Dyslexia is a neuro-developmental disorder whose characteristics include complications in learning to read in spite of having enough intelligence, no emotional disorders, conventional instruction, and a sociocultural background that is balanced (Zadina, 198). Dyslexia is the common type of learning disorder.
Underlying Functional Neuroanatomy in Dyslexia
Individuals with dyslexia have four different neuro-anatomical structures. First, they do not have asymmetry of the planum temporale unlike their counterparts without dyslexia. In the Sylvian fissure part of the brain, the planum temporale which deals with language and speech is located. The lack of asymmetry of the planum temporale is caused by the difference in size of the parietal lobes and temporal on the left and the right because of the reciprocal growth of the posterior horizontal and ascending branches of the Sylvian fissure. Research indicates that since reading is a task related to language, the anatomical variations in one of the language areas of the brain is consistent with the functional limitations of dyslexia (Wajuihian & Naidoo, 27). The second functional neuroanatomy in dyslexia is the rampant distribution of neural elements which are misplaced all over the cerebral cortex, especially in the perisylvian language areas, this leads to changes in the organization of the brain. The misplaced neural elements in the brain are caused by the failure of neurons to reach their frequent targets during the development of the fetus. Thirdly, persons with dyslexia have a slow development of their nerve fibers of the corpus collosum, which is suspected to result from to the neurological etiology of dyslexia. The neurological etiology of dyslexia leads to the delaying of the development of corpus collosum thus causing an insufficient growth of language functions. Lastly, the dyslexics show a lateral spread of language functions to the left hemisphere, which is caused by its less specialization; therefore, this may cause the mixture of different speech styles since the normal growth of the language area in the brain is affected (Wajuihian & Naidoo, 27).
The Deficits Expected and the Functions that Remain Intact
Dyslexic children exhibit the following signs and symptoms during reading: skipping and reversing of words, re-reading lines, substitution of words, diplopia, inability to differentiate between letters which seems similar both in size and shape, such as e and o, and inability to differentiate between letters having similar shape but different orientation, such as p and b. Difficulties in spelling include omitting the ending or beginning a letter, and difficulties in the numeric association, etc. Reading difficulties include problems in learning to read, complications in composing or identifying rhyming words, and problems in manipulating sound in words. Verbal signs include problems in the acquisition of vocabulary, difficulties in following directions, difficulties in retrieving words, difficulties in grasping concepts and the relationships between sentences and words. Nonlinguistic difficulties include problems with early sensory processing, dyspraxia, and problems with coordination of eye movements (Wajuihian & Naidoo, 29). Additionally, children with dyslexia may experience anger, anxiety, depression, and low self-esteem.
On the other hand, the creativity aspect and the meaning of words of the dyslexic remain intact. Most people with dyslexia are very creative, and they develop some clever skills to help them figure out words and sentences that give them trouble at first. Dyslexics often have problems with the sound of words, but not their meaning.
How the Dyslexia Affects a Child Functionally at Different Levels of Development
Children undergo a process of learning how to read, which mostly a harder task for children compared to speaking (Zadina, 28). In a particular stage of development, children use the phonological model to learn. Through this, deficiency in a particular component of language system which is involved in processing the sound of words can be reflected. Also, children must be taught how to read; some children experience the difficulty of breaking a word into its smaller parts, which a crucial task in reading.
Phonemes are the smallest speech sound units which can be identified as being unique from other sounds and can be articulated in a specific language. Letters must be linked to the sound of spoken word so as to transform the printed letters on the page into meaningful words. Reading acquisition develops on the child’s spoken language. After phonologically decoding a written word, its meaning becomes available through the existing meaning of words and phrases. A significant part of this intuitive process is the automatic and accurate matching of the component speech sound with their corresponding written representations. Hence, the awareness of the sound of speech phonological structure by a child plays a key role in the growth of reading ability. For children to learn to read, it is important for them to learn how to link the printed letters on the page to the sounds of spoken language, and understand that the spoken words are composed of sounds, and that letters represent these sounds. The basic principle behind the alphabet needs to be understood so as to learn to read; this is difficult for children with dyslexia (Wajuihian & Naidoo, 31). The main reason why dyslexic children have reading difficulties is that they cannot break a word into its parts. It is crucial to note that despite phonemic awareness being critical in learning to read, it has to be supplemented by the knowledge of letters and the sounds they represent.
Interventions Used with a Child Affected by Dyslexia
The first intervention mechanism in children with dyslexia is remediation of reading, which enhances their phonologic awareness. The second intervention mechanism is accommodating the child as he/she enters secondary school, which is a more time demanding stage. The accommodation includes the provision of audio books, extra reading time, using tape recorders in the classroom, and using the spellchecker (Zadina, 98). Accommodation helps in restoring the child’s self-esteem, which is truly the most important part of undoing dyslexia. The general dyslexia intervention lies mainly in the category of psychology and education.
Wajuihian, S. O., Naidoo, K. S. (2012). “Dyslexia: An Overview.” Optometry & Vision Development, 43(1): 24-33.
Zadina, J. N. (2003). Neuroanatomy of dyslexia: A behavioral – anatomic study of dyslexia subtypes and controls.