English is tricky. Words with the same letter combinations can have entirely different pronunciations: mint and pint, for instance, or love and clove.
But even though English-speakers have higher rates of dyslexia than those who speak Italian, a new research study shows that the learning disability is rooted in the same processing problem in the brain regardless of people’s native language.
By studying dyslexics with three different native languages, the researchers from England, France, and Italy—led by Dr. Eraldo Paulesu of the University of Milan-Bicocca in Milan, Italy—believe they have discovered why rates of dyslexia vary so much from country to country: Languages that have more complicated writing systems make the disorder’s symptoms more apparent.
The results of the research were published in the March 16 issue of the journal Science, which is published by the Washington-based American Association for the Advancement of Science. The association billed the study as the first to establish strong evidence that the learning disability has a universal anatomical and neurological basis.
Prevalence Varies
The researchers studied 72 adult dyslexics in France, Italy, and the United States. Italian-speakers did better in reading tests than speakers of English and French, which the researchers attributed to the fact that the written form of Italian is less complex than the other languages’. For, example English has 1,120 ways of representing 40 sounds, while Italian has 25 sounds represented by only 33 combinations of letters.
“In Italy, we have many students with dyslexia who have difficulties because of it, but are not diagnosed because the reading task is not too difficult,” said Dr. Paulesu, a neurologist. “In English, we need to make the language simpler.”
To help teachers in English-speaking countries reach dyslexic students, Dr. Paulesu said, he favors reforming the written language itself, or using a phonetic system to teach reading.
Blood Flow Tracked
Brain scans conducted for the study revealed that speakers of different languages had the same reduced activity in a part of the brain called the left temporal lobe while they were taking part in reading tests.
To determine if the problem was neurological, the researchers used the brain scans to track regional blood flow in the brain and neural activity while the subjects were reading.
“The study confirmed what we suspected,” said Uta Frith, one of the study’s principal researchers and the deputy director of the Institute of Cognitive Neuroscience at University College London in England.
“Reading and writing performance does not define dyslexia, since there are differences across languages, also across ages within the same language,” she continued. “To define dyslexia, a neuro-cognitive explanation is required. This is beautifully demonstrated by the cross-language results.”
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Professor Frith said the study should help educators who teach students with dyslexia.
“There should be increased understanding that satisfactory literacy learning is possible,” she said, noting that the subjects of the study were university students.
Ms. Frith said the study might also help educators shape the reading curriculum in the early grades.
“Teachers could put a potential focus on a simplified start in teaching to read in English,” she said. Further help, she added, could come from “restricting the corpus of words or syllables to those that are as regular as possible.”
Ms. Frith said she hoped to continue researching the brain functions of people with dyslexia. For example, she said, researchers “still need to find out what happens in dyslexic brains while they are doing other tasks” besides reading.
The research was sponsored by the Gatsby Foundation and the Wellcome Trust, both based in London, as well as the U.K. Medical Research Council, based in Cambridge, England.
Coverage of research is underwritten in part by a grant from the Spencer Foundation.
