Nov. 7, 2007 Recent findings are rapidly expanding researchers'
understanding of a new class of brain cells -- mirror neurons --
which are active both when people perform an action and when
they watch it being performed. Some scientists speculate that a
mirror system in people forms the basis for social behavior, for
our ability to imitate, acquire language, and show empathy and
understanding. It also may have played a role in the evolution
of speech. Mirror neurons were so named because, by firing both
when an animal acts and when it simply watches the same action,
they were thought to "mirror" movement, as though the observer
itself were acting. Advances in the past few years have newly
defined different types of mirror neurons in monkeys and shown
how finely tuned these subsets of mirror neurons can be. New
studies also have further characterized abnormal-as well as
normal-mirror activity in the brains of children with the social
communication disorder known as autism, suggesting new
approaches to treatmen