Minnesota state statutes define dyslexia as the following:
125A.01. Subd. 2. "Dyslexia" means a specific learning disability that is neurological in origin. It is characterized by difficulties with accurate or fluent recognition of words 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 the growth of vocabulary and background knowledge.
According to the National Center for Education Statistics and National Institutes of Health, 33% of students served under the Individuals with Disabilities Act have a specific learning disability. In relation to the entire population, 15% of the US population (or 1 in 7 students) has a learning disability. Of students with a specific learning disability, approximately 80% have reading problems. This means reading problems are the most common type of learning disability. The prevalence of dyslexia is likely between 5%-10% (Catts et al. 2005; Shaywitz et al., 1990) with a more catchall range being 5%-17% of students (Shaywitz & Shaywitz, 2003). Prevalence is highly dependent on identification criteria, and the criteria for dyslexia tends to be more inclusive than the criteria for a learning disability category within the Individuals with Disability Education Act which provides special education services to eligible students.
The state statute ties the definition of dyslexia to the criteria of a specific learning disability and narrows it to characteristics of difficulties associated with accurate or fluent recognition of words and by poor spelling and decoding abilities.
General Symptoms of Dyslexia:
Difficulty recognizing letters and sounds automatically (quickly and accurately)
Difficulty decoding words (i.e., sounding them out)
When educators teach reading, they are literally changing the way the brain is wired. This is because our student's brains haven't evolved to learn to read. However, because of the brain's neural plasticity, it can repurpose existing neural networks (Dehaene, 2009).
Simply put, there is no specific part of the brain dedicated to reading.
It's not a natural thing our brain's just start doing. When learning to read, the brain adapts for a new purpose. This adaptation occurs over time, so depending on where a student is in their reading development, the patterns in the brain are activated differently (Cunningham & Rose).
Within the brain, it is the left hemisphere that is associated with language comprehension, speech production, reading, and mathematical calculations (Ormrod, 2016).
This is the intentional decoding of a word, and it is slower and uses more mental capacity than sight recognition.
Students identify specific letters in a word.
Students convert those visual images into sounds and blend those sounds together into a word.
Students need to connect the word to meaning.
For the word bat, students (1) see the letters B, A, T, (2) convert the letters to sounds (/b/, /a/, /t/) and blend them together, and (3) connect the word bat to its correct meaning based on language comprehension (i.e., either a baseball bat or an animal bat).
The phonological path figure is a simplified version of the reading brain using the phonological path (based on the work of Dehaene, 2009 and Strom, 2022).
When a student reads a word in their sight word vocabulary as a result of orthographic mapping (i.e., permanent storage of a word in the brain), their brain follows the faster lexical path.
A faster neural pathway.
This pathway is faster and uses less mental capacity because the brain’s letterbox, which develops in the visual areas of the brain, is specialized for recognizing specific strings of letters (i.e., words). Once a student sees a word (or a specific string of letters) that has been stored in their letterbox, both sound and meaning are quickly activated in the brain.
For some students, this quick recognition occurs after only a few exposures to the word. For other students, it may take many more exposures.
The lexical path figure is a simplified version of the reading brain using the lexical path (based on the work of Dehaene, 2009 and Strom, 2022).
Because of brain plasticity, deliberate and intense instruction can strengthen the appropriate neural pathways for reading or create bypasses around problem areas (Cunningham & Rose; Eden, 2016; Krafnick et al., 2011; Simos et al., 2002). Simos et al. (2002) showed that after a sufficiently intensive intervention, functional brain deficits underlying dyslexia can be reversed. Other studies have shown that this brain “normalization” occurs when intervention is early, intensive, and effectively designed (Blachman et al., 2004; Simos et al., 2007). These studies propose that reading difficulties are but a variation from normal develop that can be alternated by intensive intervention (Simos et al., 2002). Any students that do not respond will likely be eligible for special education services and in need of intensive, on-going support to overcome a severe reading disability. Lastly, while it is debatable that dyslexia can be truly “cured,” the only way to overcome the deficits associated with dyslexia is to teach students how to read. To overcome dyslexia, learning to read will require significantly more effort and support, but, nonetheless, they can learn to read.