So What EXACTLY is Dyslexia? (Part II)

Originally published here on June 4, 2008.

(Read Part I.)

Below you will find a few of the more popular, formal definitions for dyslexia:

• According to the British Dyslexia Association dyslexia is "a combination of abilities and difficulties that affect the learning process in one or more of reading, spelling, writing. Accompanying weaknesses may be identified in areas of speed of processing, short-term memory, sequencing and organisation, auditory and/or visual perception, spoken language and motor skills. It is particularly related to mastering and using written language, which may include alphabetic, numeric and musical notation."


• The National Institute of Neurological Disorders and Strokes says that dyslexia is "a brain-based type of learning disability that specifically impairs a person's ability to read. These individuals typically read at levels significantly lower than expected despite having normal intelligence. Although the disorder varies from person to person, common characteristics among people with dyslexia are difficulty with phonological processing (the manipulation of sounds) and/or rapid visual-verbal responding.


• The International Dyslexia Association says that dyslexia "is a language-based learning disability. Dyslexia refers to a cluster of symptoms, which result in people having difficulties with specific language skills, particularly reading. Students with dyslexia usually experience difficulties with other language skills such as spelling, writing, and pronouncing words. Dyslexia affects individuals throughout their lives; however, its impact can change at different stages in a person’s life. It is referred to as a learning disability because dyslexia can make it very difficult for a student to succeed academically in the typical instructional environment, and in its more severe forms, will qualify a student for special education, special accommodations, or extra support services."

The definitions have some common threads. The IDA's definition seems gear toward asserting the legal status of dyslexia as a educational disability. All three definitions are broad and general. And none are particularly clinical in the sense of providing much criteria for testing or for distinguishing people who have some of the symptoms but are not dyslexics from people who are dyslexics.

So now I'll return to my conversation recently on the International Reading Association's listserv for reading teachers. Hugo Kerr put forward a proposed definition for dyslexia as part of that discussion. I think the definition comes from his new book, but I haven't finished it yet. Hugo's definition is

An innate, neurological condition specifically disabling the acquisition and use of literacy.

You can find it here in a post he wrote to the Reading Teachers list, hosted by the International Reading Association. (You can read posts from the larger discussion here, in the archives of that listserv on the IRA's site.)

If you contrast Hugo's definition to the three put forth at the beginning of Part II here, it has some advantages and disadvantages. On the one hand, it is more concise, more portable than any of the three definitions we started this piece with. The phrase "the acquisition and use of literacy" keeps us from having to specify particular problem areas and covers things that might be involved in literacy even though research hasn't discovered them yet.

Two words make the definition difficult to deal with. The first is innate. I'm not sure it's clear to us what is and what is not innate in humans yet. I know what the word means. I just don't know how we measure it. How do we determine whether a particular behavior is innate - especially if it is a behavior that emerges after birth during some developmental stage.

The second problem word for me is specifically. From discussions with Hugo on the listserv, he seems to me to feel that the problems commonly called dyslexia will eventually be attributed to disorders that don't primarily have to do with literacy. Hugo doubts that we'll ever identify a neurological disorder that specifically affects literacy. In fact, he has said repeatedly that he doesn't believe in dyslexia (for example here, in the listserv post from the IRA's site).

So why write a definition for something you don't believe in? My conclusion is that Hugo's definition is so narrow in order to define dyslexia out of existence. The definition is in itself a tool for helping to promote the idea that dyslexia doesn't really exist.

Does dyslexia exist? I'm not sure. I do know that it is a persistent concept. Over a century of work on the idea hasn't killed it yet. And I know that brain science is a relatively young field in light of the explosion of technology in the last 25 years.

As someone who provides reading interventions in an elementary school, my primary concern is with what prevents reading. Whether reading failure is the primary cause of some brain problem or is more secondary, the growing importance of literacy in our society probably makes literacy the most important area of impact.

One of the most common complaints about dyslexia research is that the definition is so poor. How do we know what we're testing for in an experiment? Hugo is among those who complain about that problem. Shoddy research: that's the accusation. The difficulty with that is that with the advances that have taken place in technology (and therefore in the types of data we can collect) we don't seem to be sure what we're looking for at the moment. The research is exploratory, and hopefully well soon know enough to design better research. That's how science works.

One thing that will not happen: we will never arrive at some final conclusion about dyslexia, one that allows us to simply say, "so there you have it." That's not how science works.

Want to know exactly what dyslexia is? Ask me again in 10 or 15 years...

Phonemes and the Construction of Reality

Originally published here on March 4, 2008.

Before they have words in their heads, before the speech of others has semantic content for them, toddlers begin to parse up the sounds they hear and create categories in their minds. We call those cognitive categories phonemes.

Phonemes are one of the clearest examples of how we take the world around us and building chunks of meaning for ourselves. Call that "reality" if you want. It is, in a sense. It's our reality, at least. I'd rather say we build our own meaning to attach to reality, but whatever. Same thing...

One of the easiest ways to explain how we class sounds (vibrations of the air that have physical properties and can be measured with a machine) into phonemes is to look at the phoneme we usually call "L."



"L" is not a sound, it's an idea - an idea about how to group all the sounds together that you call “L” – different sounds that together make up “L” in your mind.

I know what you're probably thinking: “What do you mean? L is L.” And I have to say, “Not really.”

I explained it somewhere else like this:

Think about it for a moment. When you say “like,” you take the tip of your tongue and press it fairly hard against the back of your two top front teeth and you spread your tongue out like it was a hammock inside your mouth. When you say “full,” your tongue may not touch your front teeth at all; instead of spreading it out, you bunch it up in a ball in the back of your mouth and maybe the tip of it rests gently on the bony ridge you have behind your top teeth. You make a different sound at the beginning of “like” than at the end of “pull,” but you call both of them “L” if you speak English, because English speakers group them together as one phoneme.

Doesn’t everybody do that? No. In Russian those two sounds each get their own letter. You can put the “L” in “pull” at the beginning of Russian words and the “L” in “like” at the end of Russian words.

That's how it works. You group sounds together and (eventually) give them a name.

A couple of thoughts...

First, don't we all build the same reality? An "L" for you is an "L" for me, right? So how is that Constructivist? Well the answer to that is that we pretty much all build the same reality here, in our little piece of Appalachia. But if we were Russian (or Japanese or Korean), the reality we'd build would most likely be different from Appalachian reality. The fact that, as a group our different "realities" look a lot alike lends weight to the ideas of Lev Vygotsky and the Social Constructivists. They thought that constructing reality was a social activity.

Second, if you're dyslexic you probably have problems with phonemic awareness. You might build the phonemes in your head just like the next kid (which is why you can talk and understand people), but you have problems recognizing them as such. And that means that the next layer of your reality (which has to do with reading) is a little different from the reality of the other kids around you...