[Ailist] How Brain's 'Mirrors' Aid Our Social Understanding - washingtonpost.com

[Hank Kearns]

Thought this might be of interest to the group.



How Brain's 'Mirrors' Aid Our Social Understanding
By Shankar Vedantam
Washington Post Staff Writer
Monday, September 25, 2006; A08

Whenever my editor approaches me, I quickly size up his body language  
before he has said a word. If he looks genial and relaxed, he  
probably liked my story. If his face looks set and determined, I know  
a wrangle over copy is probably ahead.

Human beings are exquisitely attuned to social cues and the behavior  
of others. Such signals tell us what is ahead and give us time to  
prepare. They tell us about many things that are never explicitly  
articulated in everyday life. Much of the time, in fact, we do not  
appreciate how skilled we are at reading social situations. We only  
realize how ingrained our ability to read social cues is when we see  
people with serious deficits in social awareness, such as people with  
autism or schizophrenia.

One of the most intriguing theories to emerge in recent years about  
how our brains perform these feats -- far beyond the ability of the  
most powerful supercomputers -- is that we have neurons in our brains  
that essentially act as mirrors of people around us. When we see  
someone scratch his head or furrow her brow, we instantly have a  
sense of their mental state, because those actions trigger an  
equivalent pattern of neural activity in our own minds and allow our  
brains to quickly deduce the other person's mental state.

"These mirror systems give us a fast and intuitive idea of what is  
going on," said neuroscientist Christian Keysers at the University of  
Groningen in the Netherlands. "If I hear a rhythmic squeak in the  
hotel room next door, I quite intuitively get a sense of what is  
going on in there without having to do much thinking. Much of our  
social understanding is at this level. If I see you grab a hamburger,  
I know you are hungry. There are so many things we intuitively  
understand without much thought."

This is why, Keysers added, a radio commercial can be highly  
evocative even though all you hear is the sound of a can being  
opened, a liquid being poured into a glass filled with tinkling ice  
cubes, followed by a contented "Ahh!" The mirror system allows us to  
virtually experience that soft drink as if it were in our own hands.

Three new studies published independently last week in the journal  
Current Biology have yielded new insights into "mirror neurons" and  
point the way to two intriguing conclusions: The mirror system seems  
to be involved in the human capacity for language, and people with  
stronger mirror neuron responses to sounds seem to also have a larger  
capacity for empathy, suggesting the mirror system is part of the  
brain mechanisms that produce altruistic behavior.

Keysers and his colleagues placed volunteers in fMRI scanners that  
monitor the activity of distinct regions of the brain and played  
sounds related to hand actions, such as the noise made by a piece of  
paper being torn or a zipper being opened. The experiment, led by  
Valeria Gazzola at Groningen, found that the systems of mirror  
neurons activated by the sounds were also active when the volunteers  
tore a piece of paper themselves.

"The actions of other people stop just being a sound out there in the  
world and acquire meaning because you associate them with your own  
actions," Keysers said in a telephone interview.

The experiment leads to a question that would normally seem absurd:  
If the same brain systems light up when a person performs an action  
as when she watches someone else do it, how does the person know who  
actually did it?

In a separate experiment focusing on this rather metaphysical  
question, researchers led by Simone Schuetz-Bosbach at University  
College London, found that mirror systems in the brain allowed people  
to distinguish between the actions of another person and their own.  
In fact, the mirror systems seem to be activated only in social  
contexts -- they are designed to pay attention to those around us.

"It is a very important social function," she said. "You have to  
understand other people in order to predict what they are going to do."

In a third experiment led by Lisa Aziz-Zadeh, who is now at the Brain  
and Creativity Institute at the University of Southern California,  
volunteers were placed in an fMRI scanner while watching videos of  
hand, foot and mouth movements. Researchers observed which mirror  
systems responded. Next, the volunteers read descriptions of the same  
actions, and the researchers saw that the same systems were activated.

What this implies, said Aziz-Zadeh, is that human language may depend  
in part on the activation of mirror systems in the brain.

"The word 'cup' might activate the motor plan for grasping the handle  
for a cup," said Arthur Glenberg, a cognitive psychologist at the  
University of Wisconsin at Madison, who has studied mirror neurons  
and wrote a commentary about the new experiments. "The word 'give'  
may activate the plan for stretching out the hand with the thumb  
touching the index finger and then opening the fingers."

This means that at least some aspects of language may be rooted in a  
very physical understanding of the world, the way we see and touch  
and feel things. It helps address a long-standing puzzle about  
language: How do we understand what words mean? If words are defined  
only by other words, what does the whole deck of cards rest on?

The new research suggests that language may depend at least in part  
on representations in the brain of the physical world, a much more  
concrete way to conceptualize language. When we hear words, we  
essentially act out their meanings in our own minds.

"If we empathize with other human beings because of mirror neurons  
rather than rules, I know what it is for you to be sad because I know  
what it is to be sad myself," Glenberg said. "When I see you hurt, my  
mirror neuron system is responding; it is giving me a sense of pain."

And by removing complex thinking from the ledges of abstraction and  
rooting it in the physical world, the research also helps show how  
the physical brain can produce the ephemera of thought. To Glenberg,  
it suggests that humans are far from alone in being sophisticated  
thinkers. Research has shown -- in some ways more convincingly than  
in humans -- the role of mirror neurons in other animals.

"In fact, when I started investigating these things, I became a  
vegetarian," Glenberg said. "It became clear to me as a consequence  
of these theories of embodied cognition that virtually all animals  
are thinking, and it is difficult to draw a line between those who  
are thinking and those who aren't."

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