LIVERPOOL, ENGLAND—Researchers at the University of Liverpool have found that that the same brain activity used in speaking is used in the making of stone tools. The team reached the conclusion after using technology developed to test patients’ language function after brain damage to analyze the brain flood flow of 10 expert flint knappers while they made stone tools. The fact that stone tool making uses the same brain patterns as speaking suggests that these two abilities co-evolved. “Nobody has been able to measure brain activity in real time while making a stone tool,” says archaeologist Natalie Uomini. “This is a first for both archaeology and psychology.”