A Discussion of the Research on Dyslexia and Implications for the Classroom
Research has determined that observable differences in brain structure and function exist in the brains of those with dyslexia. Though I found some of the explanations complex, generally speaking, I understand that in the dyslexic brain, the magnocellular system, or pathway, functions differently. It is made up of large cells which carry out fast visual processes and appears disorganized with groups of smaller cell bodies than the magnocellular system in non-dyslexic brains. These disorganized bunches of cells and nerve fibers are called ectopias (“ectopic” meaning abnormal position). Scientists believe that ectopias occur in the developing brain of the fetus before its sixth month, and this belief coupled with the observation that dyslexia often runs in families, leads to the belief that genetic differences affecting early brain development cause ectopias. The differences in the magnocellular system may cause interference with the rapid processing required for changing visual signals such as those involved in reading changes in the cortex. Interestingly, the system that performs slower visual processes, the parvocellular system, is similar in both types of brains.
In addition, researchers have discovered a cortex difference. The planum temporale, an auditory region that is part of the language network, is typically larger on the left side of the brain, and it is believed that the asymmetric brain design provides for efficient processing of sequential information and for learning certain language skills, including reading, writing, and spelling. Studies show that the planum temporale is the same size in both sides of dyslexic brains. In other words, dyslexic brains are more symmetrical. Symmetry of this area may interfere with learning to read and write.
The primary similarity between the brain of the dyslexic and the non-dyslexic is that in both the brain of the dyslexic and of the non dyslexic, processing activity occurs in Broca’s area, though to varying degrees; a key difference is that activity is also occurring in the Parieto-temporal and Occipito-temporal regions of the non dyslexic brain. Even when subjects used the same brain regions that non-impaired readers typically use, the time it took for different areas to become activated, as well as the order in which they became active, was still noted to be different.
The purpose of most research on dyslexia is to establish the entire chain of causal links between certain genes, certain parts of the brain, certain cognitive functions, and the ability to read and write; Gordan Sherman emphasizes that no two brains are alike, with variations of variations among brains (Sherman & Cowen, 2003).
Sherman defines cerebrodiversity as “the collective neural heterogeneity of humans as well as individual neurocognitive profiles of strengths and weaknesses,” and then continues the explanation with this fantastic sentence: “the underlying neural design may embody wonderful even pivotal possibilities” (Sherman & Cowen, 2003). The idea behind cerebrodiversity, and that I completely agree with, is that we want to view dyslexia in a larger context and understand the implications beyond its negative impacts. I enjoyed reading about this idea in other publications and found Sherman’s and Cowen’s (2010) discussion of Geschwind and his work really interesting. They write that Geschwind “often spoke and wrote about – what he called ‘the advantages of the predisposition to dyslexia’ or ‘the pathology of superiority” (Sherman & Cowen, 2010, p. 14). Sherman explains this as the brain developing in a subtly different way, but not in a deficient way, and that the negative impacts of this difference play out in the context of learning to read. He believes that in other contexts, this negative consequence might almost be considered negligible, but the fact is that we operate in a society that not only values literacy, but demands it. Sherman states that this conflict between what society demands and how the dyslexic brain processes is due to how reading is taught — or more accurately, how it is not taught. Sherman says that “for the most part we do not teach reading in ways that play to the strengths of people with dyslexia” (Sherman & Cowen, 2003).
So what are these strengths? I wanted to learn more so I kept reading. I learned that a British neurologist named Macdonald Critchley, who personally examined more than 1,300 patients with dyslexia, found that “a great many” of these patients had shown exceptional abilities in spatial, mechanical, artistic, and manual activities, and that they often pursued occupations in these areas of strength (Eide, 2011, p56). In his book Thinking Like Einstein, author Thomas G. West shares a conversation with dyslexic computer graphic artist Valerie Delahaye, who specializes in creating computer graphic simulations for movies. She told him that at least half the graphic artists she’s worked with on major projects like Titanic and The Fifth Element were also dyslexic. I actually laughed out loud when I read that West also quotes MIT Media Lab founder and dyslexic Nicholas Negroponte as stating that “dyslexia is so common at MIT that it’s known locally as the ‘MIT disease’” (Eide, 2011, p55). I had fun sharing these findings with a student today – he told me that indeed his ability to mentally visualize 3 dimensional spaces, objects, angles, and trajectories gives him a definite advantage on the hockey rink.
As Sherman points out, it’s all about context and I agree that this view helps us move beyond the disability mindset. We need to view dyslexia as “a dynamic gene-brain-environment interplay” that “yields tiny neural differences (anatomical, cellular, and connectional) that, depending on environmental demand, can translate into socially defined talents and disabilities” (Sherman & Cowen, 2003). For example, one may have “strength in the big-picture reasoning needed to combine multiple perspectives into a complex, global, interconnected, 3-D model of a virtual house” while struggling with memory and processing of fine details: this shows “the pattern of trade-offs” (Eide, 2011, p52). Geschwind (2010) put it succinctly: “Context determines advantage versus disadvantage.”
With this in mind, teaching matters, and clearly we need a paradigm shift among classroom teachers regarding delivery methods, assessment procedures, and reasons for what is being taught. As Sherman asserts, “We must understand the complex interplay between unique brain designs, environmental variables, and resulting learning differences” (Sherman & Cowen, 2003). We have overlooked the significance of environment and thus missed recognizing the elements of effective reading instruction and the part played by ineffective reading instruction in general education classrooms. What have resulted are misdiagnosis or missed diagnoses, inadequate interventions, and frustrated students, parents, and teachers. I thought it interesting that it’s been noted that the IDA took this into consideration when revising the definition of dyslexia as (underlining mine for emphasis):
“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.” (IDA, 2007)
Implied here is that if there is not effective classroom instruction then these difficulties are expected in the classroom.
When Sherman discussed this, he used the word “contaminated” to describe the impact on research into the prevalence of learning disabilities and in particular, estimates of developmental dyslexia; that is a loaded word, carrying much more connotative significance than other words he might have used such as “skewed” or “influenced” or even “distorted”! As a result of Sherman’s work and the work of others, it is clear that children with the following weaknesses or deficits are not adequately identified, understood, or helped:
- executive/metacognitive skills such as setting goals, initiating, monitoring behavior, organizing, planning, anticipating, and adapting
- social communication skills
- adaptive functioning in predictably challenging environments, such as adopted status and socioeconomic disadvantage (Dickman, 2008)
We need to have a better understanding of the complexities and the inter-relationships of genetic factors, brain differences, and environmental influences because “things are as they are because of their relationships with everything else. You can’t just look at anything in isolation.” (Eide, 2011, p79).
For this reason, teaching matters; more accurately: appropriate, purposeful, research-based teaching matters.
All this leads to the belief that we must weigh the risk of altering programs now in place to provide help to students with dyslexia vs. the risk of doing nothing at all in terms of change. As Sherman cautions, this does not mean throwing out the “disability model” — it is valid in some contexts, and we recognize that literacy is and will continue to be integral to the lives of individuals (Sherman & Cowen, 2003). The fact that we all value literacy and want the best for our students’ lives in and beyond the classroom is the binding similarity that keeps many striving for change and improvement through organizations such as IDA. What we need to do is ensure evidence-based instruction in every classroom.
As I thought about this, I contemplated what this would look like in the general classroom here in southern California, in both public and private institutions. Here’s what I see:
- assistive technology the norm in the general education classroom as a means of enhancing instruction and learning for all students (not yet in our local public schools)
- all content delivered in multiple ways using multiple modalities (increasing in our public schools)
- emphasis on quality of instruction over coverage of content (depends on the school’s overall test scores)
- emphasis on training teachers to recognize signs of dyslexia and how to effectively teach phonological awareness in the general education classroom (still a weakness in credentialing programs, in my opinion, and limited in scope in public schools due to funding issues)
I know I should conclude with my own words, but the following quote sums up the topic so much better than I can:
“The unexpected consequence of attempts to standardize educational practices has been to handcuff our educators, stifle creativity, create conflict and competition between general education and special education, and deny our children access to meaningful early intervention. If the system is indeed ‘broken,’ as seems to be the political consensus, then the injury is self inflicted. In this case top down problems need bottom up solutions. We must reject that which is ineffective and immoral and we must demand the knowledge, training, and freedom to be effective. The “we” of whom I speak is parent, advocate, teacher, principal, and everyone who is in the position to see, touch, and influence the life of a child” (Dickman, 2008).
Dickman, G. Emerson. “Roads Less Traveled,” Perspectives on Language and Literacy, Fall 2008, 5, http://www.questia.com/read/1P3-1639897981
Eide M.D. M.A., Brock L.; M.D., Fernette F. Eide (2011-08-18). The Dyslexic Advantage: Unlocking the Hidden Potential of the Dyslexic Brain. Penguin Group US. Kindle Edition.
Geschwind, Norman. “Pathology of Superiority: A Predisposition to Dyslexia May Have Advantages,” Perspectives on Language and Literacy, Winter 2010, http://www.questia.com/read/1P3-1995238211
IDA web site: http://www.interdys.org/FAQWhatIs.htm
Sherman, Gordon F. and Cowen, Carolyn D. “Neuroanatomy of Dyslexia Through the Lens of Cerebrodiversity,” Perspectives on Language and Literacy, Spring 2003,
Sherman, Gordon F. and Cowen, Carolyn D. “Norman Geschwind: A Man out of Time,” Perspectives on Language and Literacy, Winter 2010, 14, http://www.questia.com/read/1P3-1995238201