Dyslexia in children and adults is often addressed according to two models, each of which generally focus on linguistic or language-related skills. “These methods emphasize strategy and cognitive development and are not based on a brain processing relationship, which is dysfunctional in dyslexia. Consequently, these techniques have not produced consistent reading improvement.” (Goldstein, 2001) Goldstein’s assessments still ring true today. Even so, many dyslexia treatment options tout an emphasis on “teaching” those with dyslexia words in a clearer way as if other reading educational efforts have somehow failed. The problem is, of course, that dyslexia is not necessarily a letter recognition problem, it is instead a cognitive processing problem. This means that dyslexia treatments based on language skills alone often fail.
One of the most common misconceptions about reading skills and acquisition of reading ability is that reading involves only a simple recognition of letters and subsequent knowledge of how to phonologically string those letters together into words. According to this simplistic model of reading, someone with dyslexia is simply not “seeing” the letters correctly, thus there is a perceived deficit in vision or sight. Although visual cues often play a role in the formation of dyslexia treatments, sight alone is only the tip of a very large iceberg. After all, when we see a sequence of letters, it has no meaning as an object until our brain, working as an integrated network of sensory systems, assigns significance to the abstract grouping of letters. Visual processing disorders, which are NOT related to the ability to see clearly, involve difficulties understanding visual information such as movement, spatial relationships, form, or direction. Such visual processing challenges, together with Central Auditory Processing problems, are frequently found in combination and result in a formal dyslexia diagnosis or poor academic performance.
However, the process is far more complicated on a cognitive level--mere recognition of words and sounds is only the first part in a long series of events that occur quickly and unconsciously in those without dyslexia but this process is “sidetracked” as the two hemispheres of the brain react differently than they would in non-dyslexic readers. Therefore, one of the fundamental flaws of traditional dyslexia treatment is that there is a heavy focus on teaching the words themselves while overlooking the fact that the problem lies in brain’s processing of letters as opposed to some kind of simple lack of understanding of letters, words and phonology.
A great deal of contemporary research focuses on the issue of brain processing in dyslexia treatment with multiple studies examining the delay or miscommunication between the left and right hemisphere of the brain, or problems with specific areas of the brain, including “planum temporal symmetry or angular gyrus dysfunction, that result in reading impairments and do not suggest developmental hemispheric changes as a rationale for dyslexia” (Goldstein 2001). While the results of these imaging-based studies continue to change our view of the cognitive and brain processing end of dyslexia treatment, one thing is clear—simply focusing on “teaching” those with dyslexia the letters or word sounds in a more focused way is simply inadequate. If the basic brain processes that govern the abstract meaning behind words and letters are not improved, then all of the phonics and letter training in the world will likely not solve the challenges that dyslexic readers face.
Source
Goldstein, B., & Obrzut, J. (2001). Neuropsychological Treatment of Dyslexia in the Classroom Setting. Journal of Learning Disabilities, 34(3), 276.
Dyslexia is a learning disorder that manifests itself as a difficulty with reading, spelling and in some cases mathematics. It is separate and distinct from reading difficulties resulting from other causes, such as a non-neurological deficiency with vision or hearing, or from poor or inadequate reading instruction. It is estimated that dyslexia affects between 5% and 12% of the U.S. population in some degree and is thought to be the result of a neurological defect/difference, and though not an intellectual disability, a language disability, among others. It is also worth noting that most dyslexics who have Boder's Dysiedetic type, have attentional and spatial difficulties which interfere with the reading acquisition process as well.
Visuospatial Cognition and Theories of Developmental Dyslexia:
When we look at a scene we feel that we perceive the visual world in all its detail and richness. This experienced quality and effortlessness of vision masks the fact that scene perception is actually a highly complex cognitive process, which requires the explorative scanning by eye movements, the quick and accurate direction of attention, the anticipation of the consequences of actions, and the integration and comparison of current visual input with stored representations of previously viewed parts of the scene and knowledge of objects and their relationships. A number of striking visual illusions demonstrate that scene perception is in fact a rather fragile process that essentially builds upon assumptions about the visual world to optimally piece together observations from a number of fields of scientific study.
The leading theories on the topic of developmental dyslexia should not be viewed as competing, but instead be seen as a complementary set of theories trying to explain the underlying causes of a similar set of symptoms but from a variety of research perspectives and backgrounds.
Here is a great link for information on the history and theories of developmental dyslexia.
Cerebellar Theory:
One such theory that has gained note in the past decade is represented by the automaticity/cerebellar theory of dyslexia. Here the biological claim is that the cerebellum of people with dyslexia is mildly dysfunctional and that a number of cognitive difficulties ensue from this dysfunction.
For many years, developmental dyslexia was thought to be a problem related to language itself. However, with the arrival of neuroimaging tools and greater research into the relationship between dyslexia and balance, among other things, opinions began to shift. It has become clear to researchers that developmental dyslexia and the cerebellum are somehow related due to the function of the cerebellum matching the deficits in function associated with developmental dyslexia.
The cerebellum, more than many other areas of the brain, is engaged in processing and deciphering a constant series of "behind the scenes" events. It is forever multitasking in the background of our conscious mind. It is responsible for the sequencing of input, the automatization of tasks and skills, as well as the production and interpretation of verbal and written language. Since developmental dyslexia is defined by problems in these three exact areas, the hypothesis that the cerebellum was responsible, especially when coupled with revelatory neuroimaging studies, has gathered strength and wide acceptance as a promising area of study.
The cerebellum plays a critical role in overall brain function but has particular importance in reading and writing tasks. “Impairments of the cerebellum cause deficits in motor control such as posture and balance, and additional difficulties in achieving ‘automaticity’ of other learned skills” including skills that are related to reading and writing. The complicated issue is deciding where and how there is a “misfire” among neural pathways—a task that can be almost impossible without the use of sophisticated imaging equipment over a long span.
Dyslexia Treatment:
While these problems seem difficult to overcome and detection of the exact location of the impairment may never be known, this does not mean there are not options for those with developmental dyslexia. In fact, cerebellar dysfunction as a theory does not imply a sentence for those with developmental dyslexia to a life of failed reading attempts. With concentrated effort on refining the neural pathways in the cerebellum, along with the sensory connections from the cerebellum to the other critical informational processing centers in the brain, the brain’s natural plasticity can be taken advantage of to establish better neuro-processing to help overcome developmental dyslexia as well as other processing-based learning difficulties.
Nothing about the brain is static. It is always on, always at work; sending, receiving, responding, interpreting. Accordingly, it is always handling input, although this input or the pathways it travels on may not be “optimized” for adequate processing. Neurological issues like these underlie learning challenges and indicate that specific disabilities like developmental dyslexia may be addressed simply… with vestibular-based brain training exercises like those available in the Learning Breakthrough Program.
Sources
Rochelle, K., & Talcott, J. (2006). Impaired balance in developmental dyslexia? A meta-analysis of the contending evidence. Journal of Child Psychology & Psychiatry, 47(11), 1159-1166.
Cyril R Pernet, Jean Baptiste Poline, Jean Francois Demonet and Guillaume A Rousselet: BMC Neuroscience (in press) – Brain classification reveals the right cerebellum as the best biomarker of dyslexia. http://www.biomedcentral.com/bmcneurosci/
