Scientists unlock secrets of brain

Yale researchers probe mental activity taking place as two people engage in conversation

To the untrained eye, the graph looked like a volatile day on Wall Street, with jagged peaks and valleys, but it was not describing economics. It was a glimpse into the brains of Shaul Yahil and Shaw Bronner, two researchers at a Yale University lab, as they had a chat.

"This is a fork," Yahil said, describing the image on his computer. "A fork is something you use to stab food while you're eating it. Common piece of cutlery in the West."