Many don’t think much about the faces of people we know and love. Our brain rapidly identifies people as known or unknown to us without much conscious effort. Exactly how the human brain is able to recognize faces is the subject of much debate.
There is much more reason to determine exactly how the brain can identify faces than simply satisfying a medical curiosity or settling a scholarly debate. Governmental agencies are keen to develop software that can more swiftly and accurately locate wanted individuals and terrorists by picking them from a crowded airport for example by facial features alone.
The key to gaining the understanding we need to build better facial recognition technology could be to determine how the human brain is able to identify faces. Facial recognition is described by Boston.com as one of the hottest realms in psychology and neural science.
Professor of vision and computational neuroscience at MIT Pawan Sinha told Boston.com, "It's very controversial: How do we see a face?" Sinha says one of the hottest topics of debate "is whether we learn to recognize faces or whether we come prewired with dedicated brainware for recognizing faces. The disagreement is deep - and rather sharp."
There are two camps with one taking the position that we learn to recognize faces and the other asserting that the brain comes pre-wired to recognize faces. Researchers in the field have performed experiments that have offered interesting insight into how people look at faces.
Michael J. Tarr of Brown University has found that the face of males has a more reddish tone and that female faces have more green. Why the color differences in the faces of men and women? Tarr says that it could be that women need slightly different skin coloration to be able to absorb ultraviolet light for synthesizing vitamin B needed during lactation and for bone development.
Tarr adds, "The coloration is subtle, but actual - not just a trick of the mind or matter of perception. Men are redder, on average; women greener. Color information is very robust."
Other researchers from the University of California in San Diego have performed experiments that suggest the nose is a sort of main navigational focus used to help recognize a face. The researchers found during testing that people focus first on the nose, then look to the left of it and then back to the center before deciding if they recognize a face. Yet more research suggests that the eyebrows may be as important as the eyes in facial recognition. Sinha says, "Put on glasses with thick lenses or strange frames, and people will still recognize you. But shaving eyebrows is acutely disruptive to recognition."
Researcher Nancy Kanwisher from MIT believes that the human brain has a sweet spot called the fusiform face area that has developed to recognize faces. She believes that the ability to recognize faces comes as easily as breathing for people.
Other scientists researching facial recognition disagree with Kanwisher. They believe that facial recognition is an acquired skill and that clues to breakthroughs in facial recognition can be found by studying conditions that hamper recognition.
These scientists are studying stroke victims and autistic individuals, both conditions are known to make it difficult for sufferers to recognize faces. If the researchers are able to identify how humans recognize faces, it could usher in a new era in facial recognition technology.