wordstorage

Mind files
21 Nov 98

                                Hidden dangers of Caesarean births, body clocks and where the
                                brain stores word meanings all featured at a meeting of the
                                Society for Neuroscience in Los Angeles. Alison Motluk reports

WORDS may be encoded in areas of the brain that correspond to their
meaning, say scientists in Germany.

                                Neuroscientists have suggested half a dozen possible sites in the brain
                                where semantic processing occurs. But Friedemann PulvermÜller and
                                his colleagues at the University of Konstanz thought there may be
                                more than one region. Words referring to movement could be coded in
                                the motor cortex, while hearing-related words may be coded in the
                                auditory cortex.

                                They recruited nine volunteers whose right motor cortex had been
                                damaged by a stroke, leaving their left arm paralysed. The patients
                                were asked to quickly decide whether certain words were real or not.
                                Some words, such as "write", were associated with movement, while
                                others, such as "tiger", provoked images.

                                None of the volunteers had obvious language disorders. But with
                                action words, they made more mistakes than people with normal
                                brains. On visual words they did as well as healthy people.

                                PulvermÜller thinks the difficulties occur because action words are
                                stored in the motor cortex. He believes other brain regions that deal
                                with different stimuli-from hearing to emotions-may also deal with
                                relevant words. "All cortical areas can be relevant," he says. He
                                believes this is not surprising since we learn words by association. For
                                instance, we often remember words after seeing, hearing or doing
                                what the words describe.

                                Alison Motluk
                                From New Scientist magazine, vol 160 issue 2161, 21/11/1998, page
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