The history of dyslexia is actually longer than most people might think—nearly 150 years. To further put that into perspective, autism was only identified and treated as a learning disability 100 years ago—and the signs of autism are more prominent. The biggest challenge researchers have had to overcome over the last century and a half has been the fact that dyslexia has no outward symptoms beyond the dyslexic's inability to read, write or do arithmetic.
As early as the 1860s it has been noted that people who suffered from brain damage in such a way that restricted blood flow through the brain would have trouble reading and speaking. This condition was called aphasia and was thought to be brought on by this type of brain damage only. This conclusion was further credited after researchers found brain lesions prominent on deceased patients' brains.
In 1895 a paper was published that suggested that children suffering from "word blindness" might have suffered brain damage at birth. The consensus changed in 1917 when the book Congenital Word Blindness was published. This book was written by researcher James Hinshelwood who maintained the primary disability was in visual memory for words and letters. He identified letter reversals, and difficulties with spelling as symptoms.
Dyslexia history takes a positive turn in 1925 when Samuel T. Orton determined that there was something else going on besides brain damage. His studies indicated that a separate reason could be causing people with no obvious head trauma to struggle with reading and writing. His research was based on the proposition that people with "word blindness" had troubles associating written words into spoken language. This theory has regained a lot of credence in recent years. But he might have missed the mark by determining that the root cause of this was an issue with brain dominance.
Orton's theories were later expanded on in the 1950s when further research found that by increasing the distance between letters, reading in essence became spelling. It was noted that signs of dyslexia would then, at the very least, not be as prominent. This led to the conclusion that dyslexia might be visually based. This was yet another turning point in the history of dyslexia.
In 1979 it was again noted in postmortem autopsy that people with dyslexia had abnormalities in the center of the brain that houses speech function.
Dyslexia history remained fairly static, with possible causes being bantered back and forth until the late 1980s when MRI technology enabled researchers the ability to watch the brain as it was functioning as opposed to postmortem.
In 2008, research in the field took yet another step forward when different sub-groups of dyslexics were compared with a control of other dyslexics. This is important because it helps establishing a baseline for better determination of degrees of dyslexia.
Today, through the use of neural imaging, it has been determined that the cause of dyslexia resides in the center of the brain where speech function takes place. The root cause, or causes, has still yet to be determined. The prevailing theories involve development of the brain, genetics, and even one theory that dyslexia might be linked to learning disabilities such as ADHD.
Throughout dyslexia history , great strides have been made, but for a condition that has been studied for so long, progress is still measured in inches. Science is closer to finding the true cause of dyslexia and developing a better way to identify individuals with dyslexia than they have ever been before. In the meantime, the best detection methods are awareness, education, and the diligence of parents.
