Here is an interesting article about the wiring of the brain for literacy.
A lot of what we are doing during Easyread is to link the visual cortex to the auditory cortex. That is quite an unnatural pairing and so does require effort to set up. Most of the children displaying signs of dyslexia tend to link their visual cortex straight through to their Frontal Lobe when reading.
The article gives clear evidence of how necessary it is for the auditory cortex and linguistic areas of the brain to be involved in successful reading:
Guerrillas Help Locate Literacy in our Brain
Best wishes David