What do Academics Agree on and Where Are the Differences?

There is wide consensus that dyslexia is underpinned by differences in the brain, leading to variations in how the information relayed by the senses to the brain is cognitively processed. For instance, someone suffering from dyslexia may face difficulties in processing such information, to a greater or lesser degree. In terms of reading and writing, these differences can lead to a learning disability. Research on the magnocellular system has resulted in some agreement that dyslexia may be caused by a more general cognitive deficit in timing. It is possible that this will affect all brain functions, including visual, phonological and kinetic functions.

There is agreement among some researchers that there may be physiological grounds for cases of dyslexia and as a result, MRI brain imaging techniques would be useful for consideration in future (Vandermosten et al., 2012). Although there are many potential underlying causes and difficulties associated with phonological processing is the best understood cause for dyslexia, neuroimaging methods are also significantly contributing to knowledge about the neurobiology of dyslexia (Norton et al., 2015).

There are various angles from which difficulties at cognitive level are explained by neurological variation. One view is that individuals with dyslexia may have deficits in different areas of the brain. For some theorists, the main focus is on addressing problems of phonological processing and speech difficulties, with regard to reading, spelling and naming, alongside other phonological functions. On the other hand, some researchers highlight the occurrence of difficulties with processing and a ‘syndrome’, often resulting from attempts at analysis, of symptoms occurring at behavioural level; for example, the work of Miles (1993). In more recent times, the phonological deficit hypothesis has become the basis of agreement amongst the majority of researchers in the field of dyslexia (Snowling, 2000; Vellutino et al., 2004). However, some claim that individuals currently suffering from dyslexia face difficulties across a broad spectrum, including visual processing deficits (Vellutino et al., 2004; Chouake et al., 2012). In fact, some would argue that difficulties with visual processing have greater significance than phonological problems.

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More often, it is stated that phonological dyslexia and surface dyslexia are two types of dyslexia which are acquired. Those who suffer from phonological dyslexia may find it difficult to decipher words, while those with surface dyslexia may experience difficulty in recognising visual vocabulary. Nevertheless, Miles and Miles (1999) disagree with the notion that the same sub-type will automatically persist throughout every stage of a person’s life. As suggested by several researchers, for example, Ellis (1993), the perceived differences involve individual compensatory approaches, rather than variations in underlying impairment. According to Fawcett and Nicholson (2001), it is predicted that subtypes of dyslexia may be due to inability or fundamental differences in brain function. It is therefore possible that future research will unveil magnocellular, cerebellum and other mixed sub-types; each linked with a different set of skills. In further research, the impact of magnocellular and cerebellum systems on sub-types will be highlighted.

At the same time, educators should be very sensitive when dealing with different approaches to dyslexia - some of which may be more complicated than others. It is worth highlighting the importance of avoiding looking at dyslexia as merely representing difficulty with reading and writing. It must also be understood, for example, that aspects of motor and organisational skills may be affected. Moreover, the view that individuals with dyslexia have a gifted side is an ongoing bone of contention. A great deal of research has been carried out on the weaknesses produced by dyslexia, but studies on their strengths are still few and far between, with a number of these drawing upon personal histories (Rack et al, 2007; Everatt et al., 2008; Glazzard, 2012). However, this approach could be seen as very positive, because it involves listening to the voices of those directly involved. On the other hand, more research may be necessary to generate overwhelming evidence proving there is a strong and stable relationship between dyslexia and creative visual thinking, in order to support the idea that the brains of individuals with dyslexia merely function differently.

Studies have in fact shown that although the brains of non-dyslexics tend not to be symmetrical (being larger on the left), the brains of individuals with dyslexia may show some symmetry, because the right hemisphere endeavours to compensate for the skills deficit in reading. Therefore, there may be significant development in parts of the brain which control, for example, visual and spatial skills, which do not depend on language. In fact, this is particularly relevant to visual and spatial skills (Krupska & Klein, 1995). Nevertheless, the assumption that learners with a tendency to process information in the right hemisphere of the brain will have better visual skills is yet to be conclusively proven.

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The above debate would be significantly enhanced by further research on the magnocellular and parvocellular systems of persons with dyslexia (Stein, 2001); even though some critics believe that the strengths of such individuals may be due to environmental influences. The early failure of children with dyslexia in school may force them to look for opportunities to achieve success in other areas, while literacy problems may lead them to find unconventional ways and thinking strategies to deal with their difficulties. Artistic gifts can be distributed evenly among the population, but it seems more pronounced among individuals with dyslexia, as their creativity is confined to non-verbal areas. It is important to mention that no two persons with dyslexia are the same and there is no evidence that all individuals who suffer from dyslexia exhibit the same qualities. According to the definition applied, estimates of dyslexia occurrence will vary. It has been found by some that there are more male than female dyslexia sufferers, although this can be challenged, given that different criteria have been used across such studies (Miles & Miles, 1999). It may also be stated that dyslexia affects both sexes equally, but if there are fewer or no females identified, it could be because women compensate for the deficits more than men, due to differences in the way they process language. There are still other researchers who claim that in general, girls tend to seek less attention than their peers of the opposite sex and are therefore more likely to have their problems overlooked at school (Riddick, 2006).