A long and detailed but not excessively technical look at the neurological underpinnings of dyslexia.
“Both phonological and visual hypotheses have received valuable contribution from modern functional imaging techniques. Results of recent PET and functional MRI studies are reported here in some detail. Finally, one attractive interpretation of available evidence points to dyslexia as a multi-system deficit possibly based on a fundamental incapacity of the brain in performing tasks requiring processing of brief stimuli in rapid temporal succession. It is proposed that this so-called `temporal processing impairment’ theory of dyslexia could also account for at least some of the perceptual, motor and cognitive symptoms very often associated with the learning disorder, a coincidence that has remained unexplained so far“.
The neurological basis of developmental dyslexia.
During my recent visit to Bramhall to see the Interactive Metronome in practice I also had the opportunity to try out the Lucid Adult Dyslexia Screening software which the centre uses to gain an objective assessment of the clients abilities. The software, from Lucid Research, is a way of quickly identifying adults who may have dyslexia. It is part of a range of software that Lucid produce aimed at detecting dyslexia at all stages of the eduction system. They even have a version that is targeted at children as young as four where as most dyslexia related tests cannot be used on under sevens.
The adult test consists of four stages. The first is a reasoning test where you have to identify the missing symbol. This is similar to questions found in many IQ tests. The second test is a word recognition test in which half-a-dozen words are placed randomly on the screen and you have to click on the only real, correctly spelt word. The third test focuses on word construction. Nonsense words are spoken by the computer’s speaker and you have to identify the three syllables, in the correct order, that make up that word from a palette of nine syllables. The final test is a short-term, auditory-loop test. The computer reads out two or more digits and then you have to type those digits in backwards. So if the computer says "3 8 4" you must enter "4 8 3".
Based on the combined scores Lucid assesses the probability of dyslexia summarised into four grades: High, Moderate, Borderline and Low. With the grading teachers can decide if its appropriate to involve educational psychologists and how to adapt their teaching to fit the child’s needs. The manual with the software [ PDF ] goes into some depth on how the tests were calibrated and the studies done to ensure the results have a high degree of reliability.
For my test results the software classified me as borderline risk of dyslexia. Looking at the individual scores my reasoning, word recognition and memory test were all very good. The one test I did poorly on was the word construction test. Here I scored five, where a score of one is very good and a score of nine is very poor. This suggestions that I still have relatively weak phonological skills which is common in dyslexics and what some academics consider all that dyslexia is.
This software is very good at producing a quick assessment, the whole process only takes about 20 minutes and it tests those abilities that are often weak in dyslexics. The software is well made but does have one or two minor quirks and its a shame that its aimed at schools and practitioners rather than parents. An online version of this software that was free, or even if it cost about £10 to use, would be a fantastic resource for everyone worried about dyslexia.
Meares-Irlen Syndrome (also known as Scotopic sensitivity syndrome and ASFEDIA) is a visual problem that is treated through the use of colored overlays and glasses. Designing web pages that are easily readable for people with this problem can be difficult.TechDis is a UK body that looks at technology to help disabled students and they have produced a paper on good colour choices for web pages. The paper, Colour & Contrast Accessibility Issues: for the design of e-learning materials covers colours for dyslexics as well as other visual problems.
Here is a good and comprehensive history of entrainment using flashing lights and audio. This is the technique I experienced and entrainment is part of many different treatments for a wide range of problems. The article includes lots of information on studies of light therapy’s effectiveness and mentions studies on ADD / ADHD and IQ. I will be tracking those studies and posting their results here.
Meares-Irlen Syndrome (also known as Scotopic sensitivity syndrome) is controversial visual problem linked to dyslexia that is treated by coloured (colored) lens or overlays. A study published in the Journal of Research in Reading demonstrates that coloured overlays can help far more children than expected.
“In this study both [Rate of Reading test (RRT) and Developmental Eye Movement (DEM) test] were utilised to determine whether coloured overlays could enhance reading performance or scanning …. Improvements to the DEM scores occurred in 88% of children who continued to use overlays for more than 3 months. This compared with 60% sensitivity in the RRT.“
Predicting the continued use of overlays in school children
See also: Toolbar for Dyslexia and Meares-Irlen Syndrome.
Here is an idea I wish I had thought of. The colour and font of text can make a big difference to dyslexics so a company called Textic have release a web toolbar that allows the user to control the colour and font used on a web page. This could help sufferers of Meares-Irlen syndrome.
The Sound Learning Centre is running a one day workshop for parent and carers on how to help children with sensory and learning difficulties.
“This groundbreaking course is based on more than ten years of therapeutic work with children and adults with learning and sensory difficulties and incorporates the latest findings in these fields. You will gain a comprehensive understanding of how hearing, vision, reflexes and sensori-neural systems impact on healthy child development; learn how to evaluate and track progress yourself; have all the tools to implement an effective home programme to support your child in their further development and learning. The suggested activities and included materials are suitable for children aged three to early teens.“
The course takes place on 24th November 2005 in North London, UK and costs £125 per person. I’ve used the treatments provided by the Sound Learning Centre myself and they have also featured on BBC TV.
There is an interesting post on Eide Neurolearning about areas of the brain that combine different sensory information.
“The presence of multimodal sensory areas means that injury in one location can affect multiple sensory systems at once. It explains the surprisingly common occurrence of multiple mild sensory deficits (mild visual and auditory processing problems, for instance, or mild visual and balance difficulties)in conditions such as mild birth injury, prematurity, dyslexia, or autism spectrum disorders“.
On Eide Neurololearning blog there is an interesting article on how men & women hear differently and how that may effect the diagnosis of ADD / ADHD.
The Eide Neurolearning Blog has an interesting post on what they are calling Stealth Dyslexia: “The key feature of the stealth dyslexic is an enormous gap between written and oral expression. For individual stealth dyslexics, there are a range of dyslexia-related traits which can contribute to writing difficulties (also known as dysgraphia)- most common are visual letter or word form difficulties, but sequencing and sensory-motor issues are often also part of the picture”