Dyslexia is a common type of learning difficulty that primarily affects the skills involved in the reading and spelling of words.
Dyslexia should be recognised as a spectrum disorder, with symptoms ranging from very mild to very severe. In particular, people with dyslexia have difficulties with:
- phonological awareness
- verbal memory
- verbal processing speed
These terms are explained in more detail below.
Phonological awareness
Phonological awareness is thought to be a key skill in early reading and spelling development. It is the ability to identify how words are made up of smaller units of sound, known as phonemes. Changes in the sounds that make up words can lead to changes in their meaning.
So, for example, a child with a good level of phonological awareness would understand that if you change the letter ‘p’ in the word ‘pat’ to ‘s’, the word would become ‘sat’.
Verbal memory
Verbal memory is the ability to remember a sequence of verbal information for a short period of time.
For example, the ability to remember a short list such as ‘red, blue, green’, or a set of simple instructions, such as ‘put on your gloves and your hat, find the lead for the dog, and then go to the park’.
Verbal processing speed
Verbal processing speed is the time that it takes to process and recognise familiar verbal information, such as letters and digits.
For example, your verbal processing speed is the time that it takes you to look at the following numbers and letters - ‘B’, ‘B,’ ‘C’, 1’, and then realise that the information relates to the name of the television channel BBC1.
Dyslexia and intelligence
Even though dyslexia is classed as a learning difficulty, there is no connection between dyslexia and a child’s intelligence. Children of all intellectual abilities - from low to high intelligence - can be affected by dyslexia.
Similarly, a child’s difficulty with reading and spelling is not determined by their intelligence, but by how severe their dyslexia is. Children with average intelligence and mild dyslexia are likely to be more skilled at reading and writing than children with high intelligence and severe dyslexia.
How common is dyslexia?
Dyslexia is thought to be one of the most common learning difficulties.
Dyslexia appears to be more common in boys than girls. For example, it is estimated that boys are one-and-a-half to three times more likely to develop dyslexia than girls.
Dyslexia affects people of all ethnic backgrounds, although a person’s native language can play an important role. A language where there is a clear connection between how a word is written and how it sounds, and consistent rules grammatical rules, such as in Italian and Spanish, can be more straightforward for a person with mild to moderate dyslexia to cope with.
However, languages such as English, where there is often no clear connection between the written form and sound, as in words such as ‘cough’ and ‘dough’, can be more challenging for a person with dyslexia.
The cause (or causes) of dyslexia is unknown. However, many experts think that the condition is probably caused by genetic factors that affect the normal development of certain areas of the brain.
Although there is currently no cure for dyslexia, a range of educational programmes and interventions have proven effective in improving reading and writing skills in many children with the condition.
Outlook
The outlook for dyslexia is highly variable. Around 95% of children respond well to educational interventions and go on to make moderate to good progress with reading and writing.
The remaining 5% of children continue to find reading and writing difficult and will require more intensive support and long-term assistance.
It should be stressed that although children with dyslexia will face challenges on a day-to-day basis, even children who have severe dyslexia can go on to lead full and productive lives.