The teenage brain is an unfinished product, continuing to develop in spurts until about 25. During the brain's growth spurts, the nerve endings grow rapidly, called blossoming. During that time, the cells that fire strengthen networks. The ones that don't die back, called pruning.

If a function of the brain doesn't get developed at the proper time, a person will have trouble developing that function later. For example, if 2-year-old has chronic, untreated ear infections, the child could end up with permanent hearing problems, because his auditory functioning is being wired then.

By clicking the illustrated brain, find out which parts of the brain handles which functions, and, for some, when during a person's life these areas are wired.