The functional and structural connection (blue arrow) between frontal and temporal language areas of the brain is impaired in individuals with dyslexia.BART BOETSScanning the brains of adults with dyslexia and normal readers, scientists found no differences in phonetic representations—the brain’s interpretations of human speech sounds. Rather, adults with dyslexia may have difficulty processing speech sounds because of a dysfunctional connection between frontal and temporal language areas of the brain, which impairs access to otherwise intact phonetic representations.
The findings, published today (December 5) in Science, came as quite a surprise to the research team. “The main aim of the study was to finally objectively demonstrate that the quality of phonetic representations is impaired in individuals with dyslexia,” said Katholieke Universiteit Leuven’s Bart Boets, who led the work. But that’s not at all what they found. “Even while scanning throughout the whole brain for local regions where the representations may be impaired . . . we could not find a single region with inferior phonetic representations in dyslexics as compared to typical readers,” Boets explained in an e-mail.
“This is the first paper that really went head on in trying to answer this question, surprisingly,” child and adolescent psychiatrist Fumiko Hoeft from the ...
