| |
The term dyslexia derives from the Greek for ‘difficulty with words and language’ and came into common usage in 1887, replacing the earlier, more emotive, phrase ‘word blindness’. Dyslexia is by no means a rare phenomenon, and although estimates vary, something of the order of ten per cent of people are affected.
Dyslexia can arise as a result of brain damage, either around the time of birth or possibly later in life, following a stroke. The pattern of dyslexia witnessed as a result of birth trauma is often compounded by hyperactivity, poor concentration and inherent clumsiness. However, this group of traumatized dyslexics are generally held to be in the minority, and the main focus of research has been a second group known as developmental dyslexics. Developmental dyslexia arises from a distinct pattern of neurological development which is almost certainly genetically determined. It is widely known that dyslexics experience difficulty in learning to read, but there are a number of underlying factors which contribute to this outcome. A major problem for some dyslexics is a general asymbolia, in which the ability to recognize words as coherent, symbolic entities is disturbed. The normal capacity to identify each word globally in terms of its symbolic value is impaired. Other symptoms include failure to perceive linguistic patterns such as intonation, stress and rhyme; disfluencies in the motor skills required for writing; difficulties in processing sound and letter sequences; short-term memory dysfunction in processing symbolic series; and even problems with spatial orientation and time judgements.
In most people, language is processed in the left hemisphere of the brain, in conjunction with analytic and symbolic skills such as the ability to manipulate numbers. Consequently, the problems experienced by dyslexics can sometimes be traced to impaired left hemisphere functioning. In these cases, the right hemisphere skills, which include face recognition, emotional expression, visuo-spatial and integrative skills, can be highly developed in dyslexics. Thus, it is not uncommon to find dyslectic people succeeding in the fields of architecture, art, design, technology and so on.
In the majority of cases, there is by now an overwhelming body of evidence to implicate deep-seated neurological causes for dyslexia. However, educational psychologists have been signally reluctant to treat dyslexia as an inherited condition and, instead, factors external to the child have often been blamed. Low socioeconomic status, general social maladjustment and emotional disturbance and poor teaching methods have all been cited as causes for dyslexia. Very often, these views appear to be more politically than scientifically motivated, and unfortunately they have tended to hinder rather than advance the treatment of dyslexics. Acknowledging the underlying neurological causes of dyslexia can help in the early diagnosis of specific disorders and thus lead to the design and implementation of appropriate teaching programmes. For example, some dyslexic children are more proficient at processing information aurally, in terms of sound patterns, rather than visually. For such children, a typical programme might concentrate on games involving sound patterns, rhyme, repetition, recitation and so on. In other words, the child\'s individual skills are exploited as a means of overcoming the language difficulties created by dyslexia. MS
Further reading F.R. Vellutino, Dyslexia: Theory and Research. |
|
