The Reading Brain
Localizing brain function for expressive and receptive language
Paul Broca, a highly respected French physician discovered that the roots of reading - language and speech is from our cerebral cortex and the left side of our brain has two major areas associated with language: expressive language the Broca's area, and receptive language the Wernicke's area
Broca's area is located in the left frontal region of our brain. Known as Broca's aphasia, (aphasia means loss of speech/language) it is a loss of fluent speech while retaining the ability to understand language.
Wernicke's area is located in the left posterior region of our brain and is almost inverse of Broca's aphasia. It is a loss of understanding the language and utters gibberish but the individual speaks with ease.
How it affects reading?
According to Shaywitz (2003), reading relies on brain circuits, the neural circuitry for reading, and both discoveries opened the door to learning how the individual's brain affects reading and suffers difficulties in reading.
Alexia is an acquired reading disability. It is someone, usually an adult who had been a good reader but suddenly loses his ability to read because of a stroke or accident. It is caused by the destruction of brain tissue, a break in the circuitry, or a "power outage" that interrupts the circuit or wiring for reading. Remember the wiring was placed correctly but was disrupted because of the stroke or accident.
Dyslexia on the other hand is different. It is where the reading fails to start with. The 'wiring' inside the brain of this individual was not laid down correctly and there was a "glitch" during fetal development when the brain is still developing for language. Thus, the improper development of the language regions damaged the neural circuitry inside the brain. This "miswired" concept is the answer to parents who said that none of them including their blood relatives have dyslexia and or language problems. And for those who have a history of dyslexia or language problems, the "miswired must have happened to any of the blood relatives and the condition has been genetically passed down to succeeding generations like to their child. Because of "miswired" or missing circuit in the brain, "tens of thousands of neurons carrying the phonologic messages necessary for language do not appropriately connect to form the resonating networks that make skilled reading possible." Shaywtiz, S. 2003.
How about severe dyslexia or mild dyslexia?
By analyzing the caused of developmental reading problem explained above, mild dyslexia is caused by less or a little damage to the neural circuitry of the language system in the brain, while severe dyslexia is the cause of severe damage of the neural circuitry inside the brain, or I would say, there are many circuits that have been miswired or missing during the developmental stage of language regions in fetal life.
Is there a cure or possible way to correct dyslexia? Not at the moment, maybe someday. Although there is no cure for dyslexia, there is a treatment for dyslexics to learn how to read, write, spell and comprehend
Why do some students can't learn how to read and spell as others do?
Why do some smart students have trouble reading and cannot comprehend what they read
How to help struggling readers acquire reading, spelling, and comprehension skills?
to be continued...