The neuroscience of dyslexia

The neuroscience of dyslexia : 

The neuroscience of dyslexia lisa lahey, b.ed.

international dyslexia association... : 

international dyslexia association... ...defines dyslexia as: ...a neurologically-based, often familial disorder which interferes with the acquisition of language. ...manifested by difficulties in receptive and expressive language, including phonological processing, in reading, writing, spelling, handwriting. ...not the result of lack of motivation, sensory impairment, inadequate instructional or environmental opportunities, but may occur with these conditions. ... life-long, individuals with dyslexia respond successfully to timely and appropriate intervention. -1994

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Key points in this definition include: familial disorder acquisition of language reading, writing, spelling math (dyscalculia) environmental opportunities not due to a lack of motivation life-long requires timely intervention

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Dyslexia is not only about literacy skills. It also interferes with: Memory Organization Social skills (ostracized by peers) Self-esteem Ability to complete school assignments Motivation and interest The individual’s abilities and her actual achievements Physical coordination Career success

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Not every child experiences all of these symptoms. Some children are well coordinated and may have a good vocabulary. Others may be quite strong in math, or conversely weak in math but fairly good readers. Dyslexia doesn’t discriminate between race or class however more boys than girls seem to express it. The ratios for boys versus girls are estimated between 3:1 and 5:1.

Co-morbidity : 

Dyslexia may occur with related conditions such as dyspraxia, attention-deficit disorder (with or without hyperactivity) and dysphasia. In childhood, its effects can be mis-attributed to emotional or behavioural disorders, or being a slow learner. Co-morbidity The occipital lobe in the left hemisphere is a major contributor to the infrastructure of the deeply dyslexic brain.

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The majority of experts concur that about 10% of the population are affected to a significant extent. This figure is based on the number of pupils who received normal schooling without significant emotional, social or medical defects, but whose literacy development by the end of primary school is more than 2 years behind grade level.

cognitive characteristics : 

cognitive characteristics

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Two views exist about deep dyslexia, which is acquired through brain damage: it represents reading by a multiply damaged left hemisphere reading system that it represents reading which relies extensively on right-hemisphere orthographic and semantic processing However some researchers have reported a brain-imaging study whose results, ‘‘preclude an explanation of deep dyslexia in terms of purely right-hemisphere word processing.’’

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This claim conflicts with the conclusions of previous published work, strongly supporting the RH hypothesis. the defining symptom is the semantic error in reading aloud. When deep dyslexics read single words aloud, their responses are often semantically, not orthographically or phonologically related to the word they are trying to read. For example error might be read as ‘‘wrong’’ or saxophone as ‘‘violin’’.

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Other error types also occur during reading aloud, especially visual errors (sleeve ‘‘sleep’’) and morphological errors (paint ‘‘painting’’). There are selective problems in reading function words aloud and words with abstract meanings. Nonwords cannot be read aloud. Read deep dyslexia is right hemisphere reading

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However no one has ever claimed that the reading of deep dyslexics relies exclusively on a right-hemisphere reading system. Reading aloud by deep dyslexics is accomplished via a sequence of three processing stages: orthographic, semantic, then phonological.

summary: deep dyslexia and reading aloud : 

As long as any one of these three stages cannot be completed by the left hemisphere then a right-hemisphere reading mechanism will be required to read aloud. When the deep dyslexic is asked to read a word aloud then the problem is this: orthographic input to a right hemisphere linguistic system is possible, but speech output is not; speech output from a left hemisphere linguistic system is possible, but orthographic input is not. summary: deep dyslexia and reading aloud

dyslexia testing : 

dyslexia testing There are 2 types of dyslexia testing: Screening test: used for a large number of students to divide the groups into those who need to take a comprehensive test and those who don’t. Comprehensive type: all-inclusive test that examines the root cause of learning difficulties. The tests include: reversal, visual scanning, sequencing, laterality, intelligence, spelling, comprehension test and reading. Online Dyslexia Assessment

variations in test-taking : 

variations in test-taking Comprehensive Distance Testing: the psychologist does not meet the child in order to ensure objectivity. The distant test may be taken anywhere even at home and the result provided by the distant test is more detailed than the report made by the psychologist. Psychologist-Conducted Comprehensive Dyslexia Test: Licensed psychologists facilitate their tests by visiting schools and colleges or in a clinic. The psychological assessments are completed allowing the psychologist to give suggestions on how a person can improve her learning techniques. Watch Dyslexia: Diagnosing Dyslexia

educational psychologist checklist : 

educational psychologist checklist Read educational psychologist checklist UK Dyslexia checklist – sample questions Did you worry  that s/he spoke later than other children of her age? Is there a family history of literacy difficulties? Is the child good at things that have a strong visual element? But inexplicitly poor in other set tasks? Is there evidence of laterality confusion? Does everything happen with the same side or are some things done left sided and others right sided? Can the child follow a number of instructions in sequence? For instance, “go to the living room and get my slippers, then bring them to me.” Is there evidence of reversals when writing? Does s/he have particular difficulty with literacy or one area of literacy, such as spelling or reading? Is the child noticeably inconsistent when reading, recognising words then being unable to read the same word later in the day/book/page ?

8 critical predictors for dyslexia : 

Family history of reading problems. Early language development delays. Print awareness Letter knowledge (name and sound) Phonological and phonemic awareness Expressive vocabulary Sentence story recall Rapid automatic naming 8 critical predictors for dyslexia 1. 2. 3. 4. 5. 6. 7. 8.

slow reading & disorganized brain tracks : 

slow reading & disorganized brain tracks Dyslexia marked by poor reading fluency may be caused by disorganized tracts of nerve fibres in the brain. A study using subjects with reading problems caused by a rare genetic disorder known as periventricular nodular heterotopia, or PNH demonstrated that the genetic mutation that causes PNH disrupts brain structure. In a normal brain much of the gray matter appears on the brain's surface, while white matter (consisting mostly of nerve fibres or "wiring" connecting areas of gray matter) runs deeper in the brain. In PNH, nodules of gray matter sit deep in the brain's core, inside the white matter, having failed to migrate out to the surface as the brain was developing. Read slow reading tied to disorganized brain tracks

sound therapy : 

sound therapy Read sound could rewire dyslexic children’s brains Neurologists at the Children’s Hospital Boston used an MRI to watch the brains of dyslexic kids as they listened to sound. When the sounds changed slowly, the children demonstrated the same neural activation as kids without dyslexia. When the sounds changed quickly dyslexic children processed them with the slow sound parts of their brain. Children with developmental dyslexia may hear in-between sounds. For example when a person tells a dyslexic child ‘ga,’ they hear a mix of ‘ga,’ ‘ka,’ ‘ba,’ and ‘wa’. Researchers had dyslexic children use a computer program designed to improve faster sound recognition. After several weeks, their brains acted more like non-dyslexic brains.

music therapy fails dyslexics : 

music therapy fails dyslexics While sound may function as a form of therapy for dyslexics, music therapy is unsuccessful. Dyslexics express problems in processing sounds and in how they manipulate the sounds from which words are composed. It was a short step between the notion that these phonological difficulties might also be associated with poor musical skills – amusia. This notion is based on studies that are flawed in two respects. Watch cognitive neuroscientists use sound training to help dyslexic children read

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The quality of published empirical studies is quite variable and many reviews of the field fail to discard papers containing insufficient information, either on materials and methods, or on experimental results. Many studies imply explicit statistical correlations. Such an approach leads to a circular argument (a) music discrimination predicts phonological skills, (b) which in turn predicts reading ability and (c) that reading ability implies phonological skills and so on. Flaw # 1 Flaw # 2 read sound training rewires dyslexic children’s brains for reading

einstein’s concentration method : 

einstein’s concentration method Watch albert einstein’s secret method for focus and concentration Einstein was dyslexic. He did not do well in school however he enjoyed experimenting and researching subjects that interested him. He had to train himself to focus in order to read research and this is purportedly a method that he used to improve his concentration.

memory and neuroscience : 

memory and neuroscience Working memory is associated with synchronisation of neurons, facilitating communication between different parts of the brain. On the basis of interaction between the brain areas, an individual’s working memory capacity can be predicted. The working memory can sustain only three or four objects at a time. The synchronisation of neuronal activity in different brain areas have a connection both to the maintenance and to the contents of working memory. The dyslexic child experiences short-term memory deficiency making it difficult to learn and retain words, and their meanings. Read human working memory is based on dynamic interaction networks in the brain

left and right-handedness and dyslexia : 

left and right-handedness and dyslexia Scientists identified a genetic variant (PCSK6 ) which influences whether a person with dyslexia is more skilled with the left or right hand. The finding identified a novel gene for handedness and provided the first genetic evidence to support a link between handedness and language-related disorders. Scientists have thought there may be a link between hand preference and disorders that affect language development, such as autism and specific language impairment (SLI). The study provides the first genetic link between handedness, brain asymmetry and reading ability. Read handedness and language-related disorders: gene discovery supports a link

dyslexia subtypes : 

dyslexia subtypes It is increasingly accepted that dyslexia is not a unique entity, but might result from different neuro-cognitive pathologies. Researchers have been looking for a way to distinguish between different types of dyslexia for several years, and this research is among the first to show a direct link between brain structure and symptom severity. A research study using MRI imaging compared the brains of 38 people with dyslexia to a model 'typical brain' created by combining the scans of 39 normal readers. In all cases, differences could be seen in either the right cerebellar declive or the right lentiform nucleus. These were associated with varying performance in language tests.

dyslexia .... the gift : 

dyslexia .... the gift Tom Cruise actor Albert Einstein physicist Nelson Rockefeller billionaire Thomas Edison inventor Marilyn Monroe actress Magic Johnson basketball player Winston Churchill Prime minister of England Keanu Reeves actor George Clooney actor Anthony Hopkins actor Laura Flynn Boyle actress Agatha Christie author Muhammed Ali boxer Leonardo da Vinci artist Walt Disney cartoonist Harry Belafonte singer Alexander Graham Bell inventor Harrison Ford actor Whoopi Goldberg actress John F. Kennedy President Every child is gifted.....some children simply take a little longer to unwrap their gifts. unknown Many dyslexics  are wrongly  placed in special education programs with slow learners....  Years later  these  people  make the Dean’s List and become educators, lawyers, and doctors.... When non-dyslexics gain understanding of dyslexia the education system is certain to improve. Lisa Lahey, B.Ed.