A 3-month-old baby can't help you with your taxes, but nonetheless possesses a brain-based grasp of numbers, a new study indicates.
Previous studies suggested that, by 4-1/2 months, infants detect changes in the number of items in a set. Some researchers regard this feat as evidence for an early number sense. Others attribute it to babies' tendency to notice novel events or to other nonnumerical cues. The new study is the first to connect infant number sense with brain activity.