Dyslexia may be distinct brain disorders in English and Chinese speaking cultures, according to researchers who found different neurological deficits between the two.

The difference may stem from the fact that English uses a letter alphabet while Chinese languages use characters, the researchers write online today in the Proceedings of the National Academy of Sciences.

The researchers found that English speakers with the reading disability typically have functional abnormalities in posterior parts of the brain associated with reading and possibly also less grey matter in these areas.

But in Chinese speakers with dyslexia, the functional and structural brain abnormalities related to reading correspond with the left middle frontal region of the brain.

"The different brain networks accommodate the different features of English and Chinese. The two systems are dramatically different. Chinese is pictographic and English is more phonological, or sound-based."