PBS air date: January 25, 2005
ROBERT KRULWICH: We humans are really good at reading faces and bodies. 'Cause if I
can look at you and feel what you're feeling, I can learn from you, connect to you, I can love
you. Empathy is one of our finer traits, and when it happens it happens so easily, perhaps
because…we may have some special circuitry in our brains that helps us whenever we look
at each other.
Ask yourself, "Why do people get so involved, so deeply, deeply involved, with such
anguish, such pain, such nail biting tension over football?"
ROBERT KRULWICH: Why are we such suckers for sports? And it's not just sports. We can
lose it completely at the movies, at video games, watching a dance. Is there something
about humans, humans particularly, that allows us to connect so deeply when we watch
other people—watch them moving, watch them playing, watch their faces?
Well, as it happens, scientists have an explanation for this strange ability to connect…A set
of brain cells, found on either side of the head, among all the billions of long branching cells
in our brain, these so-called "mirror neurons," have surprising power.
And it began entirely by accident, at a laboratory in the lovely old city of Parma, Italy,
where a group of brain researchers was working with monkeys, and they were testing a
neuron—that's a brain cell—that always fired...made this sound whenever the monkey
would grab for a peanut. So the lab had all these peanuts around, and whenever the
monkey made its move, the neuron would fire.
…One day, the monkey was just sitting around, not moving at all, just sitting, when a human
scientist came into the lab. And when that scientist grasped the peanut? Yeah, the monkey's
Now, the monkey hadn't moved, it was the human that had moved, suggesting that this
neuron up here couldn't tell the difference between seeing something and doing
something—seeing and doing were the same—or more intriguingly, that for this neuron,
watching somebody do something is just like doing it yourself.
GIACOMO RIZZOLATTI (University of Parma): The same neurons, one neuron, fired, both
when the monkey observed something, and when the monkey is doing something. It is
ROBERT KRULWICH: Some people call them "monkey see, monkey do" neurons, but the
name that stuck is "mirror neurons," because with them, the brain seems to mirror the
movements it sees.
This accidental discovery got scientists thinking, doing more tests, and soon it came pretty
clear that this is not just a monkey thing, it's a people thing, too.
We all know that humans learn by looking and copying; that's what infants do.
ROBERT KRULWICH: And once you've watched and copied and learned a set of moves,
you not only have them in your head, if you see somebody else doing it you can share the
experience. They know the moves, you know the moves, so you can move with them…So
that's why, when I head down the street carrying all these packages, not only do people
watch, they feel my predicament because they know what it's like to carry heavy packages.
They know all about "carrying." So as they watch me moving they can feel themselves
moving. Their neurons are "mirroring" the action.
These neurons may be the brain's way of translating what we see so we can relate to the
And that's why sports fans tense with the action, and wince, and leap. 'Cause if you know
the game...then your neurons are firing as if it's you playing, giving whole new meaning to
the phrase "armchair quarterback." That's why it's so easy to be a sports fan.
But there is more, suggests U.C.L.A. professor Marco Iacoboni. He thinks mirror neurons tie
us, not just to other people's actions, but to other people's feelings.
MARCO IACOBONI (University of California, Los Angeles): So the idea was to try to figure
out how the emotional system and this motor system are connected together.
ROBERT KRULWICH: Iacoboni says that the part of my brain that's working when I make
a face, the same part gets busy when I see the face.
…Mirror neurons, he believes, can send messages to the limbic, or emotional system in our
brains. So it's possible these neurons help us tune in to each others' feelings. That's
MARCO IACOBONI: We strongly believe that that's a unifying mechanism that allows
people to actually connect at a very simple level.
ROBERT KRULWICH: You are saying that there's a place in my brain, which...whose job it
is to live in other people's minds, live in other people's bodies?
MARCO IACOBONI: That's right.
ROBERT KRULWICH: And great actors instinctively know that if they put feeling and
drama into their bodies,...their faces, we will respond.
DANIEL GLASER: What actors are experts in is using their movements to inspire feelings in
the people watching. These are the experts in the mirror system.
ROBERT KRULWICH: So if mirror neurons help us connect emotionally, what about
people who have trouble with this? Kids like Christian, who has autism?
V.S. RAMACHANDRAN: It's been known for some time that children with autism could be
quite intelligent, but have a profound deficit in social interaction.
ROBERT KRULWICH: Christian can speak and read and write, but like many kids with
autism, he will avoid eye contact, he often misunderstands questions…They recorded
brainwaves while the kids opened and closed their hands and while they looked at a movie
of somebody else's hands. For most people, the brainwave looks the same either way,
whether they're doing or seeing. But for the kids with autism, the wave changes,
suggesting, possibly, that autism might have something to do with broken mirror neurons.