New analysis of infants lends further credence to the rapidly advancing theory of mirror neurons. Key to learning, mirror neurons fire in our brains when we perform physical actions but also fire similarly when we observe other people conducting those same actions. Psychologist Claes von Hofsten of Uppsala University in Sweden has shown that these cells become active before our first birthdays, earlier than scientists had anticipated.
In a 2003 experiment adults stacking blocks shifted their gaze to the site to which they were moving a block a few hundred milliseconds before the object reached the target. They did the same when watching others perform the same task. This year von Hofsten and his colleagues monitored the eyes of infants as they watched a video of a person putting little balls into a pail. Babies learn to perform this task at around nine months of age, suggesting that older infants should be able to anticipate the videotaped action but not younger infants. Sure enough, the eyes of one-year-old babies flicked ahead to the goal as they watched, but six-month-olds gazed willy-nilly.