Made by DATEXIS (Data Science and Text-based Information Systems) at Beuth University of Applied Sciences Berlin
Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
Dyslexic children require special instruction for word analysis and spelling from an early age. While there are fonts that may help people with dyslexia better understand writing, this might simply be due to the added spacing between words. The prognosis, generally speaking, is positive for individuals who are identified in childhood and receive support from friends and family.
Surface dyslexia is a type of dyslexia, or reading disorder. According to Marshall & Newcombe's (1973) and McCarthy & Warrington's study (1990), patients with this kind of disorder cannot recognize a word as a whole due to the damage of the left parietal or temporal lobe. Individuals with surface dyslexia are unable to recognize a word as a whole word and retrieve its pronunciation from memory. Rather, individuals with surface dyslexia rely on pronunciation rules. Thus, patients with this particular type of reading disorder read non-words fluently, like "yatchet", but struggle with words that defy pronunciation rules (i.e. exception words). For example, a patient with surface dyslexia can correctly read regular words like "mint", but will err when presented a word that disobeys typical pronunciation rules, like "pint". Often, semantic knowledge is preserved in individuals with surface dyslexia.
Deep dyslexia is a form of dyslexia that disrupts reading processes. Deep dyslexia may occur as a result of a head injury, stroke, disease, or operation. This injury results in the occurrence of semantic errors during reading and the impairment of nonword reading.
The term dyslexia comes from the Greek words 'dys' meaning 'impaired', and 'lexis' meaning 'word' and is used to describe disorders of language concerning reading and spelling.
Numerous models and hypotheses have been proposed in attempt to explain the broad range of symptoms experienced by deep dyslexics, but a definite consensus has yet to be reached. The proposed models and hypotheses have helped in treatment of some suffering patients, but only with certain specific symptoms. Additionally, the recovery seen is not experienced equally in all patients.
Phonological dyslexia is a reading disability that is a form of alexia (acquired dyslexia), resulting from brain injury, stroke, or progressive illness and that affects previously acquired reading abilities. The major distinguishing symptom of acquired phonological dyslexia is that a selective impairment of the ability to read pronounceable non-words occurs although the ability to read familiar words is not affected. It has also been found that the ability to read non-words can be improved if the non-words belong to a family of pseudohomophones.
Pure alexia results from cerebral lesions in circumscribed brain regions and therefore belongs to the group of acquired reading disorders, alexia, as opposed to developmental dyslexia found in children who have difficulties in learning to read.
Dyscalculia is thought to be present in 3–6% of the general population, but estimates by country and sample vary somewhat. Many studies have found prevalence rates by gender to be equivalent. Those that find gender difference in prevalence rates often find dyscalculia higher in females, but some few studies have found prevalence rates higher in males.
Through the use of compensation strategies, therapy and educational support, dyslexic individuals can learn to read and write. There are techniques and technical aids which help to manage or conceal symptoms of the disorder. Removing stress and anxiety alone can sometimes improve written comprehension. 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 how sounds blend into words. It has been found that reinforced collateral training focused on reading and spelling yields longer-lasting gains than oral phonological training alone. Early intervention that is done for children at a young age can be successful in reducing reading failure.
There is some evidence that the use of specially-tailored fonts may help with dyslexia. These fonts, which include Dyslexie, OpenDyslexic, and Lexia Readable, were created based on the idea that many of the letters of the Latin alphabet are visually similar and may, therefore, confuse people with dyslexia. Dyslexie and OpenDyslexic both put emphasis on making each letter more distinctive in order to be more easily identified. The benefits, however, might simply be due to the added spacing between words.
There have been many studies conducted regarding intervention in dyslexia. Among these studies one meta-analysis found that there was functional activation as a result.
There is no evidence demonstrating that the use of music education is effective in improving dyslexic adolescents' reading skills.
Dysgraphia is a biologically based disorder with genetic and brain bases. More specifically, it is a working memory problem. In dysgraphia, individuals fail to develop normal connections among different brain regions needed for writing. People with dysgraphia have difficulty in automatically remembering and mastering the sequence of motor movements required to write letters or numbers. Dysgraphia is also in part due to underlying problems in orthographic coding, the orthographic loop, and graphmotor output (the movements that result in writing) by one’s hands, fingers and executive functions involved in letter writing. The orthographic loop is when written words are stored in the mind’s eye, connected through sequential finger movement for motor output through the hand with feedback from the eye.
Dyscalculia is difficulty in learning or comprehending arithmetic, such as difficulty in understanding numbers, learning how to manipulate numbers, and learning facts in mathematics. It is generally seen as a specific developmental disorder.
Dyscalculia can occur in people from across the whole IQ range – often higher than average – along with difficulties with time, measurement, and spatial reasoning. Estimates of the prevalence of dyscalculia range between 3 and 6% of the population. In 2004, it was reported that a quarter of children with dyscalculia had ADHD.
In 2015, it was established that 11% of children with dyscalculia also have ADHD. Dyscalculia has also been associated with people who have Turner syndrome and people who have spina bifida.
Mathematical disabilities can occur as the result of some types of brain injury, in which case the proper term, acalculia, is to distinguish it from dyscalculia which is of innate, genetic or developmental origin.
Pure alexia, also known as agnosic alexia or alexia without agraphia or pure word blindness, is one form of alexia which makes up "the peripheral dyslexia" group. Individuals who have pure alexia suffer from severe reading problems while other language-related skills such as naming, oral repetition, auditory comprehension or writing are typically intact.
Pure alexia is also known as: "alexia without agraphia", "letter-by-letter dyslexia", "spelling dyslexia", or "word-form dyslexia". Another name for it is "Dejerine syndrome", after Joseph Jules Dejerine, who described it in 1892; however, when using this name, it should not be confused with medial medullary syndrome which shares the same eponym.
A reading disability is a condition in which a sufferer displays difficulty reading resulting primarily from neurological factors. Developmental Dyslexia, Alexia (acquired dyslexia), and Hyperlexia (word-reading ability well above normal for age and IQ).
Language-based learning disabilities or LBLD are "heterogeneous" neurological differences that can affect skills such as listening, reasoning, speaking, reading, writing, and maths calculations. It is also associated with movement, coordination, and direct attention. LBLD is not usually identified until the child reaches school age. Most people with this disability find it hard to communicate, to express ideas efficiently and what they say may be ambiguous and hard to understand
It is a neurological difference. It is often hereditary, and is frequently associated to specific language problems.
There are two types of learning disabilities: non-verbal, which includes disabilities from psychomotor difficulties to dyscalculia, and verbal, language based.
There are some common problems not related to dysgraphia but often associated with dysgraphia, the most common of which is stress. Often children (and adults) with dysgraphia will become extremely frustrated with the task of writing (and spelling); younger children may cry, pout, or refuse to complete written assignments. This frustration can cause the child (or adult) a great deal of stress and can lead to stress-related illnesses. This can be a result of any symptom of dysgraphia.
Deep dyslexia is usually classified as an "acquired reading disorder", as opposed to a "developmental dyslexia", in previously literate adults as a consequence of a brain injury. However, recently, developmental deep dyslexia has also been reported in children with Williams syndrome.
Deep dyslexia is considered to be a "central dyslexia" as compared to a "peripheral dyslexia". Peripheral dyslexics have difficulty matching the visual characteristics of letters that comprise a word to a stored memory of this word from prior encounters. Central dyslexics are unable to properly match the visual word to the word's meaning. They may also be incapable of speaking, or phonating, the sequence of written letters that they see into the word these letters represent. Deep dyslexia differs from other forms of central dyslexia (phonological dyslexia and surface dyslexia) in that deep dyslexics have many more symptoms and these symptoms are generally more severe. According to the "continuum" hypothesis, deep dyslexia is a more severe form of phonological dyslexia.
National Institute of Neurological Disorders and Stroke defines reading disability or dyslexia as follows: "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."
The NINDS definition is not in keeping with the bulk of scientific studies that conclude that there is no evidence to suggest that dyslexia and intelligence are related. The Rose Review 2009 Definition is more in keeping with modern research and debunked discrepancy model of dyslexia diagnosis:
- Dyslexia is a learning difficulty that primarily affects the skills involved in accurate and fluent word reading and spelling.
- Characteristic features of dyslexia are difficulties in phonological awareness, verbal memory and verbal processing speed.
- Dyslexia occurs across the range of intellectual abilities.
- It is best thought of as a continuum, not a distinct category, and there are no clear cut-off points.
- Co-occurring difficulties may be seen in aspects of language, motor co-ordination, mental calculation, concentration and personal organisation, but these are not, by themselves, markers of dyslexia.
- A good indication of the severity and persistence of dyslexic difficulties can be gained by examining how the individual responds or has responded to well founded intervention.
Semantic dyslexia is, as the name suggests, a subtype of the group of cognitive disorders known as alexia (acquired dyslexia). Those who suffer from semantic dyslexia are unable to properly attach words to their meanings in reading and/or speech. When confronted with the word "diamond", they may understand it as "sapphire", "shiny" or "diamonds"; when asking for a bus ticket, they may ask for some paper or simply "a thing".
Semantic dementia (SD) is a degenerative disease characterized by atrophy of anterior temporal regions (the primary auditory cortex; process auditory information) and progressive loss of semantic memory. SD patients often present with surface dyslexia, a relatively selective impairment in reading low-frequency words with exceptional or atypical spelling-to-sound correspondences.
Several studies have found that different levels of brain damage can lead to the occurrence of varying forms of non-word reading disorders. It has been found that during certain tasks, dyslexics had activated one of two regions of the brain: the Broca's area, which is responsible for speech, or the Wernicke's area, which is responsible for forming and understanding. Both areas were seldom active together. This study has led to the conclusion that there exist neural connection breakdowns between the language centers that may be causing dyslexia.
Hyperlexia is a syndrome characterized by a child's precocious ability to read. It was initially identified by Norman E. Silberberg and Margaret C. Silberberg (1967), who defined it as the precocious ability to read words without prior training in learning to read, typically before the age of 5. They indicated that children with hyperlexia have a significantly higher word-decoding ability than their reading comprehension levels. Children with hyperlexia also present with an intense fascination for written material at a very early age.
Hyperlexic children are characterized by having average or above-average IQs, and word-reading ability well above what would be expected given their age. First named and scientifically described in 1967 (Silverberg and Silverberg), it can be viewed as a superability in which word recognition ability goes far above expected levels of skill. Some hyperlexics, however, have trouble understanding speech. Some experts believe that most, or perhaps all children with hyperlexia, lie on the autism spectrum. However, one expert, Darold Treffert, proposes that hyperlexia has subtypes, only some of which overlap with autism. Between 5 and 20 percent of autistic children have been estimated to be hyperlexic.
Hyperlexic children are often fascinated by letters or numbers. They are extremely good at decoding language and thus often become very early readers. Some hyperlexic children learn to spell long words (such as "elephant") before they are two years old and learn to read whole sentences before they turn three.
An fMRI study of a single child showed that hyperlexia may be the neurological opposite of dyslexia.
Auditory processing disorder (APD), also known as central auditory processing disorder (CAPD), is an umbrella term for a variety of disorders that affect the way the brain processes auditory information. Individuals with APD usually have normal structure and function of the outer, middle and inner ear (peripheral hearing). However, they cannot process the information they hear in the same way as others do, which leads to difficulties in recognizing and interpreting sounds, especially the sounds composing speech. It is thought that these difficulties arise from dysfunction in the central nervous system.
The American Academy of Audiology notes that APD is diagnosed by difficulties in one or more auditory processes known to reflect the function of the central auditory nervous system.
APD can affect both children and adults, although the actual prevalence is currently unknown. It has been suggested that males are twice as likely to be affected by the disorder as females, but there are no good epidemiological studies.
For all practical purposes, there is no direct cure. Patients may improve if information is presented in other modalities than the damaged one. Different types of therapies can help to reverse the effects of agnosia. In some cases, occupational therapy or speech therapy can improve agnosia, depending on its cause.
Initially many individuals with a form of agnosia are unaware of the extent to which they have either a perceptual or recognition deficit. This may be caused by anosognosia which is the lack of awareness of a deficit. This lack of awareness usually leads to a form of denial and resistance to any form of help or treatment. There are various methods that can be used which can help the individual recognize the impairment in perception or recognition that they may have. A patient can be presented with a stimulus to the impaired modality only to help increase their awareness of their deficit. Alternatively, a task can be broken down into its component parts so that the individual can see each part of the problem caused by the deficit. Once the individual acknowledges their perceptual or recognition deficit, a form of treatment may be recommended. There are various forms of treatment such as compensatory strategies with alternate modalities, verbal strategies, alternate cues and organizational strategies.
Agnosia is the inability to process sensory information. Often there is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss. It is usually associated with brain injury or neurological illness, particularly after damage to the occipitotemporal border, which is part of the ventral stream. Agnosia only affects a single modality, such as vision or hearing. More recently, a top-down interruption is considered to cause the disturbance of handling perceptual information.
Some studies have demonstrated improvements in reading and spelling performance of individual children with surface dyslexia. Many of the interventions that exist are based on the dual route model of reading and utilize a targeted approach based on the individual assessment results.
Case studies conducted by Law and Cupples (2015) recommend first identifying specific oral reading difficulties experienced by the individual with surface dyslexia and based on the reading patterns identified designing a theoretically motivated and targeted treatment program. One of the interventions involved targeting visual-orthographic processing by increasing the efficiency by which surface dyslexics identified nonwords. The second intervention involved training in the identification and decoding of common letter patterns in irregular words.
15–20% of the children in the United States have a language-based learning disability. Of the students with specific learning disabilities receiving special education services, 70–80% have a discrepancy in reading.
In one paper, Darold Treffert proposes three types of hyperlexia. Specifically:
- Type 1: Neurotypical children who are very early readers.
- Type 2: Children on the autism spectrum who demonstrate very early reading as a splinter skill.
- Type 3: Very early readers who are not on the autism spectrum though there are some "autistic-like" traits and behaviours which gradually fade as the child gets older.
A different paper by Rebecca Williamson Brown, OD proposes only two types of hyperlexia. These are:
- Type 1: Hyperlexia marked by an accompanying language disorder.
- Type 2: Hyperlexia marked by an accompanying visual-spatial learning disorder.
It has been discovered that APD and ADHD present overlapping symptoms. Below is a ranked order of behavioral symptoms that are most frequently observed in each disorder. Professionals evaluated the overlap of symptoms between the two disorders. The order below is of symptoms that are almost always observed. This chart proves that although the symptoms listed are different, it is easy to get confused between many of them.
There is a high rate of co-occurrence between AD/HD and CAPD. Research shows that 84% of children with APD have confirmed or suspected ADHD. Co-occurrence between ADHD and APD is 41% for children with confirmed diagnosis of ADHD, and 43% for children suspected of having ADHD.