What Is Dyslexia: Signs, Causes And Treatment

Dyslexia is a complex neurodevelopmental disorder that makes it difficult for individuals to read, spell, write, and learn. It is a life-long condition that can be effectively managed with special education programs. The first step to treating dyslexia is identifying its signs and symptoms and seeking professional help.

What Is Dyslexia?

Dyslexia is a learning disorder in which a person has difficulty in reading, identifying speech sounds, and recognizing letters, symbols, etc. The word “dyslexia” is derived from two Greek words: “dys” meaning inadequate or lack of and “lexicon” meaning word. According to a 2012 study ¹, “Dyslexia thus means problems learning how to read words and deal with language in print.”

However, recent research has moved beyond seeing dyslexia as a simple reading disorder and attributed it to be a neurodevelopmental condition ² in the brain that causes “difficulty in literacy acquisition, cognitive processes and discrepancies in educational outcomes.” Today, it is considered one of the many neuropsychological and neurobiological disorders ³ in the spectrum of learning disabilities (LDs) that affect a person’s ability to read, learn, or speak fluently. It is also distinguished from mental illnesses and reading difficulties caused by vision or hearing problems or by poor teaching methods or inadequate learning opportunities.

Studies ⁴ show that people with dyslexia have damaged and disoriented ⁵ visual analysis systems and suffer from major changes in the brain’s structures and functions related to learning and language processing. Because of this, they often have difficulty in reading, writing, learning new things, or speaking. They often do not recognize or are confused ⁶ by letters, symbols, signs, words, or sounds. They face difficulties in processing grammar and spellings or understanding how semantics or phonetics work in sentence structures.

Writings appear blurry to them, because of which they often misread words, write them wrongly, or change their meanings. Dyslexic people also face problems related to attention deficiency, hyperactivity, and touch. It is also commonly thought that dyslexic people have low or below average intelligence, but research ⁷ shows that they have average or above average intelligence and are often blessed with skills like critical thinking, problem solving, etc.

Understanding Dyslexia

Dyslexia is usually a life-long condition, with genetic roots ⁸ or it can be induced by age ⁹ or physical injuries ¹⁰ to the brain. The early signs of dyslexia often occur in childhood, especially in the pre-schooling years, but because of its wide bevy of symptoms in younger population groups like children who cannot properly convey the difficulties they face, dyslexia goes undiagnosed and untreated. Even if it is diagnosed in later years or adulthood, treatment may not have as effective outcomes as early treatment.

There is no established set of causes of dyslexia and research is still underway to properly understand the disorder. However, experts agree on the negative long-term impact of dyslexia, especially given that it cannot be completely cured.

The poor learning abilities caused by dyslexia interfere with the dyslexic person’s quality of life, often leading to social and professional problems. They find it difficult to perform publicly and often suffer from a fear of schools, or activities related to learning. Dyslexia is also linked to high rates of depression, anxiety, social anxiety, and suicide. To prevent these complexities in later life, it is recommended that dyslexia should be diagnosed at the earliest opportunity ¹¹ and addressed with effective education programs, teaching methods, and support groups.

Read More About Social Anxiety Disorder (SAD) Here

What Are The Different Types Of Dyslexia?

The symptoms and causes of dyslexia are too wide-ranging ¹² and heterogeneous and, in most cases, it is seen that if “relevant stimuli for a certain type of dyslexia are not detected during diagnosis”, that dyslexia is easily dismissed. Because of this, experts have grouped together several common types of dyslexia—based on the symptoms and causes—to increase the effectiveness of treatment. Some of these types are mentioned below –

1. Based On Causes

Based on causes, dyslexia can be categorized into the following types:

1. Developmental dyslexia

Developmental dyslexia is a genetic neuronal development present from birth that “impacts selectively on the ability to learn to read, leaving oral and non-verbal reasoning powers intact”. This dyslexia is more prevalent in left-handed males ¹³ and usually diminishes with age. It can be easily addressed by “remediation programmes tailored to each child’s particular, individual, pattern of needs”.

Developmental dyslexia can be categorized into the following types:

A. Primary dyslexia

If a person’s parents are dyslexic, his/her dyslexia is directly inherited ¹⁴. This is called primary dyslexia.

B. Secondary dyslexia

Secondary dyslexia is caused by problems in brain development during the early stages of pregnancy. This can happen in children whose parents have no history of dyslexia.

C. Peripheral dyslexia

A person suffering from this type of dyslexia usually has a damaged visual analysis system. Peripheral dyslexia can be divided into three subtypes:

Neglect dyslexia
Attentional dyslexia
Letter-by-letter reading dyslexia

D. Central dyslexia

One 2012 study says that, in people with central dyslexia, “processes beyond the visual analysis system are damaged, resulting in difficulties in comprehension and/or pronunciation of written words”. Central dyslexia is of different types, such as:

Non-semantic reading
Surface dyslexia
Phonological dyslexia
Deep dyslexia

2. Acquired Dyslexia/Alexia

A person, who could previously read, sometimes ‘acquires’ dyslexia if a brain injury, stroke, progressive illness, dementia, or a traumatic experience impacts the brain areas associated with learning and processing languages. This is also known as alexia.

2. Based On Symptoms

Dyslexia is a disorder with selective deficits that affect our reading abilities or language processing skills. While alexia is only dyslexia with a known cause and, sometimes, definite manifestations, developmental dyslexias are quite a different matter. In it, the selective deficits and their symptoms are varied, because of which experts find it convenient to categorize it into the following types:

1. Letter position dyslexia

In this type of dyslexia, people can identify letters correctly, but they fail to understand the order of the letters ¹⁵ within a given word. They perform well when it comes to speech production, but they are poor performers ¹⁶ in writing tasks.

For instance, they will read the word “dairy” as “diary”.

2. Attentional dyslexia

In this type of dyslexia, people tend to misplace ¹⁷ the different letters in a given word, even though they can correctly identify and keep the original relative position of letters within the word.

For instance, they will read “lion’s den” as “dion’s len”.

3. Letter identity dyslexia

People with this type of dyslexia fail to identify letters ¹⁸ and create abstract identity of letters from their visual form, as “they cannot name a letter, identify a written letter according to its name or sound, or match letters in different cases.”

For instance, they will find it difficult to read words like “ASAP” or “The Oxford Wine Company”.

4. Neglect dyslexia

People with neglect dyslexia fail to read a side of a word ¹⁹, typically the left side of a word. They substitute or add letters in words they cannot fully read, and end up changing the meaning of a word.

For instance, for them, the word “rice” becomes “lice” or “mice”.

5. Visual dyslexia

In people with visual dyslexia, the brain doesn’t get the complete picture ²⁰ of what their eyes see, because of which they find it difficult to identify letters. They mostly replace letters within words or within sentences.

For instance, a written page will appear blurry and out of focus to them, making the words incomprehensible.

6. Surface dyslexia

People with surface dyslexia cannot recognize ²¹ similar words.

For instance, people with this dyslexia will fail to understand the difference between “witch”, “which”, and “wich”.

7. Phonological dyslexia

The most common type ²² of dyslexia, phonological dyslexia prevents people ²³ from matching sounds with symbols and understanding the sounds of language.

People with this dyslexia often find it difficult to speak and/or pronounce words correctly.

8. Vowel letter dyslexia

People with this dyslexia often “omit, substitute, transpose, and add vowel letters” in a given word ²⁴.

For example, they process the word “cat” as “coat” or “cot”.

9. Deep dyslexia

People with deep dyslexia often process words ²⁵ with semantic, morphological, and visual errors.

For instance, for them, the word “smiles” becomes “smiling”.

What Are The Symptoms Of Dyslexia?

The symptoms of dyslexia are often varied across the dyslexic spectrum. But people afflicted with it often show the following dyslexia signs and symptoms:

Difficulty in reading
Difficulty in learning new words
Difficulty in recognizing letters or symbols
Difficulty in rhyming words
Difficulty in processing grammar, spellings, or sentence structures
Lack of semantic or phonological awareness while processing languages
Misreading words and changing their meanings
Delayed speech development
Attention deficiency
Hyperactivity

What Causes Dyslexia?

Research is still underway when it comes to understanding the actual causes of dyslexia. Sometimes, it is viewed as a neurological disorder; at other times, it is a reading, learning, or a visual disorder. However, decades of scholarly research and medical practice has established that dyslexia is caused by an interaction of genetic, biological, and environmental factors.

1. Genetic factors

Like other neurodevelopmental disorders, dyslexia is heritable and/or induced during pregnancy, with life-long conditions and early onset. Research attributes the heritable causes of dyslexia to:

A family history of dyslexia
A family history of other learning/neurodevelopmental disorders
Premature birth
Low birth weight
Physical injury to the fetus during pregnancy
Exposure to nicotine, drugs, alcohol during pregnancy
Exposure to infections that alter fetal brain development during pregnancy

2. Biological Factors

One 2022 study ²⁶ says that people with both developmental dyslexia and alexia share a damaged visual analysis system and major changes in the brain’s structures and functions related to learning, such as:

Cerebellum
Cerebral cortex
Reduced gray matter
Frontal and temporal regions

3. Environmental Factors

According to a 2009 study ²⁷, “Factors related to poverty and the family’s orientation to literacy represent risk factors for dyslexia.” Not only dyslexic children, but also children who find it difficult to learn can develop dyslexia-like signs in environments that are hostile to learning. Studies ²⁸ further link the causes of dyslexia to:

The impact of language on poverty
Insufficient learning opportunities
Poor literacy-related activities
Insufficient teaching methods

Dyslexia Across Ages

Dyslexia is usually present from birth and the early signs of dyslexia occur in childhood and at pre-schooling years when children usually start learning. In younger years, dyslexia causes common learning problems. But if this is unaddressed, dyslexia grows on to have a more severe impact on people in adulthood, interfering with their social and professional abilities and their quality of life.

1. Dyslexia In Children

According to a 2022 study, developmental dyslexia and its different types are the most common type of dyslexia in children, making them “have a difficult time learning to decode words”. A 2012 study shows that about 10–16% of children across the world have some form of dyslexia and are in need of special education programs.

The signs of dyslexia in kids usually involve slow learning, impaired speech development, and problems related to recognizing letters, signs, numbers, symbols, etc. Dyslexic children often suffer from a fear of learning and schools, low self-esteem, and a fear of being punished or criticized for mistakes related to learning. They are also the ones with poor school performance, bullying experiences, and poor social adjustment. Another 2010 study ²⁹ shows that 40% to 60% of dyslexic children have psychological disorders, including anxiety, depression, social phobia, suicidal thoughts, etc.

Studies also show that the early signs of dyslexia are often coexisting with other learning disorders, such as:

Attention deficit disorder (ADD)
Attention deficit hyperactivity disorder (ADHD ³⁰ )
Developmental language disorders
Somatic dysfunction ³¹
Dysgraphia ³²
Auditory processing disorder
Developmental coordination disorder ³³

Read More About Dysgraphia Here

2. Dyslexia In Adults

In adults, dyslexia can be genetic or acquired and the disorder negatively impacts their social life, professional reputation, mental health, and their quality of life.

Apart from the most common markers of dyslexia—reading and writing problems—dyslexic adults suffer from memory problems, clumsiness, and poor social and organizational skills. They also suffer from low self-esteem and face difficulties in public speaking or reading or in mere tasks like writing a report, making a planner, etc. One 2014 study ³⁴ found that signs of dyslexia in adults often involve cognitive deficits like poor short-term memory, poor hand-eye coordination, depressive moods, attention problems, etc.

How Is Dyslexia Diagnosed?

The International Classification of Diseases (ICD-10) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) both recognize dyslexia as a “brain-based difficulty in reading” and have laid down the criteria for its diagnosis. These psychiatric manuals also recommend the differential diagnosis of dyslexia from the core symptoms of similar disorders, because of which how dyslexia is diagnosed takes into consideration factors ³⁵ like:

Isolated reading disorder
Isolated spelling disorder
Vision impairment
Hearing impairment
Psychiatric disorders (ADD, ADHD, anxiety, depression, etc.)
Children’s cognitive disabilities (like poor memory, speech difficulties, learning disabilities, etc.)
Chronic diseases (like diabetes mellitus, etc.)
Negative psychosocial factors (like school history, bullying, poor social life, etc.)
Negative psychosocial environments (like dysfunctional families, inadequate schooling facilities, etc.)
Toxin exposure (like lead poisoning, etc.)

Read More About Bullying Here

How To Diagnose Dyslexia With Tests

A large number of diagnostic tests for dyslexia is available, and one 2012 study recommends that such tests can be performed by “teachers, specialists, doctors, nurses, psychologists, and others who may be involved in care and development of the affected child.”

Dyslexia is often screened by:

Physical examination (like MRI scans, blood tests, etc.) that look for visual, hearing, or other physical disabilities in dyslexic people
Intelligence tests (like IG tests, language tests, reading tests, etc.)
Clinical screening tools (like Wechsler Intelligence Scale for Children [WISC-IV], Minnesota Mechanical Assembly Test, Stanford Intelligence Test, etc.)

What Is The Treatment For Dyslexia?

In spite of being a common and life-long condition, there is no prescribed treatment process for dyslexia. But its early and timely diagnosis, coupled with “remediation programs tailored to each [person’s] particular, individual, pattern of needs”, can help dyslexic people manage their learning disabilities. One 2010 study sums up the two parts of dyslexia treatment:

Treatment of core problems with reading and spelling
Treatment of any concurrent psychological disorders

According to a 2012 study, early interventions of dyslexia often focus on vocabulary, comprehension, and necessary skills such as phonics. As dyslexic people progress through their age and education, “the [later] intervention will move to improve understanding of word meanings, improved comprehension, more challenging reading, and strategies to excel.”

These interventions are often carried out—via child support programs, special learning centers, reading programs, group education systems, etc. using strategies such as:

Individualized education programmes ³⁶
Multisensory teaching methods ³⁷
Assisted learning techniques ³⁸, like text-to-speech educational devices, audio books, etc.
Use of different methods ³⁹, such as word games, paired reading, cued spelling, and peer tutoring
Class-wide approaches ⁴⁰, such as policy framework and whole school screening
Counseling ⁴¹, art therapy ⁴², and intensive training programs ⁴³ with “dyslexia therapists”

Recent research ⁴⁴ has tried to incorporate medication use in dyslexia treatment for severe cases. For instance, they have tried to treat dyslexic people with drug treatment for ADHD ⁴⁵ and movement disorders ⁴⁶. But, these experimental treatments have not yielded successful results ⁴⁷.

How Can You Help Someone With Dyslexia?

Dyslexia is a life-long neurodevelopmental condition, accompanied by learning difficulties, speech disorder, and other cognitive disorders. Dyslexia treatment is also a complex, lengthy, and expensive process—because of which people associated with dyslexic children and adults should educate themselves about the disorder, its causes, and its treatment.

To help someone with dyslexia, consider the following suggestions:

Look out for the signs and symptoms of dyslexia
Help the person get screened for dyslexia with diagnostic tests
Research the available education programs and support groups for dyslexia in your locality and enroll them in such programs
Encourage them to read more, limit their screen time, and their socialization efforts
Communicate with them openly and supportively
Check on their progress and encourage them in their day-to-day learning activities
Support them in their attempts to overcome learning difficulties with patience, kindness, love, and empathy

Takeaway

Dyslexia is a complex neurodevelopmental disorder that makes it difficult for individuals to read, write, and learn. It also impacts their social, economic, and professional outcomes in life. Living with dyslexia can be difficult, but if it is diagnosed early on and supported with the right education programs—individuals with dyslexia can lead a healthy and normal life.

Dyslexia At A Glance

Dyslexia is a complex neurodevelopmental condition that causes learning disorders.
It is caused by a number of genetic, biological, and environmental factors.
The symptoms of dyslexia are poor reading and learning abilities, slow speech, attention problems, etc.
Dyslexic people are often prone to low self-esteem, depressive and anxiety disorders, and social anxiety.
Dyslexia is a life-long condition that cannot be cured.
It can be easily managed by special learning and support programs.

Frequently Asked Questions (FAQs)

1. Who are some famous people with dyslexia?

Steve Jobs, Tom Cruise, Hans Christian Anderson, Thomas Alva Edison, Albert Einstein, Stephen Hawking, Leonardo da Vinci, Pablo Picasso, Abraham Lincoln, Salma Hayek, and Keira Knightley are some of the most famous people with dyslexia.

2. Is dyslexia a mental illness?

Dyslexia is a neurological disorder that causes common learning problems. It is currently not considered as a mental illness, though 30 years ago, it was treated by psychiatric processes.

3. Are Dyslexics highly intelligent?

Most people with dyslexia are average or above-average intelligent. They are also very innovative thinkers and capable problem solvers.

4. Can dyslexia be cured?

Dyslexia is a life-long problem and there is no cure for the underlying brain and neurological abnormalities that cause it. However, with the right teaching programs and methods and other forms of treatment, it can be easily managed.

References:

1
Al-Shidhani, T. A., & Arora, V. (2012). Understanding Dyslexia in Children through Human Development Theories. Sultan Qaboos University medical journal, 12(3), 286–294. https://doi.org/10.12816/0003141
2
A revised discrepancy method for identifying dyslexia. (2020, March 5). SpringerLink. https://link.springer.com/article/10.1007/s40817-020-00079-2
3
Snowling, M. J., Hulme, C., & Nation, K. (2020). Defining and understanding dyslexia: past, present and future. Oxford review of education, 46(4), 501–513. https://doi.org/10.1080/03054985.2020.1765756
4
Siegel L. S. (2006). Perspectives on dyslexia. Paediatrics & child health, 11(9), 581–587. https://doi.org/10.1093/pch/11.9.581
5
Mascheretti, S., De Luca, A., Trezzi, V., Peruzzo, D., Nordio, A., Marino, C., & Arrigoni, F. (2017). Neurogenetics of developmental dyslexia: from genes to behavior through brain neuroimaging and cognitive and sensorial mechanisms. Translational psychiatry, 7(1), e987. https://doi.org/10.1038/tp.2016.240
6
Siegel L. S. (2006). Perspectives on dyslexia. Paediatrics & child health, 11(9), 581–587. https://doi.org/10.1093/pch/11.9.581
7
Knight C. (2018). What is dyslexia? An exploration of the relationship between teachers’ understandings of dyslexia and their training experiences. Dyslexia (Chichester, England), 24(3), 207–219. https://doi.org/10.1002/dys.1593
8
Schumacher, J., Hoffmann, P., Schmäl, C., Schulte-Körne, G., & Nöthen, M. M. (2007). Genetics of dyslexia: the evolving landscape. Journal of medical genetics, 44(5), 289–297. https://doi.org/10.1136/jmg.2006.046516
9
D Barbosa AC, Emmady PD. Alexia. [Updated 2021 Nov 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557669/
10
Starrfelt, R., & Shallice, T. (2014). What’s in a name? The characterization of pure alexia. Cognitive neuropsychology, 31(5-6), 367–377. https://doi.org/10.1080/02643294.2014.924226
11
Snowling M. J. (2013). Early identification and interventions for dyslexia: a contemporary view. Journal of research in special educational needs : JORSEN, 13(1), 7–14. https://doi.org/10.1111/j.1471-3802.2012.01262.x
12
Zoubrinetzky, R., Bielle, F., & Valdois, S. (2014). New insights on developmental dyslexia subtypes: heterogeneity of mixed reading profiles. PloS one, 9(6), e99337. https://doi.org/10.1371/journal.pone.0099337
13
Tønnessen, F. E., Løkken, A., Høien, T., & Lundberg, I. (1993). Dyslexia, left-handedness, and immune disorders. Archives of neurology, 50(4), 411–416. https://doi.org/10.1001/archneur.1993.00540040063016
14
Galaburda, A. M., & Cestnick, L. (2003). Dislexia del desarrollo [Developmental dyslexia]. Revista de neurologia, 36 Suppl 1, S3–S9.
15
Friedmann, N., & Gvion, A. (2001). Letter position dyslexia. Cognitive neuropsychology, 18(8), 673–696. https://doi.org/10.1080/02643290143000051
16
Reilhac, C., Jucla, M., Iannuzzi, S., Valdois, S., & Démonet, J. F. (2012). Effect of orthographic processes on letter identity and letter-position encoding in dyslexic children. Frontiers in psychology, 3, 154. https://doi.org/10.3389/fpsyg.2012.00154
17
Lewandowska, M., Milner, R., Ganc, M., Włodarczyk, E., & Skarżyński, H. (2014). Attention dysfunction subtypes of developmental dyslexia. Medical science monitor : international medical journal of experimental and clinical research, 20, 2256–2268. https://doi.org/10.12659/MSM.890969
18
Bigsby P. (1990). Abstract letter identities and developmental dyslexia. British journal of psychology (London, England : 1953), 81 ( Pt 2), 227–263. https://doi.org/10.1111/j.2044-8295.1990.tb02358.x
19
Vallar, G., Burani, C., & Arduino, L. S. (2010). Neglect dyslexia: a review of the neuropsychological literature. Experimental brain research, 206(2), 219–235. https://doi.org/10.1007/s00221-010-2386-0
20
Quercia, P., Feiss, L., & Michel, C. (2013). Developmental dyslexia and vision. Clinical ophthalmology (Auckland, N.Z.), 7, 869–881. https://doi.org/10.2147/OPTH.S41607
21
Wybrow, D. P., & Hanley, J. R. (2015). Surface developmental dyslexia is as prevalent as phonological dyslexia when appropriate control groups are employed. Cognitive neuropsychology, 32(1), 1–13. https://doi.org/10.1080/02643294.2014.998185
22
Rapcsak, S. Z., Beeson, P. M., Henry, M. L., Leyden, A., Kim, E., Rising, K., Andersen, S., & Cho, H. (2009). Phonological dyslexia and dysgraphia: cognitive mechanisms and neural substrates. Cortex; a journal devoted to the study of the nervous system and behavior, 45(5), 575–591. https://doi.org/10.1016/j.cortex.2008.04.006
23
Tanaka, H., Black, J. M., Hulme, C., Stanley, L. M., Kesler, S. R., Whitfield-Gabrieli, S., Reiss, A. L., Gabrieli, J. D., & Hoeft, F. (2011). The brain basis of the phonological deficit in dyslexia is independent of IQ. Psychological science, 22(11), 1442–1451. https://doi.org/10.1177/0956797611419521
24
Khentov-Kraus, L., & Friedmann, N. (2018). Vowel letter dyslexia. Cognitive neuropsychology, 35(5-6), 223–270. https://doi.org/10.1080/02643294.2018.1457517
25
Siegel L. S. (1985). Deep dyslexia in childhood?. Brain and language, 26(1), 16–27. https://doi.org/10.1016/0093-934x(85)90025-2
26
Remien K, Marwaha R. Dyslexia. [Updated 2022 Feb 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557668/
27
Fletcher J. M. (2009). Dyslexia: The evolution of a scientific concept. Journal of the International Neuropsychological Society : JINS, 15(4), 501–508. https://doi.org/10.1017/S1355617709090900
28
Werth R. (2019). What causes dyslexia? Identifying the causes and effective compensatory therapy. Restorative neurology and neuroscience, 37(6), 591–608. https://doi.org/10.3233/RNN-190939
29
Schulte-Körne G. (2010). The prevention, diagnosis, and treatment of dyslexia. Deutsches Arzteblatt international, 107(41), 718–27. https://doi.org/10.3238/arztebl.2010.0718
30
Germanò, E., Gagliano, A., & Curatolo, P. (2010). Comorbidity of ADHD and dyslexia. Developmental neuropsychology, 35(5), 475–493. https://doi.org/10.1080/87565641.2010.494748
31
Hendren, R. L., Haft, S. L., Black, J. M., White, N. C., & Hoeft, F. (2018). Recognizing Psychiatric Comorbidity With Reading Disorders. Frontiers in psychiatry, 9, 101. https://doi.org/10.3389/fpsyt.2018.00101
32
Hanley, J. R., Hastie, K., & Kay, J. (1992). Developmental surface dyslexia and dysgraphia: an orthographic processing impairment. The Quarterly journal of experimental psychology. A, Human experimental psychology, 44(2), 285–319. https://doi.org/10.1080/02724989243000046
33
Margari, L., Buttiglione, M., Craig, F., Cristella, A., de Giambattista, C., Matera, E., Operto, F., & Simone, M. (2013). Neuropsychopathological comorbidities in learning disorders. BMC neurology, 13, 198. https://doi.org/10.1186/1471-2377-13-198
34
Nergård-Nilssen, T., & Hulme, C. (2014). Developmental dyslexia in adults: behavioural manifestations and cognitive correlates. Dyslexia (Chichester, England), 20(3), 191–207. https://doi.org/10.1002/dys.1477
35
Hammill, D. D., & Allen, E. A. (2020). A revised discrepancy method for identifying dyslexia. Journal of Pediatric Neuropsychology, 6(1), 27-43. https://doi.org/10.1007/s40817-020-00079-2
36
Ziegler, J. C., Perry, C., & Zorzi, M. (2020). Learning to Read and Dyslexia: From Theory to Intervention Through Personalized Computational Models. Current directions in psychological science, 29(3), 293–300. https://doi.org/10.1177/0963721420915873
37
Kast, M., Meyer, M., Vögeli, C., Gross, M., & Jäncke, L. (2007). Computer-based multisensory learning in children with developmental dyslexia. Restorative neurology and neuroscience, 25(3-4), 355–369.
38
Galuschka, K., Ise, E., Krick, K., & Schulte-Körne, G. (2014). Effectiveness of treatment approaches for children and adolescents with reading disabilities: a meta-analysis of randomized controlled trials. PloS one, 9(2), e89900. https://doi.org/10.1371/journal.pone.0089900
39
Bull L. (2007). Sunflower therapy for children with specific learning difficulties (dyslexia): a randomised, controlled trial. Complementary therapies in clinical practice, 13(1), 15–24. https://doi.org/10.1016/j.ctcp.2006.07.003
40
Pino, M., & Mortari, L. (2014). The inclusion of students with dyslexia in higher education: a systematic review using narrative synthesis. Dyslexia (Chichester, England), 20(4), 346–369. https://doi.org/10.1002/dys.1484
41
Fahle, M., & Luberichs, J. (1995). Extension of a recent therapy for dyslexia. German journal of ophthalmology, 4(6), 350–354.
42
Keeney A. H. (1969). Medical diagnostics and conseling in dyslexia. The Medical clinics of North America, 53(5), 1123–1129.
43
Oakland, T., Black, J. L., Stanford, G., Nussbaum, N. L., & Balise, R. R. (1998). An evaluation of the dyslexia training program: a multisensory method for promoting reading in students with reading disabilities. Journal of learning disabilities, 31(2), 140–147. https://doi.org/10.1177/002221949803100204
44
Toffalini, E., Giofrè, D., Pastore, M., Carretti, B., Fraccadori, F., & Szűcs, D. (2021). Dyslexia treatment studies: A systematic review and suggestions on testing treatment efficacy with small effects and small samples. Behavior research methods, 53(5), 1954–1972. https://doi.org/10.3758/s13428-021-01549-x
45
Artigas-Pallarés J. (2009). Tratamiento farmacológico de la dislexia [Pharmacological treatment of dyslexia]. Revista de neurologia, 48(11), 585–591.
46
Wilsher, C., Atkins, G., & Manfield, P. (1979). Piracetam as an aid to learning in dyslexia. Preliminary report. Psychopharmacology, 65(1), 107–109. https://doi.org/10.1007/BF00491989
47
Wilsher, C. R., Bennett, D., Chase, C. H., Conners, C. K., DiIanni, M., Feagans, L., Hanvik, L. J., Helfgott, E., Koplewicz, H., & Overby, P. (1987). Piracetam and dyslexia: effects on reading tests. Journal of clinical psychopharmacology, 7(4), 230–237.

Dyslexia

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