English Speakers: Slow on the Uptake

23 December 1999 7:00 pm

English is a peculiar language. Words such as "cough," "tough," "dough," and "bough" look like they ought to rhyme, but each one is pronounced differently. Italian, by contrast, translates letters into sounds according to a handful of simple pronunciation rules, with few exceptions. Now researchers have found some neurological consequences of these two phonetic approaches: English speakers and Italian speakers rely, to varying extents, on different chunks of their brains when they read.

For any written language, speakers look at letters or letter combinations and convert them into sounds. They then string together the sounds to pronounce a full word, at least for words that obediently follow the rules. Some words don't toe the phonetic line, however. These you must recognize before articulating.

A team led by cognitive neuroscientist Ute Frith of University College London studied both the time and the brainpower expended on reading English and Italian words. They first clocked how long it took for Italian speakers and English speakers to start to utter words or nonword strings of letters after seeing them on a computer screen. Even though the English words used in the experiment, such as "rabbit" and "basket," are common and follow standard pronunciation rules, English speakers were slower--by a few milliseconds--than Italian speakers reading similarly simple words in their native language, the researchers report in the January Nature Neuroscience.

The team next turned its attention to the brain. A different batch of Italian and English speakers looked at words or nonwords--without uttering them--while undergoing a Positron Emission Tomography (PET) scan, which measures blood flow--a proxy for activity--in the brain. The left hemisphere language areas lit up for all participants, but the signals differed slightly according to language. Italian speakers showed more activation in a brain region previously tied to processing sounds. English speakers, in comparison, preferentially activated two brain regions responsible for remembering words, such as when you have to name an object or a color.

The findings suggest that "the language system can be flexibly developed," says psychologist Julie Fiez of the University of Pittsburgh in Pennsylvania. Even though English speakers and Italian speakers get the same job done--they both turn letters into spoken words--they rely on different strategies. And even when English speakers might get away with using simple phonological rules, their years of reading an anarchic language have trained them to look up words in their mental dictionaries.

Posted In: