The Importance of Being Frightened
By Gisela Telis
ScienceNOW Daily News
16 June 2008

Why do we wrinkle our noses in disgust or widen our eyes with fear? A
new study
shows that doing so might help keep us alive.
The idea that facial expressions confer a survival advantage was first
posited,
perhaps not surprisingly, by Charles Darwin. In 1872, 13 years after
he
published On the Origin of Species, Darwin wrote a lesser-known tome,
The
Expression of the Emotions in Man and Animals. In it, he observed that
some
human expressions occur across cultures and even in some other
animals. He cited
the wide-eyed gasp of surprise as an example. Darwin speculated that
these
emotional faces might serve a biological function, such as getting a
good look
at an enemy.

Darwin's hypothesis went untested until 3 years ago, when cognitive
neuroscientist Adam Anderson, graduate student Joshua Susskind, and
their
colleagues at the University of Toronto in Canada decided to apply new
technology to the century-old idea. The researchers computer-generated
a
"classic" fear face: one with raised brows, popping eyes and flaring
nostrils.
They also mocked up a disgust face: the wrinkled nose, raised lip, and
narrowed
eyes familiar to anyone who's smelled rotten eggs or stepped in
something foul.
The team then asked volunteers to mimic these faces while taking
vision and
breathing tests.

Emotional faces weren't just for looks. The team found that a fearful
visage
improves peripheral vision, speeds up eye movement, and boosts air
flow,
potentially allowing a person to more quickly sense and respond to
danger.
Squinty, scrunched-up disgusted faces had the opposite effect,
limiting vision
and decreasing air flow, ostensibly to keep out substances that might
be harmful
to the eyes or lungs.

The findings, reported online this week in Nature Neuroscience, are
"pretty
radical," says Anderson, because most research on expressions has
focused on
their function in communication, not their physiological or
evolutionary
underpinnings. "No one's ever shown this in a scientific way," adds
neuroscientist Elizabeth Phelps of New York University in New York
City. "The
best kind of study seems obvious on the one hand, but no one's
demonstrated it
before," says Kevin Ochsner, a cognitive neuroscientist at Columbia
University.
"This is one of those studies."

Source: Science
http://sciencenow.sciencemag.org/cgi/content/full/2008/616/2?etoc