Reading the future

日期:2019-03-07 02:02:01 作者:汪汶 阅读:

By Jon Sutton IT MAY be possible to identify newborn babies who will grow up to be dyslexic. Psychologists in Illinois have correctly predicted dyslexia in 8-year-olds on the basis of their brain waves just hours after birth. Earlier detection may make it possible to reduce or even eliminate reading problems in childhood. Dyslexia, a learning disability characterised by problems reading and writing, is thought to afflict around 5 per cent of the world’s population. Children are often diagnosed with the condition only after they have experienced serious difficulties in school. “By this time, children’s minds are not so flexible and they find it harder to master new skills,” says Dennis Molfese, a psychologist at Southern Illinois University in Carbondale. Molfese and his colleagues attached electrodes to the scalps of 186 babies around 36 hours old. While playing recorded speech and non-speech sounds, they monitored the size and speed of the newborns’ brainwave responses. Then they gave the children IQ and comprehension tests every two years until the age of 8, when normal, poor and dyslexic readers were identified. Comparing the newborn brain wave patterns of the three groups, the researchers spotted several telltale differences between the dyslexics and the better readers. Such differences may arise from selective damage to nerves in the fetal brain, which is thought to cause dyslexia (New Scientist, 24 April 1999, p 26). As Molfese will tell a symposium on dyslexia in October at the Max Planck Institute in Nijmegen, the Netherlands, 22 out of the 24 dyslexics could have been identified at birth on the basis of these differences, and could have received early educational intervention. However, several babies who grew up to be normal readers would also have been targeted for intervention. For comparison, Molfese chose 24 children from the normal reading group who matched the dyslexics in IQ and other skills. At birth, five of these had brain wave patterns similar to those of the dyslexic children. Rod Nicolson, an expert on dyslexic children at the University of Sheffield, is concerned that such mistakes would cause unnecessary worry for children and parents. Nevertheless, he believes Molfese is on the right track. He says a study in which the children are grouped at birth on the basis of their brain waves, rather than later after reading problems develop, would be a better measure of the technique’s usefulness. “What is needed now is a prospective study of the same brain patterns in other samples, to see if they are reliable,” he says. Such a study is already under way, says Molfese. Even if the brain wave technique proves reliable, the question of how potential dyslexics should be treated remains controversial. Molfese says infants who test positive could wear a special hearing aid that accentuates the differences between speech sounds. Some research has suggested that dyslexia arises in part from hearing problems early on. But Nicolson disagrees. He says interfering with normal hearing could slow down the rate at which children acquire language. In his view,