Research has shown that human beings have a special ability to recognize faces. We can often tell at a glance Whether the face We are seeing is familiar – even if we can’t remember the name or where we have seen the person before.
Faces are the first thing we learn to recognize visually. Newborn babies focus best on objects 20 to 25 cm (8 to 10 inches) away, and that is more or less the distance at which a baby can see its mother’s face while nursing. Most young babies love to scrutinize faces – even simple ones drawn on paper. So, it is not surprising that, as adults, our memory of faces seems to be generally very good.
As you walk down the street, you may suddenly pick out one face that you recognize from a sea of strangers – perhaps someone who works in your building or travels on the same train as you each morning. You know nothing about them, yet you recognize their face. In some professions, people could almost be said to be experts in faces. Teachers learn up to 200 or so new faces each year and can recognize former pupils many years later. The Speaker (chair) of the British House of Commons has to be able to recognize the faces of all 650 Members of Parliament.
Testing Facial Recognition
In studies of facial memory, researchers found that volunteers could recognize 96 out of 100 of the faces shown to them two days earlier. In fact, the length of time between seeing a face and being asked to recognize it seems to have little effect on memory performance – in the tests, the interval ranged from four minutes to one week. In one study, people were 100 percent accurate in recognizing a single face after six months. However, in these early experiments, volunteers were generally shown the same pictures each time. When different images of the same face were used, recognition rates were lower but still impressive – 76 percent when either the pose or the facial expression was different and 60 percent when both aspects were changed.
Some faces seem ‘typical’ or normal to us, and others quite unusual. For example, studies in the UK showed that people rated the face of British politician David Steel as ‘very typical ‘ and that of Denis Healey, another politician, as ‘very distinctive.’ Researchers found that people often become confused by a typical face and believe they have seen it before when it has not, in fact, been shown.
People can avoid being recognized by wearing a wig or a false beard, but the best disguise is distortion. A bank robber’s stocking over the head makes recognition virtually impossible because it squashes the face. A face also becomes very hard to recognize when it is turned upside-down – it seems that the brain is so thoroughly accustomed to faces being the right way up that it finds it very difficult to process facial features in any other orientation. This is something that apparently does not happen with any other type of object, which means that you would probably recognize an upside-down picture of your car more readily than an upside-down picture of your mother.
Storing Faces
To investigate the types of brain processes that might be involved in achieving facial recognition, scientists have created computer models incorporating ‘face recognition units’, or FRUs. An FRU will respond if it finds a match to an image of a specific face, producing ‘recognition. ‘ Other recent research shows that the brain does indeed contain cells that respond to very specific images – perhaps as specific as an individual face.
When No One Looks Familiar
Prosopagnosia or ‘face blindness results from a specific brain malfunction and causes people to lose the ability to recognize faces, even those of their own family. One sufferer, an eminent professor of psychology, used to recall the time he had met an attractive woman on a theatre trip with friends. When he asked discreetly who she was, his friend explained it was the professor’s wife! The professor also had problems identifying his students and often had to rely on cues such as voice, physical shape, or clothing.
Another sufferer described in studies as PH became face blind after receiving a head injury in a motorcycle accident. In a test, he was unable to recognize any of 20 highly familiar faces. Even when presented with pairs of faces, one familiar and one unfamiliar, he was unable to tell which one was familiar. But when he was given the names to put to each pair of faces, he made a few mistakes- he clearly knew who each person was but could not access this information just from seeing the person’s face. PH could also identify that a series of different views belonged to the same face and could recognize which emotion a face was showing. Only face recognition seemed to be affected.
However, it has been found that people like PH may recognize faces at an unconscious level. When connected to a type of lie detector, they show an involuntary physical reaction whenever they see a familiar face.
Faces from the past
If we spend a period with the same group of people, their faces may become so familiar that we can still recognize them many years later. At reunions to mark the 50th anniversary of the 1940 Dunkirk evacuation, many veterans recognized comrades they had not seen since the war.
