A STUDY recently published in the online edition of Proceedings of the National Academy of Sciences of the United States of America, one of the world’s most-cited multidisciplinary scientific journals, showed that the cause of children’s dyslexia depends on what language they are attempting to learn, AP has reported.
The study, which compared dyslexic children who are readers of Chinese with those of English, drew the conclusion that the areas of the brain affected by dyslexia differ between the two groups. English speakers who have the reading disability typically have functional abnormalities in posterior parts of the brain that are associated with reading. In Chinese dyslexics, on the other hand, the functional and structural brain abnormalities related to reading correspond with the left middle frontal region of the brain. The findings shed light on the neurological basis of dyslexia, which may help therapists seek different methods of assisting dyslexic children from different cultures.
The US-based International Dyslexia Association says dyslexia, a language-based learning disability caused by the brain’s inability to recognize and process symbols, affects 5 to 17 percent of school children throughout the world. They may have trouble rhyming and separating the sounds in spoken words. In English, this results in word distortions or transpositions of letters. In Chinese, the problem can affect how a person converts a symbol into both sound and meaning.
Past studies have suggested that the brain may use different networks of neurons in different languages, but none has suggested a difference in the structural parts of the brain involved. The findings make sense based on the vastly different nature of the Chinese and English written languages, says professor Robert Desimone of the Massachusetts Institute of Technology (MIT). Whereas Chinese relies on complex images to represent entire words, English is an alphabetic language that relies more on rules and less on pattern recognition and memory. Now these differences in the actual anatomy of the brain have been revealed, scientists are “a step closer to understanding the underlying problem” of dyslexia, adds MIT cognitive psychologist John Gabrieli.
