the gyrus(es)

[Guest guest]

" Novel Brain Areas Associated With The Recognition Of Gender, Ethnicity

And The Identity Of Faces " dated 14 December 2006 in a press release from

University of Southern California <http://www.usc.edu

<http://www.usc.edu>> at

http://www.sciencedaily.com/releases/2006/12/061212091823.htm.

<http://www.sciencedaily.com/releases/2006/12/061212091823.htm.>

" Researchers in Southern California have isolated brain regions that respond

selectively to the cues of gender, ethnicity and identity in faces. Using a

novel adaptation technique, they found evidence for neurons that are

selectively tuned for gender, ethnicity and identity cues in an area not

previously thought to be associated with face processing. Led by researchers

at the University of Southern California (USC), the work is a collaboration

between USC, the Salk Institute for Biological Studies, and the University

of California at San Diego (UCSD). The findings appear Dec. 11 in the

Proceedings of the National Academy of Sciences. " When looking at a face,

its gender and ethnicity tends to be the first thing we notice, " says Ione

Fine, Ph.D., assistant professor of ophthalmology at the Keck School of

Medicine of USC and the principal investigator of the study. " We become

sensitive to these cues remarkably early in life. If you look at how

pre-school children classify faces you find that these very young children

pay attention to gender, ethnicity and age. In contrast, small children

barely notice if a person is wearing eyeglasses. We wanted to see what was

happening in the brain. " The experimenters relied on an adaptation

technique. Over a period of three minutes subjects were adapted to a series

of male Asian and female Caucasian face images. The researchers then

interposed occasional female Asian and male Caucasian face images and

measured how the appearance of these faces was altered by the previous

adaptation. They found that adaptation altered the appearance of faces-

adaptation to male Asian and female Caucasian faces made male faces appear

more Caucasian and female faces appear more Asian. The authors then used

functional magnetic resonance imaging to measure brain responses using the

same paradigm. This allowed them to isolate brain responses driven by very

selective neurons tuned for both ethnicity and gender. As expected, they

found brain responses to the female Asian and male Caucasian face images

within regions in the fusiform gyrus, a brain area previously associated

with face processing. More surprisingly, however, strong responses were also

found within the cingulate gyrus, a brain area not previously associated

with face processing. These selective brain regions also seemed to be

sensitive to the cues of identity, suggesting that they may also be involved

in recognizing individuals. " A surprising percentage of the population

-maybe 2 to 3% of the population- have a real inability to recognize faces

or even tell if someone is a male or a female, " says co-author Minna Ng, a

graduate student at UCSD. " In the most extreme cases it's a clinical

condition called prosopagnosia. Until now, most people assumed that

difficulties with face recognition were due to cortical deficits near the

fusiform gyrus. These data suggest that other brain regions may be involved.

The fact that the cingulate gyrus is involved has some interesting

implications for conditions like autism spectrum disorders. " ... "