Most children look forward to learning to read and, in fact, do so quickly. For dyslexic children, however, the experience is very different: For them, reading, which seems to come effortlessly for everyone else, appears to be beyond their grasp.
The process whereby they learn to transform what are essentially abstract squiggles on a page into meaningful letters, then sounds, then words, and then entire sentences and paragraphs, seems to be an impossible task. They grow frustrated and disappointed. Teachers wonder what they or the child might be doing wrong, often misdiagnosing the problem or getting bad advice. Parents question themselves, feeling alternately guilty and angry.
What is dyslexia?
The DSM-5 (American Psychiatric Association, 2013) uses the term ‘Specific Learning Disorder with impairment in reading’ to describe what others call dyslexia. It considers dyslexia “specific” for four reasons: it is not attributable to
- an intellectual disability, generally estimated by an IQ score of 65-75;
- a global developmental delay;
- hearing or vision disorders; or
- neurological or motor disorders.
What is the main problem in dyslexia?
It is widely agreed that the core problem of dyslexia is a difficulty in decoding text. To decode a word, you need to know:
- Which sound or sounds each letter makes, like how a c sounds in cat and how it sounds in cent.
- How to take apart the sounds in a word and blend them. For example, with jam, the first sound is /j/, the next sound is /ă/, and the last sound is /m/. Then slowly blend them in “jjjaamm.”
- How groups of letters can work together to make a single sound, like ph in phone.
Decoding relies on the rules of phonics. Most words in the English language follow those rules. But some words don’t. For example, if kids try to sound out the word of, they might pronounce it “off.” Or they might try to spell it “uv.”
There are, however, many other symptoms, and there are many reasons why a child would struggle with decoding.
How do decoding difficulties manifest in reading?
You may be seeing signs of trouble with decoding if kids often:
- Use the first sound or two to guess what a word is, like saying sun when the story says songs.
- Use context to try to guess what a word is, like seeing a drawing of a building and the word house but guessing that the story says home.
- Read very slowly because it takes a long time to blend the letter-sounds together.
- Have trouble understanding or remembering what’s read because it takes so much time and effort to figure out each word.
How percentage of the population has dyslexia?
Depending on the definition and diagnostic criteria employed, dyslexia affects from 3% to 20% of the population (Elliott & Grigorenko, 2014; Lallier et al., 2018; Shaywitz, 2005), and up to 40% experience some type of reading difficulty (Mather & Wendling, 2012).
What are the different types of dyslexia?
There are three main types of dyslexia in children: dyseidetic, dysphonetic and dysphoneidetic dyslexia.
- The prominent characteristic of dyseidetic dyslexia is the inability to revisualize the gestalt of words. Common symptoms include confusion with letters that differ in orientation (b-d, p-q), very limited sight vocabulary, losing the place because one doesn’t instantly recognize what had already been read, and difficulty learning irregular words that can’t be sounded out.
- Dysphonetic dyslexia is associated with phonological and auditory processing difficulties. These children have difficulty remembering letter sounds, analyzing the individual sounds in words, and sequencing/blending these into words.
- Mixed dyslexia or dysphoneidetic dyslexia is when a child struggles with both.
In their article, “Types of developmental dyslexia,” Friedmann and Coltheart (2918) distinquish between nine types. According to some scholars, however, research does not support the use of dyslexia subtypes to guide assessment and intervention (Peterson et al., 2014).
Is there an at-home dyslexia test?
In many countries, the ability to diagnose dyslexia is limited to certain qualified professionals and an extensive evaluation. This evaluation looks at a child’s ability to read, in addition to other factors such as general academic ability and family background. Typically, a large amount of information is required and the person administering the evaluation or assessment will take the child through a series of tests. This thoroughness is necessary, because it’s important to rule out other possibilities.
References and sources:
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596
Elliott, J. G., & Grigorenko, E. L. (2014). The dyslexia debate. Cambridge: Cambridge University Press.
Friedmann, N., & Coltheart, M. (2018). Types of developmental dyslexia. In A. Bar-On, & D. Ravid (Eds.), Handbook of communication disorders: Theoretical, empirical, and applied linguistics perspectives. Berlin, Boston: De Gruyter Mouton.
Lallier, M., Lizarazu, M., Molinaro, N., Bourguignon, M., Ríos-López, P., & Carreiras, M. (2018). From auditory rhythm processing to grapheme-to-phoneme conversion: How neural oscillations can shed light on developmental dyslexia. In T. Lachmann, & T. Weis (Eds.). Reading and dyslexia (pp. 141-157). Cham, Switzerland: Springer.
Mather, N., & Wendling, B. J. (2012). Essentials of dyslexia assessment and intervention. Hoboken, NJ: Wiley.
Peterson, R. L., Pennington, B. F., Olson, R. K., & Wadsworth, S. (2014). Longitudinal stability of phonological and surface subtypes of developmental dyslexia. Scientific Studies of Reading, 18, 347-362.
Shaywitz, S. (2005). Overcoming dyslexia: A new and complete science-based program for reading problems at any level. New York: Vintage Books.