Dyslexia is a common disorder that affects around 15 percent of Americans. It is a disorder that presents itself in childhood and continues throughout a person’s life. Dyslexia has no relationship to cognitive ability, as people with both low and high cognitive functioning have been reported to have dyslexia. But because people with dyslexia have great difficulty reading, spelling, and determining the meanings of words, they can sometimes be labeled as cognitively deficient.
The causes of dyslexia seem to be rooted in the wiring of the left hemisphere of the brain. The left hemisphere by and large controls linguistic abilities. For example, the left hemisphere allows us to match a letter with it’s sound, understand grammar and syntax, and other phonemic and phonetic tasks. People with dyslexia have difficulties with this because their left hemispheres are wired differently. Brain scans show that the left hemisphere is less active when a dyslexic person is performing linguistic tasks than it is in the brain of a non-dyslexic person performing the same tasks.
So what does this mean? Dyslexia is basically an information processing issue. But because a dyslexic person’s brain is wired differently, their brains have to compensate somehow. This usually means that the right side of the brain or a part of the brain called Broca’s Area has to take over some of the language processing responsibilities for the left hemisphere.
The problem with this is that the right hemisphere isn’t wired for language processing. The right hemisphere is an expert in spatial reasoning and patterns. It wasn’t intended to keep track of parts of speech or understand how to spell, which is why so many people with dyslexia have trouble with those tasks. Similarly, Broca’s Area, although responsible for language production and comprehension, was never intended to be in charge of separating a word into its individual sounds or understanding how to spell. As such, its capacity to make up for deficits in the activity of the left hemisphere is somewhat limited.
Some studies also point to problems with the corpus callosum, a bundle of nerves that connects the left and right hemispheres, as one of the potential causes of dyslexia. The corpus callosum transfers information from one hemisphere to the next, but it also decides to which hemisphere incoming information is sent. In some people with dyslexia, the corpus callosum simply sends language tasks to the right hemisphere instead of to the left. As well, the information is sent slowly, causing it to be out of sync.
By assigning other parts of the brain to take over for the left hemisphere, the brain is demonstrating its ability to adapt in order to function, a process called neuroplasticity. The new neural pathways the brain creates are intended to replace those that aren’t functioning properly. Undergoing treatments that help the brain to expand this process is an excellent method to overcome the causes of dyslexia. For more information about dyslexia and treatments for dyslexia, visit https://learningbreakthrough.com/specific-challenges/dyslexia-reading-challenges.