|Classification and external resources|
Dyslexia is characterized by difficulty in learning to read fluently and with inaccurate comprehension despite normal intelligence. This includes difficulty with phonological awareness, phonological decoding, processing speed, orthographic coding, auditory short-term memory, language skills/verbal comprehension, and/or rapid naming.
Developmental reading disorder (DRD), or dyslexia, is the most common learning disability.
Adult dyslexics can read with good comprehension, although they tend to read more slowly than non-dyslexics and perform more poorly at spelling and nonsense word reading, a measure of phonological awareness.
Some see dyslexia as distinct from reading difficulties resulting from other causes, such as a non-neurological deficiency with vision or hearing, or from poor or inadequate reading instruction. 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 and co-occurring learning disabilities (e.g. attention-deficit/hyperactivity disorder, math disability, etc.). Although it is considered to be a receptive language-based learning disability in the research literature, dyslexia also affects one's expressive language skills. Researchers at MIT found that people with dyslexia exhibited impaired voice-recognition abilities. It is believed the prevalence of dyslexia is around 5-10 percent of a given population although there have been no studies to indicate an accurate percentage.
The World Federation of Neurology defines dyslexia as "a disorder manifested by difficulty in learning to read despite conventional instruction, adequate intelligence and sociocultural opportunity".
The National Institute of Neurological Disorders and Stroke gives the following definition for dyslexia:
"Dyslexia is a brain-based type of learning disability that specifically impairs a person's ability to read. These individuals typically read at levels significantly lower than expected despite having normal intelligence. Although the disorder varies from person to person, common characteristics among people with dyslexia are difficulty with spelling, phonological processing (the manipulation of sounds), and/or rapid visual-verbal responding. In adults, dyslexia usually occurs after a brain injury or in the context of dementia. It can also be inherited in some families and recent studies have identified a number of genes that may predispose an individual to developing dyslexia."
Other published definitions are purely descriptive or embody causal theories. Varying definitions are used for dyslexia from researchers and organizations around the world; it appears that this disorder encompasses a number of reading skills, deficits and difficulties with a number of causes rather than a single condition.
Castles and Coltheart describe phonological and surface types of developmental dyslexia by analogy to classical subtypes of alexia (acquired dyslexia) which are classified according to the rate of errors in reading non-words. However, the distinction between surface and phonological dyslexia has not replaced the old empirical terminology of dysphonetic versus dyseidetic types of dyslexia. The surface/phonological distinction 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. The dysphonetic/dyseidetic distinction refers to two different mechanisms; one that relates to a speech discrimination deficit, and another that relates to a visual perception impairment.
However, some think that dyslexia can increase the capacity to think and perceive multi-dimensionally and can help further utilize the brain’s ability to alter and create perceptions.
Signs and symptoms
Some early symptoms that correlate with a later diagnosis of dyslexia include delays in speech, letter reversal or mirror writing, and being easily distracted by background noise. This pattern of early distractibility is partially explained by the co-occurrence of dyslexia and attention-deficit/hyperactivity disorder. Although each disorder occurs in approximately 5% of children, 25-40% of children with either dyslexia or ADHD meet criteria for the other disorder.
At later ages symptoms can include a difficulty identifying or generating rhyming words, or counting syllables in words (phonological awareness), a difficulty segmenting words into individual sounds, or blending sounds to make words, a difficulty with word retrieval or naming problems (see anomic aphasia), commonly very poor spelling, 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 classic signs. Other classic signs for teenagers and adults with dyslexia include trouble with summarizing a story, memorizing, reading aloud, and learning a foreign language.
A common misconception about dyslexia is that dyslexic readers write words backwards or move letters around when reading – this only occurs in a very small population of dyslexic readers. Individuals with dyslexia are better identified by reading accuracy, fluency, and writing skills that do not seem to match their level of intelligence from prior observations.
Dyslexia and biology
Researchers have been trying to find a biological basis of dyslexia since it was first identified by Oswald Berkhan in 1881 and the term dyslexia coined in 1887 by Rudolf Berlin. The theories of the etiology of dyslexia have and are evolving with each new generation of dyslexia researchers, and the more recent theories of dyslexia tend to enhance one or more of the older theories as understanding of the nature of dyslexia evolves (see Theories of dyslexia).
Effect of language orthography
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. English has a comparatively deep orthography within the Latin alphabet writing system, with a complex orthographic structure that employs spelling patterns at several levels: principally, letter-sound correspondences, syllables, and morphemes. Other languages, such as Spanish, have mostly alphabetic orthographies that employ letter-sound correspondences, so-called shallow orthographies. It is relatively easy to learn to read languages like Spanish; it is much more difficult to learn to read languages with more complex orthographies such as English. Logographic writing systems, notably Japanese and Chinese characters, have graphemes that are not linked directly to their pronunciation, which pose a different type of dyslexic difficulty.
From a neurological perspective, different types of writing systems (e.g. alphabetic as compared to logographic writing systems) require different neurological pathways in order to read, write, and spell. Because different writing systems require different parts of the brain to process the visual notation of speech, children with reading problems in one language might not have a reading problem in a language with a different orthography. The neurological skills required to perform the tasks of reading, writing, and spelling can vary between different writing systems. As a result, different neurological deficits can cause dyslexic problems in relation to different orthographies.
Cross-cultural study of the prevalence of dyslexia is difficult as different scholars and different countries often use different criteria to distinguish the cases of dyslexia in the continuum between the able and delayed readers at schools. According to the existing literature, the prevalence of dyslexia can vary widely between cultures. For example, Christall reports differences between 1% and 33%. According to some researchers, despite the significant differences between the writing systems, Italian, German and English populations suffer similarly from dyslexia.
Several learning disabilities often occur with dyslexia, but it is unclear whether these learning disabilities share underlying neurological causes with dyslexia. 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. Dysgraphia is distinct from dyspraxia in that dyspraxia is simply related to motor sequence impairment.
- Attention deficit disorder – a high degree of co-morbidity has been reported between ADD/ADHD and dyslexia/reading disorders, it occurs in between 12% and 24% of those with dyslexia.
- Auditory processing disorder – A condition that affects the ability to process auditory information. Auditory processing disorder is a listening disability. 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.
- Developmental dyspraxia – 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.
Experience of speech acquisition delays and speech and language problems can be due to problems processing and decoding auditory input prior to reproducing their own version of speech, and may be observed as stuttering, cluttering or hesitant speech.
Clinically reported findings requiring further substantiation suggested that most all the many coexisting writing, spelling, math, memory, speech, concentration, sensory, balance, coordination... symptoms and related co-morbid disorders found characterizing dyslexics were consistent with and likely determined by multiple overlapping cerebellar-vestibular dysfunctioning mechanisms. These symptoms and disorders were shown to respond favorably to cerebellar-vestibular stabilizing/enhancing medications and compensatory therapies. An alternative hypothesis suggests that dyslexia may reflect one syndrome of reading and non-reading symptoms of variable severities resulting when diversely scrambled sensory, motor and related signals of cerebellar-vestibular origin fail to be adequately processed by the varied reading and other brain structures modulating them. The normal to high IQ's, favorable prognosis and even gifted functioning in dyslexia appear more consistent with intact higher brain structures having significant neuroplastic capabilities compensating for scrambled signals of lower brain origin than the reverse: diffusely impaired higher brain structures and functions failing to process clear signals.
There is no cure for dyslexia, but dyslexic individuals can learn to read and write with educational support. There are techniques and technical aids that can manage or even conceal symptoms of the disorder. Removing stress and anxiety alone can improve written comprehension.
For dyslexia intervention with alphabet writing systems the fundamental aim is to increase a child's awareness of correspondences between graphemes and phonemes, and to relate these to reading and spelling. It has been found that training focused towards visual language and orthographic issues yields longer-lasting gains than mere oral phonological training.
There is some evidence that the use of specially tailored fonts may provide some measure of assistance for those suffering from dyslexia. Intervention early on while language areas in the brain are still developing is most successful in reducing long-term impacts of dyslexia.
Dyslexia was identified by Oswald Berkhan in 1881, but the term dyslexia was coined in 1887 by Rudolf Berlin, who was an ophthalmologist in Stuttgart. 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.
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". This described the case of Percy, a 14-year-old boy who had not yet learned to read, yet showed normal intelligence and was generally adept at other activities typical of children that age.
The majority of currently available dyslexia research relates to the alphabetic writing system, and especially to languages of European origin. However, substantial research is also available regarding dyslexia for speakers of Arabic, Chinese, and Hebrew.
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 clear evidence of structural differences in the brains of children with reading difficulties. It has been found that people with dyslexia have a deficit 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.
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, with some implication that the observed neural manifestation of developmental dyslexia is task-specific (i.e., functional rather than structural).
Genetic research into dyslexia has its roots in the examination of post-autopsy brains of people with dyslexia. 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. These studies and those of Cohen et al. 1989 suggested abnormal cortical development which was presumed to occur before or during the sixth month of fetal brain development.
Diverse ﬁndings appear incompatible with the theory suggesting that abnormal embryonic cell formations within the linguistic cerebral cortex have a primary role in causing dyslexia. Abnormal embryonic cell formations in dyslexics found on autopsy have also been reported in non-language cerebral and subcortical brain structures. MRI data have conﬁrmed a cerebellar role in dyslexia. Developmental dyslexia of genetic or prenatal origin has been highly correlated to a primary neurophysiological dysfunction or delayed maturation of the cerebellar and vestibular systems. Without any reasonable probability of newly and rapidly creating or dissolving primary abnormal embryonic (or other) cell formations within the brain: The acquired postnatal onset or intensiﬁcation of dyslexic reading and non-reading symptoms and related cerebellar-vestibular neurological and electronystagmographic diagnostic signs have been reported following acquired vestibular-based impairments triggered by ear and sinus infections, mononucleosis, benign paroxysmal positional vertigo, spinning and zero gravity as well as whiplash and post concussion states.:5-6, 45-48, 111-112, 326, 346-349:349
Dyslexia and its many reading and non-reading symptoms as well as their determining mechanisms have often shown rapid improvements when treated with cerebellar-vestibular stabilizing medications and related non-medical therapies. Discontinuing medication shortly after favorable therapeutic responses are obtained results in an immediate reappearance of all dyslexic symptoms and their determining mechanisms. These ﬁndings suggest an alternative possibility that the abnormal brain cells found in dyslexic brains secondarily result from the dyslexic process and its assumed primary cerebellar-vestibular causation.:349
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, and teacher quality have determined that genetics have greater influence in supportive, rather than less optimal environments. 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.
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 models and measures of gene expression and methylation in the human periphery are used to study epigenetic processes, both of which have limitations in extrapolating to the human brain.
Movies about dyslexia
- The term dyslexia can refer to an anomalous approach to processing information. Silverman, L. (2000). The two-edged sword of compensation: How the gifted cope with learning disabilities. In Uniquely gifted: Identifying and meeting the needs of twice exceptional learners, pages 153-159.
- "Dyslexia Information Page". National Institute of Neurological Disorders and Stroke. 12 May 2010. Retrieved 5 July 2010.
- Grigorenko, Elena L. (January 2001). "Developmental Dyslexia: An Update on Genes, Brains, and Environments". Journal of Child Psychology and Psychiatry 42 (1): 91–125. doi:10.1111/1469-7610.00704. PMID 11205626.
- Schulte-Körne G, Warnke A, Remschmidt H (November 2006). "[Genetics of dyslexia]". Z Kinder Jugendpsychiatr Psychother (in German) 34 (6): 435–44. doi:10.1024/1422-49220.127.116.115. PMID 17094062.
- Pennington, B.F.; Santerre-Lemon, L., Rosenberg, J., MacDonald, B., Boarda, R., Friend, A., Leopold, D.R., Samuelsson, S., Byrne, B., Willcutt, E.G., & Olson, R.K. (October 24, 2011). "Individual Prediction of Dyslexia by Single Versus Multiple Deficit Models". Journal of Abnormal Psychology 121 (1): 212–224. doi:10.1037/a0025823. PMID 22022952.
- Fink RP (1998). "Literacy development in successful men and women with dyslexia". Annals of Dyslexia 40 (1): 311–346.
- Ferrer E, Shaywitz BA, Holahan JM, Marchione K, Shaywitz SE (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.
- Stanovich KE (December 1988). "Explaining the differences between the dyslexic and the garden-variety poor reader: the phonological-core variable-difference model". Journal of Learning Disabilities 21 (10): 590–604. doi:10.1177/002221948802101003. PMID 2465364.
- Warnke, Andreas (19 September 1999). "Reading and spelling disorders: Clinical features and causes". Journal European Child & Adolescent Psychiatry 8 (3): S2–S12. doi:10.1007/PL00010689. Retrieved 11 July 2010.
- Czepita D, Lodygowska E (2006). "[Role of the organ of vision in the course of developmental dyslexia]". Klin Oczna (in Polish) 108 (1–3): 110–3. PMID 16883955.
- Valdois S, Bosse ML, Tainturier MJ (November 2004). "The cognitive deficits responsible for developmental dyslexia: review of evidence for a selective visual attentional disorder". Dyslexia 10 (4): 339–63. doi:10.1002/dys.284. PMID 15573964.
- Heim S, Tschierse J, Amunts K (2008). "Cognitive subtypes of dyslexia". Acta Neurobiologiae Experimentalis 68 (1): 73–82. ISSN 0065-1400. PMID 18389017.
- Facoetti A, Lorusso ML, Paganoni P et al. (April 2003). "Auditory and visual automatic attention deficits in developmental dyslexia". Brain Res Cogn Brain Res 16 (2): 185–91. doi:10.1016/S0926-6410(02)00270-7. PMID 12668226.
- Ahissar M (November 2007). "Dyslexia and the anchoring-deficit hypothesis". Trends Cogn. Sci. (Regul. Ed.) 11 (11): 458–65. doi:10.1016/j.tics.2007.08.015. PMID 17983834.
- Chung KK, Ho CS, Chan DW, Tsang SM, Lee SH (February 2010). "Cognitive profiles of Chinese adolescents with dyslexia". Dyslexia 16 (1): 2–23. doi:10.1002/dys.392. PMID 19544588.
- Handler SM, Fierson WM, Section on Ophthalmology et al. (March 2011). "Learning disabilities, dyslexia, and vision". Pediatrics 127 (3): e818–56. doi:10.1542/peds.2010-3670. PMID 21357342.
- Human Voice Recognition Science Magazine July 2011
- McCandliss BD, Noble KG (2003). "The development of reading impairment: a cognitive neuroscience model". Ment Retard Dev Disabil Res Rev 9 (3): 196–204. doi:10.1002/mrdd.10080. PMID 12953299.
- Birsh, Judith R. (2005). "Research and reading disability". In Judith R. Birsh. Multisensory Teaching of Basic Language Skills. Baltimore, Maryland: Paul H. Brookes Publishing. p. 8. ISBN 978-1-55766-676-5. OCLC 234335596.
- "What Is Dyslexia?". AVKO Education Research Foundation. Retrieved 5 July 2010.
- "Developmental dyslexia in adults: a research review". National Research and Development Centre for Adult Literacy and Numeracy. 1 May 2004. pp. *133–147. Retrieved 13 May 2009.
- Brazeau-Ward, Louise (2001). Dyslexia and the University. Canada: Canadian Dyslexia Centre. pp. 1–3. ISBN 1-894964-71-3.
- Castles A, Coltheart M (May 1993). "Varieties of developmental dyslexia". Cognition 47 (2): 149–80. doi:10.1016/0010-0277(93)90003-E. PMID 8324999.
- Habib M (December 2000). "The neurological basis of developmental dyslexia: an overview and working hypothesis". Brain 123 (12): 2373–99. doi:10.1093/brain/123.12.2373. PMID 11099442.
- Boder E (October 1973). "Developmental dyslexia: a diagnostic approach based on three atypical reading-spelling patterns". Developmental Medicine and Child Neurology 15 (5): 663–87. doi:10.1111/j.1469-8749.1973.tb05180.x. PMID 4765237.
- Galaburda AM, Cestnick L (February 2003). "[Developmental dyslexia]". Rev Neurol (in Spanish; Castilian). 36 Suppl 1: S3–9. PMID 12599096.
- Cestnick Laurie, Coltheart M, (March 1999). "The Relationship Between Language-Processing and Visual-Processing Deficits in Developmental Dyslexia". Cognition 71 (3): 231–55. doi:10.1016/S0010-0277(99)00023-2. PMID 10476605.
- Cestnick Laurie, Jerger James, (October 2000). "Auditory temporal processing and lexical/nonlexical reading in developmental dyslexics". Journal of American Academy of Audiology 11 (9): 501–513. PMID 11057735.
- Cestnick Laurie (August 2001). "Cross-modality temporal processing deficits in developmental phonological dyslexics". Brain and Cognition 46 (3): 319–325. doi:10.1006/brcg.2000.1273. PMID 11487282.
- Davis, R. D. (with E. M. Braun). (1994). The gift of dyslexia. Burlingame, CA: Ability Workshop Press.
- Huc-Chabrolle M, Barthez MA, Tripi G, Barthélémy C, Bonnet-Brilhault F (April 2010). "[Psychocognitive and psychiatric disorders associated with developmental dyslexia: A clinical and scientific issue]". Encephale (in French) 36 (2): 172–9. doi:10.1016/j.encep.2009.02.005. PMID 20434636.
- Schott GD, Schott JM (December 2004). "Mirror writing, left-handedness, and leftward scripts". Arch. Neurol. 61 (12): 1849–51. doi:10.1001/archneur.61.12.1849. PMID 15596604.
- Schott GD (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.
- Cherry RS, Kruger B (April 1983). "Selective auditory attention abilities of learning disabled and normal achieving children". Journal of Learning Disabilities 16 (4): 202–5. doi:10.1177/002221948301600405. PMID 6864110.
- Willcutt, E.G. & Pennington, B.F. (2000). "Comorbidity of reading disability and attention-deficit/ hyperactivity disorder: Differences by gender and subtype". Journal of Learning Disabilities 33: 179–191.
- Willcutt, E.G. & Pennington, B.F. (2010). "Etiology and neuropsychology of comorbidity between RD and ADHD: The case for multiple-deficit models". Cortex 46: 1345–1361.
- Facoetti, Andrea; Nicola Corradi, Milena Ruffino, Simone Gori, Marco Zorzi (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.
- 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.
- Ho CS-H Lai DN-Ch (1999). "Naming-speed deficits and phonological memory deficits in Chinese developmental dyslexia". J Learn Disabil 2: 173–86. doi:10.1016/S1041-6080(00)80004-7.
- Kobayashi, MS, Haynes, CW, MacAruso, P, Hook, PE, Kato, J (June 2005). "Effects of mora deletion, nonword repetition, rapid naming, and visual search performance on beginning reading in Japanese". Annals of dyslexia 55 (1): 105–28. doi:10.1007/s11881-005-0006-7. PMID 16107782.
- Jones, MW, Branigan, HP, Kelly, ML. (2009). "Dyslexic and nondyslexic reading fluency: Rapid automatized naming and the importance of continuous lists". Psychonomic Bulletin & Review 16 (3): 567–572. doi:10.3758/PBR.16.3.567.
- 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.
- "What is Dyslexia?". The National Center for Learning Disabilities. 5 March 2009. Retrieved 9 July 2012.
- 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.
- Berkhan, O. (February 1885). "Über die Störung der Schriftsprache bei Halbidioten und ihre Ähnlichkeit mit dem Stammeln" [About the disorder of written language of half-idiots and their similarity with dislaia]. Archiv für Psychiatrie und Nervenkrankenheiten 16 (1): 78–86. doi:10.1007/BF02227300.
- Wagner, Rudolph (January 1973). "Rudolf Berlin: Originator of the term dyslexia". Annals of Dyslexia 23 (1): 57–63. doi:10.1007/BF02653841.
- Berlin R (1884). "Über Dyslexie" [About dyslexia]. Archiv fur Psychiatrie 15: 276–278.
- Henry, Marcia K. (2005). "The history and structure of the English language". In Judith R. Birsh. Multisensory Teaching of Basic Language Skills. Baltimore, Maryland: Paul H. Brookes Publishing. p. 154. ISBN 978-1-55766-676-5. OCLC 234335596.
- 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.
- Siok WT, Niu Z, Jin Z, Perfetti CA, Tan LH (April 2008). "A structural-functional basis for dyslexia in the cortex of Chinese readers". Proc. Natl. Acad. Sci. U.S.A. 105 (14): 5561–6. doi:10.1073/pnas.0801750105. PMC 2291101. PMID 18391194.
- Wydell TN, Butterworth B (April 1999). "A case study of an English-Japanese bilingual with monolingual dyslexia". Cognition 70 (3): 273–305. doi:10.1016/S0010-0277(99)00016-5. PMID 10384738.
- David Crystal. 1987. The Cambridge encyclopedia of language. Cambridge: Cambridge University Press
- Ziegler, J.C.; Perry, C.; Ma-Wtatt, A.; Ladner, D.; Schulte-Korne, G. (2003). "Developmental dyslexia in different languages: Language specific or universal?". Journal of Experimental Child Psychology 86 (3): 169–193. doi:10.1016/S0022-0965(03)00139-5. PMID 14559203.
- Nicolson RI, Fawcett AJ (September 2009). "Dyslexia, dysgraphia, procedural learning and the cerebellum". Cortex 47 (1): 117–27. doi:10.1016/j.cortex.2009.08.016. PMID 19818437.
- Ramus F, Pidgeon E, Frith U (July 2003). "The relationship between motor control and phonology in dyslexic children". Journal of Child Psychology and Psychiatry, and Allied Disciplines 44 (5): 712–22. doi:10.1111/1469-7610.00157. PMID 12831115.
- Rochelle KS, Witton C, Talcott JB (February 2009). "Symptoms of hyperactivity and inattention can mediate deficits of postural stability in developmental dyslexia". Experimental Brain Research 192 (4): 627–33. doi:10.1007/s00221-008-1568-5. PMID 18830588.
- Eva Germano, Antonella Gagliano, Paolo Curatolo (2010). "Comorbidity of ADHD and Dyslexia". Developmental Neuropsychology 35 (5): 475–493. doi:10.1080/87565641.2010.494748. PMID 20721770.
- Moore DR (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.
- Veuillet E, Magnan A, Ecalle J, Thai-Van H, Collet L (November 2007). "Auditory processing disorder in children with reading disabilities: effect of audiovisual training". Brain 130 (Pt 11): 2915–28. doi:10.1093/brain/awm235. PMID 17921181.
- Ramus F (April 2003). "Developmental dyslexia: specific phonological deficit or general sensorimotor dysfunction?". Current Opinion in Neurobiology 13 (2): 212–8. doi:10.1016/S0959-4388(03)00035-7. PMID 12744976.
- Moncrieff, Deborah (2 February 2004). "Temporal Processing Deficits in Children with Dyslexia". speechpathology.com (speechpathology.com). Retrieved 13 May 2009.
- Moncrieff, Deborah (23 September 2002). "Auditory Processing Disorders and Dyslexic Children". audiologyonline.com (audiologyonline.com). Retrieved 13 May 2009.
- Schuele CM (2004). "The impact of developmental speech and language impairments on the acquisition of literacy skills". Ment Retard Dev Disabil Res Rev 10 (3): 176–83. doi:10.1002/mrdd.20014. PMID 15611989.
- Peterson RL, McGrath LM, Smith SD, Pennington BF (June 2007). "Neuropsychology and genetics of speech, language, and literacy disorders". Pediatr. Clin. North Am. 54 (3): 543–61, vii. doi:10.1016/j.pcl.2007.02.009. PMID 17543909.
- Levinson, H.N. (1980). A Solution to the Riddle – Dyslexia. Springer-Verlag. pp. 25–71. ISBN 978-1-4613-9774-8.
- Levinson, H. N. (1988). The cerebellar-vestibular basis of learning disabilities in children, adolescents and adults: Hypothesis and study, perceptual motor skills 67. pp. 983–1006.
- Leiner, H.; Leiner, R.; Dow (1991). "The human cerebro-cerebellar system: Its computing, cognitive, and language skills". Behavioral Brain Research 44 (2): 113–28.
- Snider, R.S.; Stowell, A. (1944). "Receiving areas of the tactile, auditory, and visual systems in the cerebellum". Journal of Neurophysiology 7: 331–357.
- Frank, J.; Levinson, H. N. (1977). Academic Therapy Publications 12 (4): 411–425.
- Levinson, H. N. (1991). "Dramatic favorable responses of children with learning disabilities or dyslexia and attention deficit disorder to antimotion sickness medications: Four case reports". Perceptual Motor Skills 71: 67–82.
- Ayres, A. J. (1978). "Learning disabilities and the vestibular system". Journal of Learning Disabilities 11 (1): 30–41.
- Solan, O. D.; Shelley-Tremblay, Harold A.; Larson, John; Steven, D. (2007). "Vestibular function, sensory integration, and balance anomalies: A brief literature review". Review Optom Vis Dev 38 (1): 1–5.
- Eccles, J.C. (1986). "Learning in the motor system". Progress in Brain Research 64: 3–17.
- Frank, J.; Levinson, H. N. (1976). Academic Therapy 12: 5–27.
- Jody Swarbrick; Abigail Marshall (10 September 2004). The Everything Parent's Guide To Children With Dyslexia: All You Need To Ensure Your Child's Success. Everything Books. pp. 93–. ISBN 978-1-59337-135-7. Retrieved 10 April 2012.
- 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.
- Thomas Richard Miles (15 January 2004). Dyslexia and stress. Whurr. ISBN 978-1-86156-383-5. Retrieved 10 April 2012.
- 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.
- 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.
- 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.
- Chenault B, Thomson J, Abbott RD, Berninger VW (2006). "Effects of prior attention training on child dyslexics' response to composition instruction". Developmental Neuropsychology 29 (1): 243–60. doi:10.1207/s15326942dn2901_12. PMID 16390296.
- Berkhan O (1917). "Über die Wortblindheit, ein Stammeln im Sprechen und Schreiben, ein Fehl im Lesen". Neurol. Centralbl. 28.[page needed]
- Wagner, Rudolph (January, 1973). "Rudolf Berlin: Originator of the term dyslexia". Annals of Dyslexia 23 (1): 57–63. doi:10.1007/BF02653841.
- Snowling MJ (November 1996). "Dyslexia: a hundred years on". BMJ 313 (7065): 1096–7. doi:10.1136/bmj.313.7065.1096. PMC 2352421. PMID 8916687.
- "Dyslexia assessment in Arabic. Gad Elbeheri. 2006; Journal of Research in Special Educational Needs – Wiley InterScience".
- Aboudan, R, et aL. (2011). "Dyslexia in the United Arab Emirates University–a study of prevalence in English and Arabic". International Journal of English Linguistics 1: 64–72.
- Smythe I, Everatt J, Al-Menaye N et al. (August 2008). "Predictors of word-level literacy amongst Grade 3 children in five diverse languages". Dyslexia 14 (3): 170–87. doi:10.1002/dys.369. PMID 18697190.
- Friedmann N, Rahamim E (September 2007). "Developmental letter position dyslexia". J Neuropsychol 1 (Pt 2): 201–36. doi:10.1348/174866407X204227. PMID 19331018.
- Schiff R, Raveh M (May 2007). "Deficient morphological processing in adults with developmental dyslexia: another barrier to efficient word recognition?". Dyslexia 13 (2): 110–29. doi:10.1002/dys.322. PMID 17557687.
- Cao F, Bitan T, Chou TL, Burman DD, Booth JR (October 2006). "Deficient orthographic and phonological representations in children with dyslexia revealed by brain activation patterns". Journal of Child Psychology and Psychiatry, and Allied Disciplines 47 (10): 1041–50. doi:10.1111/j.1469-7610.2006.01684.x. PMC 2617739. PMID 17073983.
- Chertkow H, Murtha S (1997). "PET activation and language". Clinical Neuroscience 4 (2): 78–86. PMID 9059757.
- McCrory E, Frith U, Brunswick N, Price C (September 2000). "Abnormal functional activation during a simple word repetition task: A PET study of adult dyslexics". Journal of Cognitive Neuroscience 12 (5): 753–62. doi:10.1162/089892900562570. PMID 11054918.
- Schmahmann, J. D.; Sherman, J. C. (1998). "The cerebellar cognitive affective syndrome". Brain 121: 561–79.
- Rae, C.; Harasty, J. H.; Djendrowskji, J.; Talcott, J.; Simpson, J.; Blamire, A.; Dixon, R. M.; Lee, M.; Thompson, C. H.; Styles, P.; Richardson, A. J.; Stein, J. F. (2001). 5th BDA International Conference. pp. 1–10.
- Allen, G.; Buxton, R. B.; Wong, E. C.; Courchesne, E. (28 March 1997). "Attentional activation of the cerebellum independent of motor involvement". Science 275 (5308): 1940–1943.
- Galaburda AM, Kemper TL (August 1979). "Cytoarchitectonic abnormalities in developmental dyslexia: A case study". Annals of Neurology 6 (2): 94–100. doi:10.1002/ana.410060203. PMID 496415.
- Galaburda, A.M.; Sherman, G.F.; Rosen, G.D.; Aboitiz, F.; Geschwind, N. (August 1985). "Developmental dyslexia: four consecutive patients with cortical abnormalities". Annals of Neurology 18: 222–223. doi:10.1002/ana.410180210. PMID 4037763.
- Cohen M, Campbell R, Yaghmai F (June 1989). "Neuropathological abnormalities in developmental dysphasia". Annals of Neurology 25 (6): 567–70. doi:10.1002/ana.410250607. PMID 2472772.
- Levinson, H.N. (2008). Revised and updated smart but feeling dumb new understanding and dramatic treatment for dyslexia (LD/ADD). Stonebridge Publishing, Ltd. pp. 170–173. ISBN 978-0-615-15276-9.
- Levinson, H.N. (1994). A Scientific Watergate – Dyslexia. Stonebridge Publishing. pp. 347–349. ISBN 0-9639303-0-3.
- Livingstone, M.S.; Drislane, F.W.; Rosen, G.D.; Galaburda, A.M. (1991). "Physiological and anatomical evidence of a magnocellular defect in developmental dyslexia". Proceedings of the National Academy of Sciences of the USA 88: 7943–7947.
- Rae, C., Lee, M.A., Dixon, R.M., Blamire, Thompson, C.H., Styles, P., Talcott, J., Richardson, A.J., and Stein, J.F. (1998). "Metabolic abnormalities in developmental dyslexia detected by H Magnetic resonance spectroscopy". The Lancet 351 (119): 1893–1952.
- Frank, J.; Levinson, H.N. (1973). "Dysmetric Dyslexia and Dyspraxia: Hypothesis and study". Journal of American Academy of Child Psychiatry 12: 690–701.
- De Quiros, J.B. (1976). "Diagnosis of vestibular disorders in the learning disabled". Journal of Learning Disabilities 9: 39–58.
- Frank, J.; Levinson, H.N. (1975-1976). "Dysmetric dyslexia and dyspraxia: Synopsis of a continuing research project". Academic Therapy 11: 133–143.
- Levinson, H.N. (1980). A Solution to the Riddle Dyslexia. Springer-Verlag. pp. 96–99. ISBN 3-540-90515-4.
- Rahko, Tapani (2003). "Alleviating dyslexia by treating benign positional vertigo and eye movement disturbances, saccades". Finnish Medical Journal 39: 3883–3886.
- 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.
- Taylor J, Roehrig AD, Soden Hensler B, Connor CM, Schatschneider C. (April 2010). "Teacher quality moderates the genetic effects on early reading on reading disability". Science 328 (5977): 512–14. doi:10.1126/science.1186149. PMC 2905841. PMID 20413504.
- Pennington, B.F., McGrath, L.M., Rosenberg, J., Barnard, H., Smith, S.D., Munroe, H.B., Willcutt, E.G., Friend, A., DeFries, J.C., & Olson, R.K. (2009). "Gene x Environment Interactions in Reading Disability and Attention-Deficit/Hyperactivity Disorder". Developmental Psychology 45 (1): 77–89. doi:10.1037/a0014549. PMC 2743891. PMID 19209992.
- Pennington, BF; McGrath LM, Rosenberg J, Barnard H, Smith SD, Willcutt EG, Friend A, Defries JC, Olson RK. (January 2009). "Gene × Environment Interactions in Reading Disability and Attention-Deficit/Hyperactivity Disorder". Dev Psychol. 45 (1): 77–89. doi:10.1037/a0014549. PMC 2743891. PMID 19209992.
- Roth, TL; Roth ED, Sweatt JD (September 2010). "Epigenetic regulation of genes in learning and memory". Essays Biochem 48 (1): 263–74. doi:10.1042/bse0480263. PMID 20822498.
- International Dyslexia Association
- Dyslexia Action (UK)
- British Dyslexia Association
- Dyslexia Research Trust
- Learning Ally, formerly Recording for the Blind & Dyslexic
- The Brain Foundation.Singapore
- The National Center for Learning Disabilities
- Dyslexia Foundation of New Zealand
- International Dyslexia Association
- Center for the Assessment and Remediation of Reading Difficulties