The walnut sized brain of the African grey parrot may actually be capable of comprehending abstract mathematical concepts. The bird seems to understand a numerical concept akin to zero--an abstract notion that humans don't typically understand until they are three or four years old. Alex, the 28-year-old parrot who lives in a Brandeis University lab run by cognitive scientist Dr. Irene Pepperberg, spontaneously and correctly used the label "none" during a testing session of his counting skills to describe an absence of a numerical quantity on a tray. This discovery prompted a series of trials in which Alex consistently demonstrated the ability to identify zero quantity by saying the label "none."