[EDLING:1677] Numbers on the Brain

[Francis M. Hult]

ScienceNOW Daily News

26 June 2006

http://sciencenow.sciencemag.org/cgi/content/full/2006/626/4

Numbers on the Brain

By Constance Holden

Brain scans have shown that speakers of English and Chinese process language 
somewhat differently. Now a new study has extended this finding, showing that 
English and Chinese speakers also process numbers differently--even though 
they use the same Arabic symbols. The authors believe it is not just language 
but mode of language learning that makes the difference.
When reading, Chinese speakers tend to rely on visual-spatial brain areas, 
while English speakers rely more on language-related brain areas. To see 
whether the same applied to number processing, a U.S.-Chinese research team 
led by Yiyuan Tang of Dalian University of Technology in China compared 12 
native English speakers living in Dalian with 12 local university students. 
The subjects, all in their 20s, were equally divided by sex, and their brains 
were scanned while they performed simple tasks. One involved looking at three 
meaningless symbols and judging the spatial orientation of the third in 
relation to the first two. This task, which activated both visual and language 
pathways, elicited no differences between the two language groups.

But when this task was repeated with numbers rather than symbols, "remarkable 
differences" emerged, the authors report online this week in Proceedings of 
the National Academy of Sciences. There was more activation in the language 
areas for the English speakers, and much more in the visual-spatial areas for 
the Chinese speakers. The differences were more pronounced in two other tasks 
that required arithmetic and comparing numerical values.

The authors speculate that it's not only language that shapes the different 
approach to numbers but also the methods used to learn language. For example, 
children rely heavily on visual copying to learn Chinese, but English speakers 
rely more on sounds. The Chinese use of abacuses also makes arithmetic more 
visual, the authors note.

The study contributes to the "surprising conclusion that culture ... shapes 
brain-behavior relations," says Charles Perfetti of the University of 
Pittsburgh in Pennsylvania, who has found that American students to some 
extent recruit "Chinese" brain areas when they study Chinese.

And cognitive scientist Michael Posner of the University of Oregon thinks the 
study could contain a message relevant to the teaching of math. Could a 
different strategy for processing numbers help explain why Chinese students 
seem to do better at math than English-speaking students do? "It could very 
well be," he says.