What is Dyslexia?

The International Dyslexia Association describes Dyslexia this way:

“Dyslexia is a specific learning disability that is neurobiological in origin. It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction. Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede growth of vocabulary and background knowledge.”

What this means in plain English:

Dyslexia is a specific learning disability that is neurobiological in origin.

This means dyslexia is something you are born with. People with dyslexia have observable differences in areas of their brains, notably in the Visual Word Form Area. Under fMRI, you can see visible differences between the brains of people with dyslexia and people without dyslexia. You can also see differences between the brains of people with dyslexia who have received tutoring and dyslexia intervention and those who have not – learning to read literally changes the brains of people with dyslexia.

If you are interested in the neuroanatomy of dyslexia, you may enjoy the book Reading in the Brain by Dr. Stanislaus Dehaene. 

Dyslexia is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities.

People with dyslexia have trouble recognizing words when they try to read. Some experience difficulty differentiating between letters. They have trouble with spelling, and with “sounding out” or breaking down words into understandable chunks.

These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction.

Phonology describes the relationship between letters and sounds. Most readers have learned the relationships between letters and sounds to the point that if you read a letter “k,” you automatically relate the letter to the the /k/ sound at the start of a word like “kite”. That is a phonological skill. Another phonological skill is the ability to take a word like “care”, take away the /c/ sound at the start, and understand that the word you have left sounds like the word “air”.

The difficulties with phonology that affect people with dyslexia are unrelated to their other cognitive abilities. Dyslexic people can be highly intelligent – and many are – and yet they struggle with reading and spelling. Their difficulties persist despite their teacher’s best attempts to help them learn to read and spell.

If you are interested in reading more about this topic, you may enjoy this paper: https://pmc.ncbi.nlm.nih.gov/articles/PMC4538781/

Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede growth of vocabulary and background knowledge.”

If reading is difficult and effortful and unpleasant, it can be hard to understand the meaning of what is being read. If reading is difficult and effortful and unpleasant, people don’t enjoy it and do less of it. The less people read, the less able they are to gain new knowledge.

Specialized tutoring, starting as early as possible, has been show scientifically to help people with dyslexia learn to read.