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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)
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There are tests that can indicate with high probability whether a person is a dyslexic. If diagnostic testing indicates that a person may be dyslexic, such tests are often followed up with a full diagnostic assessment to determine the extent and nature of the disorder. Tests can be administered by a teacher or computer. Some test results indicate how to carry out teaching strategies.
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.
At its most basic level, dyscalculia is a learning disability affecting the normal development of arithmetic skills.
A consensus has not yet been reached on appropriate diagnostic criteria for dyscalculia. Mathematics is a specific domain that is complex (i.e. includes many different processes, such as arithmetic, algebra, word problems, geometry, etc.) and cumulative (i.e. the processes build on each other such that mastery of an advanced skill requires mastery of many basic skills). Thus dyscalculia can be diagnosed using different criteria, and frequently is; this variety in diagnostic criteria leads to variability in identified samples, and thus variability in research findings regarding dyscalculia.
Other than using achievement tests as diagnostic criteria, researchers often rely on domain-specific tests (i.e. tests of working memory, executive function, inhibition, intelligence, etc.) and teacher evaluations to create a more comprehensive diagnosis. Alternatively, fMRI research has shown that the brains of the neurotypical children can be reliably distinguished from the brains of the dyscalculic children based on the activation in the prefrontal cortex. However, due to the cost and time limitations associated with brain and neural research, these methods will likely not be incorporated into diagnostic criteria despite their effectiveness.
In order to assess an individual for agnosia, it must be verified that the individual is not suffering from a loss of sensation, and that both their language abilities and intelligence are intact. In order for an individual to be diagnosed with agnosia, they must only be experiencing a sensory deficit in a single modality. To make a diagnosis, the distinction between apperceptive and associative agnosia must be made. This distinction can be made by having the individual complete copying and matching tasks. If the individual is suffering from a form of apperceptive agnosia they will not be able to match two stimuli that are identical in appearance. In contrast, if an individual is suffering from a form of associative agnosia, they will not be able to match different examples of a stimulus. For example, an individual who has been diagnosed with associative agnosia in the visual modality would not be able to match pictures of a laptop that is open with a laptop that is closed.
1. SCAN is the most common tool for diagnosing APD, and it also standardized. It is composed for four subsets: discrimination of monaurally presented single words against background noise, acoustically degraded single words, dichotically presented single words, sentence stimuli. Different versions of the test are used depending on the age of the patient.
2. Random Gap Detection Test (RGDT) is also a standardized test. It assesses an individual’s gap detection threshold of tones and white noise. The exam includes stimuli at four different frequencies (500, 1000, 2000, and 4000 Hz) and white noise clicks of 50 ms duration. It is a useful test because it provides an index of auditory temporal resolution. In children, an overall gap detection threshold greater than 20 ms means they have failed.
3. Gaps in Noise Test (GIN) also measures temporal resolution by testing the patient's gap detection threshold in white noise.
4. Pitch Patterns Sequence Test (PPT) and Duration Patterns Sequence Test (DPT) measure auditory pattern identification. The PPS has s series of three tones presented at either of two pitches (high or low). Meanwhile, the DPS has a series of three tones that vary in duration rather than pitch (long or short). Patients are then asked to describe the pattern of pitches presented.
Individuals with pure alexia usually have difficulty reading words as well as difficulty with identifying letters. In order to assess whether an individual has pure alexia, tests of copying and recognition must be performed. An individual with pure alexia should be able to copy a set of words, and should be able to recognize letters.
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.
Research on subtypes of dyscalculia has begun without consensus; preliminary research has focused on comorbid learning disorders as subtyping candidates. The most common comorbidity in individuals with dyscalculia is dyslexia. Most studies done with comorbid samples versus dyscalculic-only samples have shown different mechanisms at work and additive effects of comorbidity, indicating that such subtyping may not be helpful in diagnosing dyscalculia. But there is variability in results at present.
Due to high comorbidity with other disabilities such as dyslexia and ADHD, some researchers have suggested the possibility of subtypes of mathematical disabilities with different underlying profiles and causes. Whether a particular subtype is specifically termed "dyscalculia" as opposed to a more general mathematical learning disability is somewhat under debate in the scientific literature.
- Semantic memory: This subtype often coexists with reading disabilities such as dyslexia and is characterized by poor representation and retrieval from long-term memory. These processes share a common neural pathway in the left angular gyrus, which has been shown to be selective in arithmetic fact retrieval strategies and symbolic magnitude judgments. This region also shows low functional connectivity with language-related areas during phonological processing in adults with dyslexia. Thus, disruption to the left angular gyrus can cause both reading impairments and difficulties in calculation. This has been observed in individuals with Gerstmann syndrome, of which dyscalculia is one of constellation of symptoms.
- Procedural concepts: Research by Geary has shown that in addition to increased problems with fact retrieval, children with math disabilities may rely on immature computational strategies. Specifically, children with mathematical disabilities showed poor command of counting strategies unrelated to their ability to retrieve numeric facts. This research notes that it is difficult to discern whether poor conceptual knowledge is indicative of a qualitative deficit in number processing or simply a delay in typical mathematical development.
- Working memory: Studies have found that children with dyscalculia showed impaired performance on working memory tasks compared to neurotypical children. Furthermore, research has shown that children with dyscalculia have weaker activation of the intraparietal sulcus during visuospatial working memory tasks. Brain activity in this region during such tasks has been linked to overall arithmetic performance, indicating that numerical and working memory functions may converge in the intraparietal sulcus. However, working memory problems are confounded with domain-general learning difficulties, thus these deficits may not be specific to dyscalculia but rather may reflect a greater learning deficit. Dysfunction in prefrontal regions may also lead to deficits in working memory and other executive function, accounting for comorbidity with ADHD.
Studies have also shown indications of causes due to congenital or hereditary disorders, but evidence of this is not yet concrete.
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.
Though there have been ample attempts to rehabilitate patients with pure alexia, few have proven to be effective on a large scale. Most rehabilitation practices have been specialized to a single patient or small patient group. At the simplest level, patients seeking rehabilitation are asked to practice reading words aloud repeatedly. This is meant to stimulate the damaged system of the brain. This is known as multiple oral re-reading (MOR) treatment. This is a text-based approach that is implemented in order to prevent patients from LBL reading. MOR works by reading aloud the same text repeatedly until certain criteria are reached. The most important criteria for a pure alexic patient is reading at an improved rate. The treatment aims to shift patients away from the LBL reading strategy by strengthening links between visual input and the associated orthographic representations. This repetition supports the idea of using top-down processing initially minimize the effects peripheral processing which were demonstrated in the study above. From here, the goal is to increasing bottom-up processing. This will hopefully aid in word recognition and promote interactive processing of all available information to support reading. 'The supported reading stimulation from MOR has a rehabilitative effect so that reading rate and accuracy are better for untrained text, and word-form recognition improves as evidenced by a reduced word-length effect.' These tactics have seen quite good success.
Another tactic that has been employed is the use of cross modal therapy. In this therapy, patients are asked to trace the words in which they are trying to read aloud. There has been success using cross modal therapy such as kinaesthetic or motor-cross cuing therapy, but tends to be a more feasible approach for those on the slower reading end of the spectrum.
APD is a difficult disorder to detect and diagnose. The subjective symptoms that lead to an evaluation for APD include an intermittent inability to process verbal information, leading the person to guess to fill in the processing gaps. There may also be disproportionate problems with decoding speech in noisy environments.
APD has been defined anatomically in terms of the integrity of the auditory areas of the nervous system. However, children with symptoms of APD typically have no evidence of neurological disease and the diagnosis is made on the basis of performance on behavioral auditory tests. Auditory processing is "what we do with what we hear", and in APD there is a mismatch between peripheral hearing ability (which is typically normal) and ability to interpret or discriminate sounds. Thus in those with no signs of neurological impairment, APD is diagnosed on the basis of auditory tests. There is, however, no consensus as to which tests should be used for diagnosis, as evidenced by the succession of task force reports that have appeared in recent years. The first of these occurred in 1996. This was followed by a conference organized by the American Academy of Audiology. Experts attempting to define diagnostic criteria have to grapple with the problem that a child may do poorly on an auditory test for reasons other than poor auditory perception: for instance, failure could be due to inattention, difficulty in coping with task demands, or limited language ability. In an attempt to rule out at least some of these factors, the American Academy of Audiology conference explicitly advocated that for APD to be diagnosed, the child must have a modality-specific problem, i.e. affecting auditory but not visual processing. However, an ASHA committee subsequently rejected modality-specificity as a defining characteristic of auditory processing disorders.
There have been many different studies done in an attempt to treat deep dyslexics, all which have been met with varying success. One method that has been frequently used is to teach patients to sound out words using grapheme-to-phoneme correspondence rules (for example, using single letter graphemes such as the letter 'B" to link with larger words such as "Baby", allowing for association of phonemes). Such methods are known as "non-lexically based reading treatments". Other studies have looked at attempting to repair the semantic-lexical route, known as "lexically based treatment". Regardless of the methodology, treatment studies with deep dyslexics are difficult because much of the information regarding this disability is still heavily debated. Treatment options may be successful on repairing one route of reading but not another, and success for one patient may not translate to success in another.
Treatment for dysgraphia varies and may include treatment for motor disorders to help control writing movements. The use of occupational therapy can be effective in the school setting, and teachers should be well informed about dysgraphia to aid in carry-over of the occupational therapist's interventions. Treatments may address impaired memory or other neurological problems. Some physicians recommend that individuals with dysgraphia use computers to avoid the problems of handwriting. Dysgraphia can sometimes be partially overcome with appropriate and conscious effort and training. The International Dyslexia Association suggests the use of kinesthetic memory through early training by having the child overlearn how to write letters and to later practice writing with their eyes closed or averted to reinforce the feel of the letters being written. They also suggest teaching the students cursive writing as it has fewer reversible letters and can help lessen spacing problems, at least within words, because cursive letters are generally attached within a word.
Diagnosing dysgraphia can be challenging but can be done at facilities specializing in learning disabilities. It is suggested that those who believe they may have dysgraphia seek a qualified clinician to be tested. Clinicians will have the client self-generate written sentences and paragraphs, and copy age-appropriate text. They will assess the output of writing, as well as observe the client's posture while writing, their grip on the writing instrument, and will ask the client to either tap their finger or turn their wrists repeatedly to assess fine motor skills.
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.
The diagnosis of amusia requires individuals to detect out-of-key notes in conventional but unfamiliar melodies. A behavioral failure on this test is diagnostic because there is typically no overlap between the distributions of the scores of amusics and controls. Such scores are generally obtained through the Montreal Battery of Evaluation of Amusia (MBEA), which involves a series of tests that evaluate the use of musical characteristics known to contribute to the memory and perception of conventional music. The battery comprises six subtests which assess the ability to discriminate pitch contour, musical scales, pitch intervals, rhythm, meter, and memory. An individual is considered amusic if he/she performs two standard deviations below the mean obtained by musically-competent controls. This musical pitch disorder represents a phenotype that serves to identify the associated neuro-genetic factors. Both MRI-based brain structural analyses and electroencephalography (EEG) are common methods employed to uncover brain anomalies associated with amusia (See Neuroanatomy). Additionally, voxel-based morphometry (VBM) is used to detect anatomical differences between the MRIs of amusic brains and musically intact brains, specifically with respect increased and/or decreased amounts of white and grey matter.
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.
Many normed assessments can be used in evaluating skills in the primary academic domains: reading, including word recognition, fluency, and comprehension; mathematics, including computation and problem solving; and written expression, including handwriting, spelling and composition.
The most commonly used comprehensive achievement tests include the Woodcock-Johnson IV (WJ IV), Wechsler Individual Achievement Test II (WIAT II), the Wide Range Achievement Test III (WRAT III), and the Stanford Achievement Test–10th edition. These tests include measures of many academic domains that are reliable in identifying areas of difficulty.
In the reading domain, there are also specialized tests that can be used to obtain details about specific reading deficits. Assessments that measure multiple domains of reading include Gray's Diagnostic Reading Tests–2nd edition (GDRT II) and the Stanford Diagnostic Reading Assessment. Assessments that measure reading subskills include the Gray Oral Reading Test IV – Fourth Edition (GORT IV), Gray Silent Reading Test, Comprehensive Test of Phonological Processing (CTOPP), Tests of Oral Reading and Comprehension Skills (TORCS), Test of Reading Comprehension 3 (TORC-3), Test of Word Reading Efficiency (TOWRE), and the Test of Reading Fluency. A more comprehensive list of reading assessments may be obtained from the Southwest Educational Development Laboratory.
The purpose of assessment is to determine what is needed for intervention, which also requires consideration of contextual variables and whether there are comorbid disorders that must also be identified and treated, such as behavioral issues or language delays. These contextual variables are often assessed using parent and teacher questionnaire forms that rate the students' behaviors and compares them to standardized norms.
However, caution should be made when suspecting the person with a learning disability may also have dementia, especially as people with Down's syndrome may have the neuroanatomical profile but not the associated clinical signs and symptoms. Examination can be carried out of executive functioning as well as social and cognitive abilities but may need adaptation of standardized tests to take account of special needs.
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.
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.
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.
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.
Special education classes are the primary treatment. These classes focus on activities that sustain growth in language skills. The foundation of this treatment is repetition of oral, reading and writing activities. Usually the SLP, psychologist and the teacher work together with the children in small groups in the class room.
Another treatment is looking at a child's needs through the Individual Education Plan (IEP). In this program teachers and parents work together to monitor the progress of the child's comprehensive, verbal, written, social, and motor skills in school and in the home. Then the child goes through different assessments to determine his/her level. The level that the child is placed in will determine the class size, number of teachers, and the need for therapy.
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.
Assessments for developmental coordination disorder typically require a developmental history, detailing ages at which significant developmental milestones, such as crawling and walking, occurred. Motor skills screening includes activities designed to indicate developmental coordination disorder, including balancing, physical sequencing, touch sensitivity, and variations on walking activities.
The American Psychiatric Association has four primary inclusive diagnostic criteria for determining if a child has developmental coordination disorder.
The criteria are as follows:
1. Motor Coordination will be greatly reduced, although the intelligence of the child is normal for the age.
2. The difficulties the child experiences with motor coordination or planning interfere with the child's daily life.
3. The difficulties with coordination are not due to any other medical condition
4. If the child does also experience comorbidities such as mental retardation; motor coordination is still disproportionally affected.
Screening tests which can be used to assess developmental coordination disorder include:-
- Movement Assessment Battery for Children (Movement-ABC – Movement-ABC 2)
- Peabody Developmental Motor Scales- Second Edition (PDMS-2)
- Bruininks-Oseretsky Test of Motor Proficiency (BOTMP-BOT-2)
- Motoriktest für vier- bis sechsjährige Kinder (MOT 4-6)
- Körperkoordinationtest für Kinder (KTK)
- Test of Gross Motor Development, Second Edition (TGMD-2)
- Maastrichtse Motoriek Test (MMT)
- Wechsler Adult Intelligence Scale (WAIS-IV)
- Wechsler Individual Achievement Test (WAIT-II)
- Test of Word Reading Efficiency (TOWRE-2)
- Developmental Coordination Disorder Questionnaire (DCD-Q)
- Children's Self-Perceptions of Adequacy in, and Predilection for Physical Activity (CSAPPA)
Currently there is no single gold standard assessment test.
A baseline motor assessment establishes the starting point for developmental intervention programs. Comparing children to normal rates of development may help to establish areas of significant difficulty.
However, research in the "British Journal of Special Education" has shown that knowledge is severely limited in many who should be trained to recognise and respond to various difficulties, including developmental coordination disorder, dyslexia and deficits in attention, motor control and perception (DAMP). The earlier that difficulties are noted and timely assessments occur, the quicker intervention can begin. A teacher or GP could miss a diagnosis if they are only applying a cursory knowledge.
"Teachers will not be able to recognise or accommodate the child with learning difficulties in class if their knowledge is limited. Similarly GPs will find it difficult to detect and appropriately refer children with learning difficulties."