No two dyslexics are the same. But they all have one thing in common: a weakness with phonological awareness - the ability to identify and manipulate the specific sounds that make up a word. Research suggests this is due to a weakness in the working memory.
One of the most obvious signs of dyslexia is when the standard of a pupil's written work falls well below their ability to express themselves orally.
Either they write correctly but at a shorter length and more simply than their oral ability would suggest; or they write at their intellectual level but their work is riddled with errors, including omitted or contracted words, irrelevancies and poor spelling. The reason for this is lack of what is called "automaticity". As Nicolson wrote in 2001: "The behavioural symptoms of dyslexia can be characterised as difficulties in skill automatisation - the process by which, after long practice, skills become so fluent they no longer need conscious control."
For most people, repeated practice at processing information means tasks, such as multiplication tables and sight word recognition, become automatic.
This means the stored information is retrieved rapidly and the brain is relieved of having to process individual units of information. Automatic processes are so fast they do not reduce the capacity available for other tasks, permitting the brain to perform more complex processing and problem-solving. With dyslexics, the lower order processes of identifying letters and words when reading, and controlling the pen when writing, are not automatic so they have fewer resources available for higher order processes of thought and composition.
Equally, if the working memory is fully engaged in higher order processes such as selecting content, style and language to suit the task and audience when writing, the pupil with poor automatic low-level skills may write incoherently and make apparently careless mistakes. My research showed the effects of lack of automaticity on pupils' writing.
I compared the performance of a group of 12 dyslexic pupils aged between 13 and 18, all with an educational psychologist's report, with a group of 12 controls matched for age, gender, school and non-verbal IQ. They were compared on three writing tasks: a dictation, a copying exercise and retelling a well-known story.
Each of the writing tasks was performed twice, once handwritten and once typed, with the autocorrect and spell-check functions on the computer disabled. In 11 separate comparisons, across all three tasks, the handwritten work of the dyslexic group was significantly worse than that of the control group. But there was no significant difference between the typed work of the two groups.
So dyslexic pupils find it helpful to write using a keyboard not because they cannot write by hand, are lazy, or want to rely on a computer programme to help them spell. It is because the demands on their working memory are reduced when they are allowed to use a keyboard rather than having to retrieve from memory each time how to form a letter or spell a word. Typing provides far less distraction from expressing what they want to write. Quite simply, most dyslexics report that they can "think better"
when they type Louise Green is a specialist teacher who gives one-on-one and small group tuition to dyslexic and dyspraxic pupils at an independent secondary school, three state grammar schools and an RAF base. She is chair of the Professional Association of Teachers of Students with Specific Learning Difficulties and a trustee of the British Dyslexia Association
Baddeley, A. D. (1996) The Concept of Working Memory in Gathercole, S. E.
(Ed.) Models of Short-term Memory, Psychology Press
Green, L. (2001) Investigating Differences in Output Between Hand-Written and Computer Generated Work in Secondary Aged Children with Specific Learning Difficulties, University College London
Jones, D. and Christensen, C. A. (1999) Relationship Between Automaticity in Handwriting and Students' Ability to Generate Written Text, Journal of Educational Psychology 1999 91:1 44 - 4
Nicolson, R. I., Fawcett, A. J. and Dean, P. (2001) A TINS Debate - Hindbrain versus the Forebrain: A Case for Cerebellar Deficit in Developmental Dyslexia Trends in Neurosciences 24:9 508 - 511