We've all had the moment when a person was just introduced to us and minutes later we have no idea what they looked like. Some people live their entire lives with the inability to recognize faces, a condition called prosopagnosia or face blindness. These people don't have vision problems, they can see the face, but somehow it all gets warped in the brain.
Researchers from Stanford University were able to alter a man's ability to recognize faces. They say the study can help solve the mystery of face blindness.
In the experiment, the researchers briefly altered a person's ability to recognize faces by sending electrical signals to two clusters of nerves present in the fusiform gyrus. The person's perception of other body parts and objects wasn't affected, but he could no longer tell the difference between faces.
The fact that the fusiform gyrus plays an important part in face recognition was discovered by Kalanit Grill-Spector and Kevin Weiner in 2010. They had discovered that the fusiform gyrus contains two nerve clusters that respond more strongly to faces than to other body parts like hands or legs, or inanimate objects like cars or buildings.
During the study, the test subject reported that the faces didn't change dramatically but just got warped.
"You just turned into somebody else. Your face metamorphosed," told a surprised Ron Blackwell, the test subject of the study, to one of the researchers.
The researcher, whose face Ron wasn't able to recognize after his brain lost the ability to distinguish between faces was Josef Parvizi, associate professor of neurology and neurological sciences at the School of Medicine.
"Ron didn't see my face vaporize or go blank. Instead, it just seemed to warp before his eyes," Parvizi said.
Ron could recognize Parvizi's face as soon as the electrical stimulation to the brain stopped, says a statement by Stanford University. When Ron was subjected to false electrical impulse ( when the button was pressed without electrical stimulation), he didn't report any inability to recognize faces, showing that electrical stimulation of two nerve clusters in fusiform gyrus can distort the ability to recognize faces.
The study is published in the Journal of Neuroscience.