Dyslexic brains aren’t all the same
A recent study by a Hong Kong research team has shown that developmental dyslexia affects different parts of children’s brains, depending on whether they read Chinese or English.
When a child learns to read, it is somewhat of a major change in the development of a young brain, which is not surprising, as reading isn’t really a natural skill to learn. Up until very recently, experts thought that the difference between pictographic languages (e.g. Chinese) and alphabetic languages (e.g. English) was that they used different neural pathways in the brain. The study by Tan et al (published this year in the Proceedings of the National Academy of Sciences) has discovered that not only different neural paths, but entirely different brain structures are the focus for the different styles of writing.
English is a somewhat phonemic language, in that when people learn to read it, they learn which letters correspond to which sounds, and then use these to build up words. When people learn how to read Chinese, they memorize hundreds, and then thousands, of symbols, which represent both words and sounds. Becoming a skilled reader changes the brain, and becoming a skilled reader of English seems to change entirely different parts of the brain than does becoming a skilled reader of Chinese.
The implication of the study is that not all methods of therapy will work for all sufferers of dyslexia. Suggested methods to help Chinese readers involve more memory-focussed exercises, whereas English readers are given more letter-to-sound based activities.
It also means that it is very possible for one person to be dyslexic in one language but perfectly capable in another.
It can also help to explain why it is so difficult for adults to begin learning a language that has a writing style completely different to one’s native language. If you grew up learning an alphabetic language, mapping out another alphabet probably won’t be too difficult, but getting your head around Chinese characters is a completely different story. Our brains haven’t had the practise. Knowing that our brains are still somewhat flexible, though, means that, as usual, we can be successful if we just keep on trying!