dyslexia

Why English is hard on the brain
20 Jan 96

                                A BOY who struggles to read English primary-school storybooks yet
                                has no trouble with university physics textbooks in Japanese is
                                challenging current thinking on dyslexia. The 17-year-old boy, known
                                as AS, is the first person shown to be dyslexic in one language but
                                not in another.

                                "This could have profound consequences for concepts of reading,"
                                says Taeko Wydell of Brunel University in west London, who has
                                studied AS. "If there is a specific brain area for reading and a person
                                has impairment in this area, in theory all his languages should be
                                affected." The case is also posing problems for researchers who argue
                                that dyslexia is a visual processing disorder.

                                AS has two English-speaking parents but lives in Japan. At the age of
                                six, he began attending a Japanese primary school, but it soon
                                became clear that he was lagging behind his Japanese counterparts in
                                English. When AS was 13, tests confirmed that the problem was
                                dyslexia, a congenital difficulty with reading.

                                The causes of dyslexia are poorly understood, but have been linked to
                                damage in part of the brain's left hemisphere known as the perisylvian
                                area. The condition is marked by an impaired ability to process the
                                written symbols of language, such as letters - which has led some
                                researchers to suggest that the problem lies ultimately in faulty
                                visual processing.

                                Intrigued by AS's case, Wydell and her colleague Brian Butterworth of
                                University College London looked at his reading in Japanese. Japanese
                                has two written forms. One, called kanji, consists of symbols that
                                carry meaning but have no phonetic value. The kana script contains
                                symbols that correspond to particular sounds.

                                Wydell first tested AS's ability to read 160 words written in kanji.
                                Many kanji characters have two pronunciations - one in the Chinese
                                from which the symbols were derived and the other unique to
                                Japanese - but only one is correct in a given context. Knowing how to
                                pronounce a word can be extremely difficult. Yet AS reads kanji at
                                undergraduate level and so has no problem with his visual processing
                                skills, Wydell told a neurolinguistics conference at Birkbeck College,
                                London, earlier this month. He has also passed competitive high school
                                entrance exams, which require expertise in kana.

                                In English, however, AS scored half as well as the average person of
                                his age when asked to read real words and made-up words out loud.
                                And he could read only one of 50 "difficult" words, such as "nausea"
                                and "aisle". Nevertheless, AS perceives English sounds "just like a
                                native", says Wydell.

                                Wydell argues that AS's case is difficult to reconcile with conventional
                                theories about dyslexia. "If AS has a problem with visual processing,"
                                she says, "it should show up even more in kanji." She accepts that
                                many children diagnosed as dyslexic may well have problems
                                processing visual information, but suspects that others - like AS -
                                suffer from a kind of dyslexia that occurs primarily in English. The
                                problem, she believes, lies in the brain's ability to tackle the English
                                language's complex system of mapping sounds to letters, which gives
                                rise to some eccentric spellings. By contrast, kana letters always
                                sound the same.

                                Not all researchers in the field are persuaded, however. "If AS's sight
                                vocabulary is so good in Japanese," asks Marjorie Perlman Lorch, a
                                neurolinguist at Birkbeck College, "why hasn't he adopted the same
                                strategy for irregular words in English?" She suspects that AS's
                                reading problems could stem from his position as a cultural outsider in
                                Japan. "Social identity and motivational factors can be crucial."

                                ALISON MOTLUK
                                From New Scientist magazine, vol 149 issue 2013, 20/01/1996, page
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