About Dyslexia
Historically, there have been many theories as to what causes dyslexia; most recently, thanks to research using fMRI brain scans it has been widely accepted that it is a genetic, neurological condition which affects between 5% and 17% of the population. Dyslexia occurs across all cultures and written languages among persons with otherwise normal or above-average intelligence and is not considered a mental defect.
Given the historical development of human language, the prevalence of dyslexia makes some sense. Human beings have been using spoken language for 100,000 to 200,000 years, while the earliest writing systems date to only 7,000 years ago. Reading and writing have only become widespread activities very recently in human history (and many of the world's languages are still not written down). While evolution has allowed most humans to aquire spoken language naturally, the system of symbols which we use to depict these languages in writing needs to be taught. Because the majority of people use their brains in an efficient manner to process these symbols, most people learn to read and write without much difficulty. However, there are a considerable number of people who need a specifically developed form of instruction in order to learn to use the most efficient parts of their brain to process written language. This is the basis for the Orton-Gillingham method.
People commonly mistake dyslexia as seeing and writing letters "in reverse." While reversals of letters such as lowercase b and d are very common among those with dyslexia, the disorder is characterized more by a lack of understanding of the relationships between spoken and written language or a lack of ability to distinguish the individual sound-parts of a language (phonemes). In fact, reversals are quite common in children under age 7 because they have not yet developed body laterality; to them mirror-writing is the same as forward-writing.
Although many dyslexics are slow to learn to read, a child or adult with dyslexia may be able to read with some proficiency if they have memorized enough words. The person with dyslexia often remembers each word as a separate picture, as if they were pictograms instead of phonograms. However, a person who has developed this skill will have trouble when spelling or trying to decipher a word they have never seen before, due to a lack of understanding of the parts which make up the language. They may also write letters backward or transpose letters, words, or syllables when writing or speaking.
Signs of Dyslexia
The earliest signs of dyslexia in pre-school-age children are a lack of understanding of rhyme and difficulty learning the alphabet.
Other traits common in dyslexics include:
- Co-occuring conditions of dysgraphia, dyscalculia, other learning difficulties, and/or AD/HD
- Difficulties with organization, time management, and sequencing of events
- Difficulties with reading comprehension
- Anxiety and depression resulting from shame or blame for not being a good reader
- Ability to think "outside the box," in "3-D," or in a more creative way than non-dyslexics
With proper training, a dyslexic can learn to "re-wire" their brain with regards to reading and spelling. Orton-Gillingham instruction was specifically developed for this purpose.