Three British men who suffered left brain damage that undermined their capacity to speak and understand language still possess a firm grasp of mathematics, a new study finds. This observation dramatically illustrates the presence of separate brain systems for language and numbers, at least in adults, say neuroscientist Rosemary A. Varley of the University of Sheffield in England and her coworkers.
The findings, however, are unlikely to resolve a long-running debate over whether children use language to develop their number sense. Some researchers argue that initial math insights arise from knowledge of the words for numbers or of grammatical rules for arranging words in phrases. Other scientists suspect that, from infancy on, language and math follow different mental and neural paths.
"I believe that dedicated brain mechanisms exist [from the start] for language and mathematics, but others on my team disagree with me," Varley says.