A hidden disability

Every day, thousands of dyslexics go about their lives and by and large, the majority of people with whom they interact will not know they have dyslexia. Dyslexia is not obvious to the naked eye. It is hidden until the person is confronted with an activity that involves written text.

Contrary to what was once thought—that dyslexia was a visual problem (i.e., seeing or writing the letters backwards)—we now know that dyslexia is a language-based learning disability.

By language-based learning disability, we are referring to a difficulty processing the sounds (phonemes) of our language. Rather than a problem with oral language (i.e., understanding and speaking) in general, the difficulty lies in processing the phonological (sound) aspect of language: in the ability to perceive and manipulate the individual sounds in words. These skills underlie learning to decode words and are required if one is to "break the reading code" and become a good reader and speller.

Dyslexics have difficulty performing such tasks as "say the individual sounds in cat" (k-a-t) or say "cup without the ‘kuh’" (up). These are tasks that require taking apart words into the component sounds, referred to as tasks of analysis. Tasks of synthesis, which can also be difficulty for dyslexics, are ones that require putting the individual units together to make a word—"What word do these sounds make? j-u-m-p"; "What word do these syllables make? cal-en-dar".

The phonological component of language also includes one's ability to rapidly access the lexicon (individual words). Difficulty with rapid word access can affect one's ability to read fluently, which in turn can affect comprehension. Short term memory and working memory can also be affected, which contribute to comprehension and spelling problems.

The phonological model of dyslexia is consistent with the current neurobiological research findings. Research has identified that the dyslexic activates different parts of the brain when reading as compared to the non-dyslexic reader. These findings are evident regardless of age, indicating that dyslexia is lifelong. The good news is that with systematic intervention to learn skills and compensatory strategies, dyslexics can and do learn to read, spell, and write.