I remember learning about a study in a neuroscience class regarding language and how, before the critical period in a child's mind, they could learn many languages because their brain had not settled on any one particular language. The "shape" of words (word length, voxels, parts of speech etc) effectively became hard coded in their minds after the critical period ended so they could easily recognize that language, but from then on they can't learn languages easily as precritical period.

Anyone familiar with the topic care to further elaborate on this phenomenon? thanks