Dyslexia is a specific learning difficulty that causes problems in developing literacy skills. It is neurological in origin and may be inherited. It may also affect other learning that relies on symbolic representations such as maths and reading music. It can occur in a person whatever his or her intelligence. Sometimes people with dyslexia may show poor motivation and low self-esteem or they may have had a lack of educational opportunities, but these are not the causes of dyslexia.

People with dyslexia often have a poor working memory that appears to limit the number of verbal items they can hold in their mind at any one time and affects their ability to use their working memory for the complex tasks involved in reading and writing. They typically have difficulty in separating and manipulating the sounds within words. Children with dyslexia are often late in learning the names of colours and numbers, and learning verbal sequences such as the days of the week and months of the year.

Dyslexics may have either a weak visual or a weak auditory memory or both. Poor visual memory makes it difficult to learn to read flash cards and to copy letters and writing. Poor auditory memory affects the ability to learn the links between sounds and letters and to manipulate the sounds in words for reading and spelling.