Why is it that humans can speak but chimpanzees, our closest living relatives, cannot? The human brain is uniquely wired to produce language. Untangling this wiring is a major frontier of brain research. Peer into the mental machinery behind language with this feature video, which visits a brain-scanning laboratory-Columbia University's Program for Imaging and Cognitive Sciences, or PICS. Columbia neuroscientist Joy Hirsch and New York University psychologist Gary Marcus explain what researchers have learned about how our brain tackles language-and what's left to learn.