Signs and Symptoms
Dyslexia symptoms can be difficult to recognize before your child enters school, but some early clues may indicate a problem. Once your child reaches school age, your child's teacher may be first to notice a problem. The condition often becomes apparent as a child begins learning to read.
Before school Signs and symptoms that a young child may be at risk of dyslexia include: Late talking Learning new words slowlyDifficulty rhyming School age Once your child is in school, dyslexia signs and symptoms may become more apparent, including: Reading at a level well below the expected level for the age of your child Problems processing and understanding what he or she hears Difficulty comprehending rapid instructions Trouble following more than one command at a time Problems remembering the sequence of things Difficulty seeing (and occasionally hearing) similarities and differences in letters and words An inability to sound out the pronunciation of an unfamiliar word Seeing letters or words in reverse ("b" for "d" or "saw" for "was," for example) — this is common in young children, but may be more pronounced in children with dyslexia Difficulty spelling Trouble learning a foreign language Teens and adults Dyslexia symptoms in teens and adults are similar to those in children. Though early intervention is beneficial for dyslexia treatment, it's never too late to seek help for dyslexia. Some common dyslexia symptoms in teens and adults include: Difficulty reading Trouble understanding jokes or idioms Reading aloud Difficulty with time management Difficulty summarizing a story Difficulty learning a foreign language Difficulty memorizing Dyslexia is characterized by a delay in the age at which a child begins to read. Most children are ready to learn reading by kindergarten or first grade, but children with dyslexia often can't grasp the basics of reading by that time. Talk with your doctor if your child's reading level is below what's expected for his or her age or if you notice other signs or symptoms of dyslexia. When dyslexia goes undiagnosed and untreated, childhood reading difficulties continue into adulthood. CAUSES There are several theories about the causes of dyslexia, but all tend to agree it is a genetic condition passed on through families. It is estimated that if you have dyslexia, there is 40%-60% likelihood your child will also develop the condition. If one identical twin is born with the condition, it is very likely the other twin will also have it. Certain genes that may contribute to dyslexia have been indentified, but researchers are still unsure exactly how these genes may affect development of the brain. Phonological processing The most widely supported theory of how dyslexia affects reading and writing is known as the phonological processing impairment theory. In order to better understand this theory, it is useful to distinguish between how spoken language and written language is understood. The ability to understand spoken language seems to be a natural capacity of the human brain. This is why children as young as three years old can often speak and understand relatively complicated sentences. As a result of this natural ability, when we listen to spoken language, we do not register that a word is made up of phonemes (the smallest units of sound that make up words). We only hear the word itself. For example, when you hear the word "crocodile", you hear it as a seamless whole. You do not have to break up the word into its phonemes and then reassemble them to make sense of it (which in this case, would be the sounds "crok", "er", "dyle"). The same is not true of reading and writing. Both of these skills require the ability to first recognise the letters in a word, then use the letters to identify the phonemes, and assembling them to make sense of the word. This ability is known as phonological processing. It is thought that people with dyslexia find phonological processing much more difficult than other people. Dyslexia and the brain The reason people with dyslexia have problems with phonological processing may be because some areas of their brain function in a different way from in people without the condition. One body of research looked at three areas that are found in the left hemisphere (half) of the brain. These are known as: Broca’s area: thought to be involved in producing written words parietotemporal region: thought to be involved in analysing written words occipitotemporal region: thought to be involved in identifying written words Research has shown activity levels in all three regions of the brain as being much lower in people with dyslexia when they are trying to read. Another body of research has looked at an area of the brain called the cerebellum, which is located at the lower back of the brain. It is thought the cerebellum plays an important role in helping to process language. The cerebellum is also responsible for coordination, and your ability to estimate how much time has passed. This may explain why many people with dyslexia have problems with coordination and time management. It should be emphasised that all areas of the brain discussed above are thought to have a high degree of "plasticity". Plasticity is a term that means an area of the brain and its function is not "set in stone", but can be remodelled over time. It may therefore be possible for people with dyslexia to use appropriate treatment to effectively "rewire" areas of their brain over time and improve their phonological processing ability.
