What is Dyslexia?Dyslexia is a read learning disorder despite the existence of the normal intelligence, good vision and hearing, systematic training, proper motivation and other psychological and social conditions.
Dyslexia is, however, much more than the inability to read. It also includes the interference of sensory information processing: visual processing, phonological coding and language understanding, or disability in all modes of perception that includes a very fast information processing.
Causes of DyslexiaDyslexia causes are still not clearly defined. It is believed that most of them lie in the persons constitution. Factors that also contribute are environmental influences that existed from the earliest days of intrauterine development, across early childhood, until the environment in which child learns reading skills. Constitution is hereditary category inherited by genetic code in the period before and during birth. Environmental causes can be controlled if parents are aware of possibility of dyslexia.
What Actually Happens During Reading?To understand what happens to someone who has dyslexia, it is necessary to briefly explain what happens during the activity of reading and writing. These processes are extremely complex involving many interconnected systems. Thus, in reading the visual parts of the cerebral cortex participate which analyze letters and their combinations, recognizing symbols sequences, processing a specific order and understanding and storing them in working memory. Also, reading involves an analytical language processes that recognize the letters, turning the voices or linking them with the meaning, form and arrangement of words in a sentence.
Dyslexia and Brain HemispheresMany scientists are dedicated to studying the causes of Dyslexia. As a result of these studies arose the theory that dyslexia may be due to delays in the development of the left cerebral hemisphere. In fact, for some reason, in the middle of pregnancy, insufficient blood flow to the baby’s brain could occur. Because of this, the cells designed for speech that should be placed in the left brain hemisphere, can detect that such situation is not suitable for them and move in the right brain hemisphere - less appropriate location for speech and language acceptance, but still better than the left one, which, because of poor circulation, at the time of development, became inadequate. Thus the right side of the brain remains for some time and in some children permanently dominant for many activities. Children with right-hemisphere dominance have a different method of receiving, processing and storing information.
GenesThe genes are important, but not crucial for the development of dyslexia. Namely, the child may have a gene for the development of dyslexia, but that does not necessarily mean that he/she will have this disorder.
EnvironmentWays of speaking and teaching to read and write greatly influence dyslexia development. There are analytic-synthetic and global method of teaching. The second one is more suitable for dyslexic children.