Babies and children are geniuses until they turn seven, and then there's a systematic decline. After puberty, we fall off the map. No scientists dispute this curve, but laboratories all over the world are trying to figure out why it works this way. Work in my lab is focused on the first critical period in development, and that is the period in which babies try to master which sounds are used in their language. We think, by studying how the sounds are learned, we'll have a model for the rest of language, and perhaps for critical periods that may exist in childhood for social, emotional and cognitive development. So we've been studying the babies using a technique that we're using all over the world and the sounds of all languages. The baby sits on a parent's lap, and we train them to turn their heads when a sound changes, like from "ah" to "ee". If they do so at the appropriate time, the black box lights up and a panda bear pounds a drum. A six-monther adores the task.