March 15, 2001 -- Millions of English-speaking dyslexics might cope better with their reading disability if their mother tongue weren't so tricky, a group of scientists said today.
A new study of the brain disorder that causes difficulty in reading and writing shows that simple languages, like Italian, are easier for dyslexics to decode than English and French. That's because Italian words are spelled the way they are pronounced, unlike many words in English and French.
The study, published in the journal Science, studied adult dyslexics across three language groups — English, French and Italian.
The researchers found the same biological foundation for dyslexia across these language groups. Brain scans showed the same reduced activity in the left hemisphere of the brain in dyslexics from all three groups, according to the study.
"This research proves the existence of a universal neurological basis for dyslexia," says Uta Frith, a neuroscientist at University College London and an author of the study.
But the frequency of diagnosis of the disorder in the different countries depended on how easy it was for native speakers to spell the words in their language.
English words — like "clove" and "love," or "cough" and "bough" — that are spelled similarly, but sound different, often puzzle school children who are learning to read, because each word pair can be pronounced correctly only if it has been learned previously. For dyslexics, irregularly spelled words in French and English can be tricky throughout life.
In English, there are 1,120 ways to create some 40 sounds, whereas in Italian, only 33 combinations of letters are needed to make 25 sounds, according to the research.
In the study, Italian dyslexics did better on reading tests and made fewer errors than their English and French counterparts. Researchers say complex writing systems, such as English and French, are the problem.
The study could also explain the findings of other studies, which have shown the rate of dyslexia among 10-year-olds in the United States to be twice as high as in Italy.
"This means that in the Italian population there may be hidden cases of dyslexia," Frith says, because the relative ease of written Italian language means dyslexia may not be diagnosed as often.
"On the other hand, otherwise mild cases of dyslexia may appear far worse" in English and French, she says.
Need for Language Change?
Eraldo Paulesu, a professor at the University of Milan Bicocca who directed the study, says there is an argument for making spelling more uniform in complex languages.
"Languages with complex [writing] are difficult for both dyslexics and non-dyslexics to read," he says.