Bsc Hons Dissertation for Glasgow Caledonian University

"The Suitability and Effectiveness of Voice Recognition Software
for Dyslexic Users"

There are patterns which have been discovered in the hundreds of studies undertaken throughout the years which have identified more than just one form of dyslexia -

Developmental Dyslexia (DD) is defined by the World Federation of Neurology as "A disorder manifested by difficulty in learning to read despite conventional instruction, adequate intelligence and socio-cultural opportunity". (Brosnan, et al 2002 - p1) It has generally been well accepted in recent years, that one of the main causes could be a phonological deficit - the inability to recognise certain speech sounds and turn them into written language - and vice versa. Other areas of research, studying brain activity in particular suggest that there could be a deficiency in the cerebellum, the area of the brain that controls balance, (Nicolson, et al, 2001).

This would seem to explain why some dyslexics have problems with co-ordination and balance, or display symptoms of 'motion-sickness' when reading for lengthy periods. These diagnoses have come as a great relief to dyslexics to know that it is a tangible physical condition and that they are not 'stupid' or 'thick', as was previously widely thought.

An international study also supports the claim that there is a Dyslexia Gene, (Fagerheim, 1999) which tested large numbers of people from the same families and discovered that a high percentage were dyslexic. Out of one Norwegian family of 30 tested, 11 were found to be dyslexic. Further investigation seems to support this claim, as many dyslexics contacted during this study have parents, siblings or other close relatives who are also affected.
Orton, during his many studies throughout the 1930's and 40's also confirmed the physiological aspect, stating that it could run in families, and that it was also more commonly found in boys than in girls.

According to Johnston and Myklebust (1967), Developmental Dyslexia can be further broken down into sub-types of Visual and Auditory Dyslexia. They make the distinction that those with Visual Dyslexia can identify what words or letters sound like, but cannot make a connection with their appearance, while with Auditory Dyslexia, it works the opposite way - they can learn the words and what they look like, but cannot relate these images to the way they sound. This distinction seems to help clarify why some Dyslexics can be very creative writers, such as Hans Christian Andersen - one of the greatest children's storytellers, even though he could not spell properly (Aaron, et al, 1988). While other dyslexics will avoid reading and writing at all costs.

Acquired Dyslexia occurs when the nerves within the brain, which deal with communication processing, are damaged in some way, such as after some sort of injury, like an accidental head trauma, haemorrhage, or stoke.

One particular case study (Gottfried, et al, 2002) shows how a 51-year-old woman began persistently mirror-image reading and writing, only after having suffered a traumatic brain injury. This was, however an isolated case and does not suggest in any way that those who suffer brain trauma will develop dyslexia.

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