Reading is one of the most important tools for adapting to the social and educational contexts. A failure in learning this will quickly generate a series of negative effects on the child, like a negative attitude, grade repetition, dropout and, ultimately, the association of learning with anguish and a feeling of incompetency with regard to a task.
Speaking is made of sounds; these sounds are called phonemes, and are classified in consonants, vowels, consonant clusters and diphthongs.
Learning to read and write requests that one have the cognitive resources that will help them associate in their mind the sound, or phoneme, with the corresponding graphic or visual symbol, called grapheme. This implies that the person can recognize the letters and groups of letters, so that they can understand what that word means.
However, this process that seems so trivial and that is carried out almost automatically, is the cause of much grief and difficulties for some children.
There is a group of difficulties in the development of language that are not sufficiently explained by impaired auditory perception or a faulty phono-articulatory apparatus, nor by intellectual retardation or other psycho-patological disorders and socio-emotional deprivation. These disorders are grouped under the name “specific developmental language disorder” (SDLD) and are subject to different clinical procedures, depending on the level to which the phonological, syntactical and lexical capacities are affected, with regard to comprehension and expression. These can, in turn, be associated with communication disorders (autism) or with a background of learning disorders, like dyslexia or dysorthographia.
The dyslexic-dysorthographic child is biologically different, because he has a special genetic component that formed his perception of the world before any formal learning did. According to recent studies, the origin of this is in the brain, so he is different from birth; therefore, when the time comes to teach him how to read, he has already interacted with his environment differently than the others. From the first words, his mother tongue has been perceived by his brain in a different way. From the first contacts with his visual environment, the image that he makes in his mind about the surrounding world and his perceptions about time and space are different, too.
The development of neuropsychology allowed us to discover that the brain of a child, as well as that of an adult, is organized in a modular way; that is to say, it consists of interconnected networks, each one commanding a different part of the intellectual process. The well-functioning of each of these networks can be damaged in at least two ways: either by suffering a lesion, an injury close to a cerebral area (like, for instance, a serious head trauma), or due to the fact that the respective area has developed incorrectly from the first moments of life in-womb, or from birth.
In both cases, the consequences are usually the same. When the damaged networks need to be used for an intricate activity like reading, the person faces specific reading difficulties, thus matching the general term of dyslexia. When dyslexia appears at an adult who has previously learnt how to read properly, it is called acquired dyslexia (or alexia). But when the condition is present before reaching the age appropriate for learning how to read, then it is the learning that will be perturbed, so then we talk about developmental dyslexia.
What happens in the brain of a dyslexic child?
The human brain consists in two hemispheres – right and left – that communicate with each other through a structure that acts as a bridge between them, called corpus callosum (the colossal commissure).
Each hemisphere specializes in several functions. The left hemisphere controls the language processes, while the right one handles processes concerning visual and spatial information.
The two cerebral hemispheres function differently; the left one processes the information sequentially, some data after the other, while the other one does this simultaneously – that is, a great amount of data at the same time.
In reading, the two types of strategies are combined in order to manage the information. However, when it comes to dyslexic children, the dysfunction or failure of the left hemisphere affects the information processing speed, which makes it difficult for the child to be able to process rapid changes of successive stimuli, both in the auditive and in the visual area.
A report written by Kaufman and Galaburda in 1989 thoroughly display the evidence of anatomical and functional abnormalities in dyslexia. There, the authors prove that in the brain of the dyslexic, there are specific abnormalities of the cerebral cortex, as well as different asymmetries in the parietal, temporal and frontal lobes, and an abnormal metabolism in the right cerebellum. (Figure 12)
Since dyslexia is primarily a learning problem, the characteristic personality will stand out in the classroom either by shyness and seclusion, or by a disruptive behaviour, talking, fighting, not working, as ways to achieve the acknowledgement that he or she cannot obtain through his school performance.