Dyslexia – from the Greek ‘dys-’, meaning difficulty with, and ‘-lexia’, meaning words or language – is often referred to as a ‘specific learning difficulty’, meaning that it is not an all-round learning problem, but a particular difficulty at the word level.
Occurring across the range of intellectual abilities and affecting approximately 10% of individuals to varying degrees, dyslexia is biological in origin and defined primarily by a lack of phonological awareness which underpins the learning of literacy skills. It is a difficulty with words involving reading, spelling, writing and number work, and can also involve difficulty with remembering and sequencing information, word finding, organisation and co-ordination. Many individuals will have significant strengths in other areas. Dyslexia may co-exist with other specific learning difficulties such as dyspraxia and ADHD [for which a medical diagnosis is required].
The Equality Act 2010 recognises dyslexia as a disability. Others prefer to view it as a learning ‘difference’ – a different combination of strengths and weaknesses affecting the learning process in reading, spelling, writing and sometimes number and calculation.
Learners with dyslexia often have weaknesses in short-term memory, sequencing, speed of processing, auditory and/or perceptual skills and organisation. Some have enhanced functioning in areas such as visual/spatial skills and creativity, often displaying talent in the arts, photography, mechanics, sport, engineering, etc.
Dyslexia has a physiological basis. Research indicates neurological differences, which generally affect the left hemisphere of the brain that deals with language and sequential processing. Brain imaging shows that learners with dyslexia use different parts of the brain for reading than individuals without dyslexia. Some dyslexics tend to use a ‘coping’ style based on memorisation of sight words and visual cues, rather than using letter/sound knowledge to ‘sound out’ words. Others have difficulty recognising whole words they may have encountered before.
The most commonly observed symptom of dyslexia is a difficulty in identifying and manipulating sounds in words. Speech is often affected when putting sounds together to form spoken words. Due to difficulties with processing, the sounds of the language have not been sufficiently imprinted on the language centres in the left hemisphere of the brain. Difficulties are subsequently experienced in linking letters to sounds, and in correctly sequencing sounds in words, for writing and spelling.
Dyslexia occurs on a range, from mild to severe, in individuals from all ethnic and socio-economic groups, in all languages, and across the ability range. Males and females are affected equally, although females may develop better coping strategies that make identification less frequent.
The incidence of dyslexia depends on the criteria used to define it. Approximately 10% of the population are dyslexic, which is as many as 6 million people in the UK, or 2-3 children in every classroom. About 4% are severely affected with disruption to the development of literacy skills.
In relation to dyslexic learners’ ability, their difficulties in acquiring and applying basic skills are ‘unexpected’. They may demonstrate a clear verbal understanding of concepts but experience unexpected difficulty when it comes to transferring their knowledge onto paper. They may continue to have ‘persistent’ difficulties in certain areas despite quality learning opportunities which have helped others with apparently similar needs. Self-esteem may suffer with reduced motivation and sometimes behaviour problems.