prime Reports. Retrieved 13 February 2015. 
  22. ^ Schott, G. D. (January 2007). "Mirror writing: neurological reflections on an unusual phenomenon". J. Neurol. Neurosurg. Psychiatr. 78 (1): 5–13. doi:10.1136/jnnp.2006.094870. PMC 2117809. PMID 16963501. 
  23. ^ Garcia, Vera Lucia (June 2007). "Selective attention - psi performance in children with learning disabilities". Revista Brasileira de Otorrinolaringologia. 73(3). doi:10.1590/S0034-72992007000300017. Retrieved 6 February 2015. 
  24. ^ Marguerite, Matthews (July 2014). "Attention Deficit Hyperactivity Disorder". Current Topics in Behavioral Neuroscience: 235–266. Retrieved 13 February 2015. 
  25. ^ Willcutt, E. G.; Betjemann, R. S.; McGrath, L. M.; Chhabildas, N. A.; Olson, R. K.; Defries, J. C.; Pennington, B. F. (2010). "Etiology and neuropsychology of comorbidity between RD and ADHD: The case for multiple-deficit models". Cortex 46 (10): 1345–1361. doi:10.1016/j.cortex.2010.06.009. PMC 2993430. PMID 20828676. 
  26. ^ Facoetti, A; Corradi, N; Ruffino, M; Gori, S; Zorzi, M (27 July 2010). "Visual spatial attention and speech segmentation are both impaired in preschoolers at familial risk for developmental dyslexia". Dyslexia 16 (3): 226–239. doi:10.1002/dys.413. PMID 20680993. 
  27. ^ Lovio, R; Näätänen, R; Kujala, T (June 2010). "Abnormal pattern of cortical speech feature discrimination in 6-year-old children at risk for dyslexia". Brain Res. 1335: 53–62. doi:10.1016/j.brainres.2010.03.097. PMID 20381471. 
  28. ^ Hu, W (June 2010). "Developmental dyslexia in Chinese and English populations: dissociating the effect of dyslexia from language differences.". Brain. 133(6): 1694–1706. Retrieved 6 February 2015. 
  29. ^ Jones, Manon W.; Branigan, Holly P.; Kelly, M. Louise (2009). "Dyslexic and nondyslexic reading fluency: Rapid automatized naming and the importance of continuous lists". Psychonomic Bulletin & Review 16 (3): 567–72. doi:10.3758/PBR.16.3.567. PMID 19451386. 
  30. ^ Ise, E; Schulte-Körne, G (June 2010). "Spelling deficits in dyslexia: evaluation of an orthographic spelling training". Ann Dyslexia 60 (1): 18–39. doi:10.1007/s11881-010-0035-8. PMID 20352378. 
  31. ^ Jarrad, Lum (October 2013). "Procedural learning is impaired in dyslexia: evidence from a meta-analysis of serial reaction time studies.". Research of Developmental Disabilities: 3460–76. Retrieved 13 February 2015. 
  32. ^ Ferrer, E; Shaywitz, B. A.; Holahan, J. M.; Marchione, K; Shaywitz, S. E. (January 2010). "Uncoupling of reading and IQ over time: empirical evidence for a definition of dyslexia". Psychol Sci 21 (1): 93–101. doi:10.1177/0956797609354084. PMID 20424029. 
  33. ^ Nancy Mather; Barbara J. Wendling; Alan S Kaufman, Ph.D. (20 September 2011). Essentials of Dyslexia Assessment and Intervention. John Wiley & Sons. pp. 28–. ISBN 978-1-118-15266-9. Retrieved 10 April 2012. 
  34. ^ a b c Nicola Brunswick; Sine McDougall; Paul de Mornay Davies (2010). Reading and Dyslexia in Different Orthographies. Psychology Press. p. 266. ISBN 978-1-135-16781-3. 
  35. ^ David K. Dickinson; Susan B. Neuman (2013). Handbook of Early Literacy Research. Guilford Publications. p. 421. ISBN 978-1-4625-1470-0. 
  36. ^ Vogel, Alecia (March 2014). "VWFA,It's Not Just for Words Anymore". Frontiers in Human Neuroscience. Retrieved 13 February 2015. 
  37. ^ a b Seki, A; Kassai, K; Uchiyama, H; Koeda, T (March 2008). "Reading ability and phonological awareness in Japanese children with dyslexia". Brain Dev. 30 (3): 179–88. doi:10.1016/j.braindev.2007.07.006. PMID 17720344. 
  38. ^ Siok, Wai Ting; Niu, Zhendong; Jin, Zhen; Perfetti, Charles A.; Tan, Li Hai (2008). "A structural-functional basis for dyslexia in the cortex of Chinese readers". Proceedings of the National Academy of Sciences 105: 5561. Bibcode:2008PNAS..105.5561S. doi:10.1073/pnas.0801750105. 
  39. ^ Nicolson, R. I.; Fawcett, A. J. (September 2009). "Dyslexia, dysgraphia, procedural learning and the cerebellum". Cortex 47 (1): 117–27. doi:10.1016/j.cortex.2009.08.016. PMID 19818437. 
  40. ^ Bhattacharyya, S.; Cai, X.; Klein, J. P. (2014). "Dyscalculia, Dysgraphia, and Left-Right Confusion from a Left Posterior Peri-Insular Infarct". Behavioural Neurology. doi:10.1155/2014/823591. PMC 4006625. PMID 24817791. 
  41. ^ Cecil R. Reynolds; Elaine Fletcher-Janzen (2007). Encyclopedia of Special Education. John Wiley & Sons. p. 771. ISBN 978-0-471-67798-7. 
  42. ^ Ronald Comer; Elizabeth Gould (January 19, 2010). Psychology Around Us. John Wiley & Sons. p. 1. ISBN 978-0-471-38519-6. 
  43. ^ Germanò, E; Gagliano, A; Curatolo, P (2010). "Comorbidity of ADHD and Dyslexia". Developmental Neuropsychology 35 (5): 475–493. doi:10.1080/87565641.2010.494748. PMID 20721770. 
  44. ^ Proulx, M. J.; Elmasry, H. M. (May 2014). "Stroop interference in adults with dyslexia". Neurocase: 1–5. doi:10.1080/13554794.2014.914544. PMID 24814960. 
  45. ^ Simone Aparecida Capellini (2007). Neuropsycholinguistic Perspectives on Dyslexia and Other Learning Disabilities. Nova Publishers. p. 94. ISBN 978-1-60021-537-7. 
  46. ^ Moore, D. R. (July 2011). "The diagnosis and management of auditory processing disorder". Lang Speech Hear Serv Sch 42 (3): 303–8. doi:10.1044/0161-1461(2011/10-0032). PMID 21757566. 
  47. ^ Pammer, K (January 2014). "Brain mechanisms and reading remediation: more questions than answers.". Scientifica. Retrieved 13 February 2015. 
  48. ^ Calderone, D (June 2014). "Entrainment of neural oscillations as a modifiable substrate of attention". Trends in Cognitive Science: 300–309. Retrieved 13 February 2015. 
  49. ^ Tracy Packiam Alloway; Susan E. Gathercole (2012). Working Memory and Neurodevelopmental Disorders. Psychology Press. p. 29. ISBN 978-1-135-42134-2. 
  50. ^ "Eyes And Dyslexia". British Dyslexia Association. Retrieved 5 February 2015. 
  51. ^ a b Berkhan O (1917). "Über die Wortblindheit, ein Stammeln im Sprechen und Schreiben, ein Fehl im Lesen" [About word blindness, adyslalia of speech and writing, a weakness in reading]. Neurologisches Centralblatt (in German) 36: 914–27. 
  52. ^ Gavin Reid; Angela Fawcett; Frank Manis; Linda Siegel (2008). The SAGE Handbook of Dyslexia. SAGE Publications. p. 127. ISBN 978-1-84860-037-9. 
  53. ^ a b Stein, John (2014). "Dyslexia: the Role of Vision and Visual Attention". Current Developmental Disorders Reports 1 (4): 267–80. PMC 4203994. PMID 25346883. 
  54. ^ Harry A. Whitaker (2010). Concise Encyclopedia of Brain and Language. Elsevier. p. 180. ISBN 978-0-08-096499-7. 
  55. ^ Pammer, Kristen (January 2014). "Brain mechanisms and reading remediation: more questions than answers". Scientifica. Retrieved 14 February 2015. 
  56. ^ Price, cathy (August 16, 2012). "A Review and Synthesis of the first 20 years of Pet and fMRI studies of heard Speech,Spoken Language and Reading". Neuroimage. 62(2): 816–847. doi:10.1016/j.neuroimage.2012.04.062. PMID 3398395. Retrieved 5 February 2015. 
  57. ^ Sharifi, S (May 2014). "Neuroimaging essentials in essential tremor: a systematic review.". Neuroimage Clinical: 217–231. Retrieved 13 February 2015. 
  58. ^ Brandler, William (February 2014). "The genetic relationship between handedness and neurodevelopmental disorders.". Trends in molecular medicine: 83–90. Retrieved 14 February 2015. 
  59. ^ Miriam Faust (Professor of Psychology at Bar Ilan University) (2012). The Handbook of the Neuropsychology of Language. John Wiley & Sons. pp. 941–943. ISBN 978-1-4443-3040-3. 
  60. ^ Benitez, A (November 2010). "Neurobiology and neurogenetics of dyslexia". Neurology (in spanish). PMID 21093706. Retrieved 13 February 2015. 
  61. ^ Kere, Julia (September 2014). "The molecular genetics and neurobiology of developmental dyslexia as model of a complex phenotype.". Biochemical and biophysical research communication: 236–43. Retrieved 14 February 2015. 
  62. ^ Friend, A; Defries, J. C.; Olson, R. K. (November 2008). "Parental Education Moderates Genetic Influences on Reading Disability". Psychol Sci. 19 (11): 1124–1130. doi:10.1111/j.1467-9280.2008.02213.x. PMC 2605635. PMID 19076484. 
  63. ^ Taylor, J.; Roehrig, A. D.; Hensler, B. Soden; Connor, C. M.; Schatschneider, C. (2010). "Teacher Quality Moderates the Genetic Effects on Early Reading". Science 328 (5977): 512–4. Bibcode:2010Sci...328..512T. doi:10.1126/science.1186149. PMC 2905841. PMID 20413504. 
  64. ^ a b Pennington, Bruce F.; McGrath, Lauren M.; Rosenberg, Jenni; Barnard, Holly; Smith, Shelley D.; Willcutt, Erik G.; Friend, Angela; Defries, John C.; Olson, Richard K. (January 2009). "Gene × Environment Interactions in Reading Disability and Attention-Deficit/Hyperactivity Disorder". Developmental Psychology 45 (1): 77–89. doi:10.1037/a0014549. PMC 2743891. PMID 19209992. 
  65. ^ Roth, Tania L.; Roth, Eric D.; Sweatt, J. David (September 2010). "Epigenetic regulation of genes in learning and memory". Essays in Biochemistry 48 (1): 263–74. doi:10.1042/bse0480263. PMID 20822498. 
  66. ^ a b c Pritchard SC, Coltheart M, Palethorpe S, Castles A; Coltheart; Palethorpe; Castles (October 2012). "Nonword reading: comparing dual-route cascaded and connectionist dual-process models with human data". J Exp Psychol Hum Percept Perform 38 (5): 1268–88. doi:10.1037/a0026703. PMID 22309087. 
  67. ^ Michael Eysenck; Mark T. Keane (2013). Cognitive Psychology 6e. Psychology Press. p. 373. ISBN 1-134-44046-4. 
  68. ^ a b Michael Eysenck; Mark T. Keane (2013). Cognitive Psychology 6e. Psychology Press. p. 450. ISBN 1-134-44046-4. 
  69. ^ Charles Hulme (Professor of Psychology at the University of York); R. Malatesha Joshi (Professor of Psychology at the University of York); Margaret J. Snowling (Professor of Psychology at the University of York) (2012). Reading and Spelling: Development and Disorders. Routledge. p. 151. ISBN 978-1-136-49807-7. 
  70. ^ Verga, Laura (September 2013). "How relevant is social interaction in second language learning". Frontiers in human Neuroscience. Retrieved 13 February 2015. 
  71. ^ Woollams, Anna (December 2013). "Connectionist neuropsychology: uncovering ultimate causes of acquired dyslexia". Philosophical Translations of the Royal Society of London. Retrieved 13 February 2015. 
  72. ^ Brandler, William M.; Paracchini, Silvia (2014). "The genetic relationship between handedness and neurodevelopmental disorders". Trends in Molecular Medicine 20 (2): 83. doi:10.1016/j.molmed.2013.10.008. PMID 24275328. 
  73. ^ a b Heim, Stefan; Wehnelt, Anke; Grande, Marion; Huber, Walter; Amunts, Katrin (May 2013). "Effects of lexicality and word frequency on brain activation in dyslexic readers". Brain and Language 125 (2): 194–202. doi:10.1016/j.bandl.2011.12.005. PMID 22230039. 
  74. ^ Wilson, Stephen (March 2013). "Dysfunctional visual word form processing in progressive alexia". Brain: 1260–73. Retrieved 7 February 2015. 
  75. ^ Johnson, Juliene (April 2013). "Jean-Martin Charcot’s role in the 19th century study of music aphasia". Brain: 1662–70. Retrieved 7 February 2015. 
  76. ^ Susan Ayers; Andrew Baum; Chris McManus; Stanton Newman, Kenneth Wallston, John Weinman, Robert West (2007). Cambridge Handbook of Psychology, Health and Medicine. Cambridge University Press. p. 689. ISBN 978-1-139-46526-7. 
  77. ^ Beeson, Pélagie M.; Rising, Kindle; Kim, Esther S.; Rapcsak, Steven Z. (April 2010). "A Treatment Sequence for Phonological Alexia/Agraphia". Journal of Speech, Language, and Hearing Research 53 (2): 450–68. doi:10.1044/1092-4388(2009/08-0229). PMC 3522177. PMID 20360466. 
  78. ^ Joseph M. Tonkonogy; Antonio E. Puente (2009). Localization of Clinical Syndromes in Neuropsychology and Neuroscience. Springer Publishing Company. p. 409. ISBN 978-0-8261-1968-1. 
  79. ^ Jeffries, Elizabeth (April 2007). "Do Deep Dyslexia , Dysgraphia,and Dysphasia share a common phonological impairment?". Neuropsycologia: 1553–70. Retrieved 7 February 2015. 
  80. ^ Levi, Dennis (February 2008). "Crowding an essential bottleneck for object recognition: a mini-review.". Vision Research: 635–54. Retrieved 14 February 2015. 
  81. ^ a b Yanoff, Myron (2009). Opthalmology (2nd ed.). Mosby Elsevier. p. 1092. ISBN 978-0-323-04332-8. Retrieved 14 February 2015. 
  82. ^ Thomas E. Brown (Professor of Psychiatry at Yale University School of Medicine) (2009). ADHD Comorbidities: Handbook for ADHD Complications in Children and Adults. American Psychiatric Pub. p. 236. ISBN 978-1-58562-158-3. 
  83. ^ Starrfelt, Randi; Ólafsdóttir, Rannveig Rós; Arendt, Ida-Marie (2013). "Rehabilitation of pure alexia: A review". Neuropsychological Rehabilitation 23 (5): 755–79. doi:10.1080/09602011.2013.809661. PMC 3805423. PMID 23808895. 
  84. ^ Ilias Papathanasiou; Patrick Coppens; Constantin Potagas (2012). Aphasia and Related Neurogenic Communication Disorders. Jones & Bartlett Publishers. p. 168. ISBN 978-1-4496-8435-8. 
  85. ^ François Boller; Jordan Grafman (2010). Handbook of Neuropsychology: Disorders of visual behavior. Gulf Professional Publishing. p. 31. ISBN 978-0-444-50369-5. 
  86. ^ Schuett, Susanne (2009). "The rehabilitation of hemianopic dyslexia". Nature Reviews Neurology 5 (8): 427–37. doi:10.1038/nrneurol.2009.97. PMID 19581901. 
  87. ^ Martha J. Farah; Graham Ratcliff (2013). The Neuropsychology of High-level Vision. Psychology Press. pp. 177–179. ISBN 978-1-135-80652-1. 
  88. ^ Comer, Ronald (2011). Psychology Around Us. RR Donnelly. p. 232. Retrieved 14 February 2015. 
  89. ^ Jean-Michel, H (August 2012). "Synaesthesia, subjective expression of a neuronal palimpsest?". Medicine Sciences (in French): 765–771. Retrieved 13 February 2015. 
  90. ^ Bogon, Johanna; Finke, Kathrin; Stenneken, Prisca (16 October 2014). "TVA-based assessment of visual attentional functions in developmental dyslexia". Frontiers in Psychology. doi:10.3389/fpsyg.2014.01172. PMC 4199262. PMID 25360129. 
  91. ^ "Success Story: Woodrow Wilson". Dyslexia Help. University of Michigan. Retrieved 29 January 2015. 
  92. ^ Bogon, Johana (October 2014). "TVA based assessment of visual attention functions in developmental dyslexia". Frontiers in Psychology. Retrieved 13 February 2015. 
  93. ^ Nicola Brunswick (10 April 2012). Supporting Dyslexic Adults in Higher Education and the Workplace. John Wiley & Sons. pp. 115–. ISBN 978-0-470-97479-7. Retrieved 10 April 2012. 
  94. ^ Schulte-Körne, G (October 2010). "The prevention, diagnosis, and treatment of dyslexia". Dtsch Arztebl Int: 718–26. Retrieved 14 February 2015. 
  95. ^ Lyytinen, Heikki, Erskine, Jane, Aro, Mikko, Richardson, Ulla (2007). "Reading and reading disorders". In Hoff, Erika. Blackwell Handbook of Language Development. Blackwell. pp. 454–474. ISBN 978-1-4051-3253-4. 
  96. ^ Nalewicki, Jennifer (31 October 2011). "Bold Stroke: New Font Helps Dyslexics Read". Scientific American. Scientific American, a Division of Nature America, Inc. Retrieved 31 October 2011. 
  97. ^ de Leeuw, Renske (December 2010). "Special Font For Dyslexia?" (PDF) (in English/Dutch). University of Twente. p. 32. Archived from the original on 1 November 2011. 
  98. ^ a b Sawers, Paul. "Dyslexie: A typeface for dyslexics". Retrieved 9 April 2012. 
  99. ^ "3 Things to Know About Dyslexic Fonts". International Dyslexia Association. Retrieved 28 February 2015. 
  100. ^ Wei, Hu (May 2010). "Developmental dyslexia in Chinese and English populations: dissociating the effect of dyslexia from language differences". Brain: 1694–06. Retrieved 7 February 2015. 
  101. ^ Peterson, Robin (October 2009). "What influences literacy outcome in children with speech sound disorder?". Journal of speech, language and hearing research: 1175–88. Retrieved 14 February 2015. 
  102. ^ Protopapas, A (2013). "From temporal processing to developmental language disorders: mind the gap.". Philosophical transactions of the Royal Sociey of LondonSeries B, Biological Sciences. PMID 24324245. Retrieved 14 February 2015. 
  103. ^ Zhao, Jing (November 2014). "The visual magnocellular-dorsal dysfunction in Chinese children with developmental dyslexia impedes Chinese character recognition.". Scientific reports. Retrieved 14 February 2015. 
  104. ^ "Writing". Britannica. Encyclopædia Britannica. Retrieved 29 January 2015. 
  105. ^ "Über Dyslexie" [About dyslexia]. Archiv für Psychiatrie 15: 276–278. 1884. 
  106. ^ Annual of the Universal Medical Sciences and Analytical Index: A Yearly Report of the Progress of the General Sanitary Sciences Throughout the World. F. A. Davis Company. 1888. p. 39. 
  107. ^ Brooks, Patricia (2014). Encyclopedia of language development. SAGE. p. 30 (chronology). ISBN 978-1-4522-5876-8. Retrieved 14 February 2015. 
  108. ^ Mishra, S (October 2014). "Medial efferent mechanisms in children with auditory processing disorders.". Frontiers in human neuroscience. PMID 25386132. Retrieved 14 February 2015. 
  109. ^ Gavin Reid M.D (2012). The Routledge Companion to Dyslexia. Routledge. p. 16. ISBN 978-1-136-61710-2. 
  110. ^ Richlan, Fabio (May 2014). "Functional neuroanatomy of developmental dyslexia;the role of orthographic depth". Frontiers in human neuroscience. PMID 24904383. Retrieved 14 February 2015. 

Further reading[edit]

External links[edit]

Dyslexia associations