Phonological Theory of Dyslexia
Learning difficulties have been a common occurrence and there are many theories established to explain this disorder. Dyslexia, the common term for learning problems, affects a large part of the population and several studies have been carried out to determine the main cause of the disorder. Psychologists have been engaged in debate as to what theory best describes the occurrence of dyslexia with support for either of the three dominant theories of developmental dyslexia namely; the phonological deficit theory, cerebellar theory or the magnocellular theory. The phonological deficit theory has received greater support among most practitioners and this study will look into the support provided for this theory as well as reasons for its opposition. Specifically, the study will dwell on the neurobiological aspect of the theory and gaps that have not been answered by previous studies. Phonological (deficit) Theory
This theory is based on the idea that learning is based on word pronunciation. This means that a person who suffers from the inability to pronounce sounds correctly will have a reading problem as such a person cannot be able to associate a word with sounds (Ramus, et al., 2003). The general assumption in this theory is that phonetics is the basic unit of learning and when it is impaired, then a student or learner is subject to learning difficulties. Various scholars have supported this theory as an explanation to the occurrence of dyslexia in including Ramus, et al (2003) who, in their study, suggested that phonological disorders were most common in people with learning difficulties. The authors show that learning is affected by the ability to comprehend the sounds associated with words (Ramus, et al., 2003; Castles & Coltheart, 2004). In addition, the authors conducted a study that examined dyslexic students on their ability to learn through naming and other methods. Their results clearly showed that there was inability to associate words with sounds and hence the increased difficulty among the subjects. Snowling (2008), though not providing direct support for the phonological theory, shows that children with impaired reading capabilities had suffered from phonological impairment. In her study, Snowling (2008) found that 6-year-old children who were considered at risk had phonetic problems. The control group outperformed all children considered prone to reading disorders. This study showed that problems in associating sounds and words were factors in dyslexia. Further studies by the same author showed that phonological problems were not the only causes of dyslexia but they played a vital role (Snowling, 2008). Some words that have similar pronunciation but different meaning or words rhyme when pronounced. According to Goswami (2003), such words have been observed to cause difficulty in learners with dyslexia. In addition, such learners also exhibit inability to retain spoken words such that a learner cannot repeat what he/she has heard. The author also states that improving phonological ability in learners leads to improved learning capability (Goswami, 2003). As such, this study has outlined a clear basis for supporting the phonological theory. When learners gain the ability to remember speech, they are better able to develop reading skills since there is deep association between sound and reading (Joly-Pottuz, Mercier, Leynaud, & Habib, 2008). Most languages have shown that developing a strong phonological ability increases the ability of a person to learn the language (Blau, et al., 2010). In addition, most languages express themselves on phonological form hence the association between reading and speaking (Kovelman, et al., 2011). It is without doubt that the brain is the single most important organ when it comes to the development of a person. As...