A look of fear can make an impression on someone faster than a smile, psychology experts say.
A look of fear can make an impression on someone faster than a smile, psychology experts say.
Researchers at Vanderbilt University in Nashville have found the
human brain processes a fearful look faster than a neutral or happy
expression. The faster detection is part of natural human survival
instincts, the researchers said.
"There are reasons to believe that the brain has evolved mechanisms
to detect things in the environment that signal threat. One of those
signals is a look of fear," David Zald, associate professor of
psychology at Vanderbilt University in Nashville, said in a release.
"We believe that the brain can detect certain cues even before we
are aware of them so that we can direct our attention to potentially
threatening situations in our environment."
The findings, which will appear in the November edition of the
journal Emotion, were based on tests that asked subjects to look into a
microscope-like viewer, which used a technique known as continuous
flash suppression to show different images to each eye.
One eye was shown rapidly changing images, which acted as visual
"noise" that suppressed the static faces being shown to the other eye.
The subject would eventually overcome the noise shown to one eye and
mentally block it out, thus recognizing the static image of the face
displayed to the other eye.
Subjects indicated when they first became aware of seeing the faces,
which showed different emotions, enabling researchers to gauge how long
it took for the different expressions to register.
The researchers said an area of the brain called the amygdala, which
shortcuts the normal brain pathway in processing visual images, is
responsible.
The shape of the eye, particularly on fearful faces, may also play a key role in the mental processing of emotions.
"That may be the sort of simple feature that the amygdala can pick
up on, because it's only getting a fairly crude representation," Zald
said. "That fearful eye may be something that's relatively hard-wired
in there."