MIRROR NEURONS

A recently discovered system in the brain may help explain why we humans can get so worked up watching other people. 

Why do sports fans feel so emotionally invested in the game, reacting almost as if they were part of the game themselves? According to provocative discoveries in brain imaging, inside our heads we constantly "act out" and imitate whatever activity we're observing. As this video reveals, our so-called "mirror neurons" help us understand the actions of others and prime us to imitate what we see.

http://www.pbs.org/wgbh/nova/teachers/body/mirror-neurons.html