Just A Bunch Of Heads In A Crowd

Everyday we come in contact with other people and most of us are able to see and recognize who we are looking at. For example, when I walk across campus to class, I could recognize by face people from my classes. I could distinguish one classmate from another. But just imagine being in class and not being able to recognize the face of your teacher, whom you meet at least twice a week; or imagine not being able to recognize your own roommate in your dorm. Worse, can you imagine looking in the mirror and not being able to recognize your own face?
The brain disorder—prosopagnosia—that causes “facial blindness” was discovered only a few decades ago. It is a brain impairment in which the victim cannot recognize faces, both those familiar and unfamiliar [6]. People with this unique brain disorder, even if their vision is 20/20, are unable to identify or recognize any face including those of famous people, friends, family members and even their own face. It is one of several “unitary disorders,” such as object-agnosia, dyslexia, and amnesia [2]. But unlike those who suffer from these unitary disorders, those who suffer from prosopagnosia only have problem with recognizing human faces. Otherwise, they are able to identify everything else around them. The fact that prosopagnosics could see everything except individual faces appear to indicate that face-recognition is a separate or special physiological defect of the nervous system [3].
Although we still unsure of the exact causes of prosopagnosia, there is evidence suggesting that there are areas of the brain, which specifically recognize faces. Neuropsychological studies have shown certain neurons in the brain that respond to face recognition exist. Such studies have found five-types of cells in the temporal lobe region of the brain that respond to different facial views, such as full-face views or profile views [3]. Prosopagnosia has also been studied using functional MRI brain-scans and it has been determined that a certain part of the temporal lobe called the “fusiform gyrus” responds much more strongly to faces than to other objects, showing that there is a distinct part of the brain allows for face recognition [6].
Despite the uncertainty of the brain process that makes facial recognition possible, it appears that all of the causes of prosopagnosia that have been reported stem from some form of brain damage. The damage occurs in that part of the brain cortex that is used for obtaining visual cues that allow a person to recognize faces [4]. Such brain damage sometime occurs during fetal development, or after birth from, say, a head trauma, a stroke, or some degenerative disease. Those who acquire this disorder after maturity have previously had normal face recognition abilities; but after that part of the brain processing face recognition has been damaged, they acquire prosopagnosia [6].
In one case, for example, a soldier lost the ability to recognize faces as a result of taking a bullet to the head. Although he survived, he was unable to recognize individual faces because the bullet had struck that part of the brain that processes facial recognition [4]. People, like this soldier, who become afflicted with prosopagnosia after having been able to recognize faces are better at detecting their impairment more rapidly because they notice a change in their perception of individual faces. However, people who suffer from this disorder since birth may not know about their impairment, even through middle age [6].
People with prosopagnosia, however, are not all the same and lack facial recognition in different ways. Because the affliction results from damage to the cortex, a large part of the brain, each patient is affected slightly different [3]. For most individuals with the disorder, the problem sometimes is not always about detecting the face itself since they could see the eyes, noses and mouths. Rather, it is the inability to recognize the same features on an individual face, particularly when you encounter the same face again, later on [5]. For other prosopagnosics, it is difficult for them to distinguish the distinct features of a person's eyes, nose, and mouth, which makes them different from another person. Thus, to a prosopagnosic, everyone looks the same because they are unable to recognize the different features of each face, even the faces of individuals that they are very close to. One victim described how looking at several human faces was like as looking at a bunch of golden retrievers [1]; all the faces look the same--human, but he has difficulty telling the faces apart. In some cases, sufferers cannot even see actual eyes, noses, and mouths. They could only see the shape of a person's head; and the area where the face is, is just a blur or a swirl of their general facial features.
But although prosopagnosics are unable to recognize the faces of people, they are able to recognize people in other ways. One of the easiest ways for them to recognize a person is through the hair. Other ways of recognizing a person include their voice, clothing, or other unique features on their body [7].
There is no question, of course, that people who suffer from prosopagnosia do encounter many social problems, as a result. For example, they cannot tell the emotional expression of another person. A person could be sad or angry with someone with prosopagnosia, but he/she would not be able to see this, unless the person who is sad or angry with them actually speaks or acts in a way that shows their anger or sadness. A person suffering from this disorder once noted a time when her friend was sad and silently crying in front of her. Because she could not tell what was happening, she could not sympathize with her friend.
Prosopagnosics may also viewed as snobbish or unfriendly at times because they usually do not stare straight at a person’s eyes. Indeed, sometimes they appear to be ignoring you when you are talking to them because they cannot see your face when you are looking at them. Young people who suffer from this disorder thus lose friends because they appear unsympathetic or aloof [5]. They sometimes also have difficulty identifying another’s gender or age. Although hair and body shape is usually a good indicator of one's gender, in a unisex world this is sometimes difficult to distinguish by a person suffering from prosopagnosic. Most of the time, people who have prosopagnosia go to great lengths to figure out who is talking to them. Very often, they try to avoid using actual names until they are certain who the person is. Or they will try to lead the conversation in a direction that will give them an idea as to who they are speaking to. And many times, they will try to avoid a situation where they do not know who they are with [7].
Those who live with this disorder have very different lives and see the world from a very different perspective. Because they do not recognize faces, they usually do not get involved in the ordinary world that most of us encounter or engage in. Young prosopagnosics do not really care about what they look like or about the fads and fashions of the day; a trend I wish more people, including I, would care less about. Instead, prosopagnosics deal with people based usually on their personality, using their other senses rather than their visual sense. Because they do not give much thought to how others perceive their look, they appear more honest and frank in their view of things, unlike those of us who are always careful of what others might think of us.
The lives of those suffering from prosopagnosia do color their perception of how they see the world. A study has shown that about 1 in 50 people are afflicted with some form of prosopagnosia; that is 5 million people in the U.S. alone [5]. This is a very large number and raises a question about the perception on reality. If a large number of people who do have some form of this disorder exists, how do we know what we see is real? My reality consists of billions of unique faces, but for a person who was born with prosopagnosia, their reality is one that has no unique faces at all. It is amazing how a difference in brain structure can alter one's perception of the world and provide them with such different perspectives.

 

1. Bakalar, Nicholas. "Just Another Face in the Crowd, Indistinguishable Even if It's Your Own". The New York Times. 18 July 2006. <http://www.nytimes.com/2006/07/18/health/psychology/18face.html>

2. Ellis, Andrew and Young, Andrew. Human Cognitive Neuropsychology. Cambridge, UK: Psychology Press, 1996.

3. Lund, Nick. Attention and Pattern Recognition. Great Britain: TJ International Ltd., 2001.

4. Mick, Haley. "We know each other, but who are you?" Global Life: Health. 10 January 2008. <http://www.theglobeandmail.com/servlet/story/RTGAM.20080110.wlfaceblind10/BNStory/specialScienceandHealth/?page=rss&id=RTGAM.20080110.wlfaceblind10>

5. Song, Sara. "Do I Know You?" Time Magazine. 10 July 2006. <http://www.time.com/time/magazine/article/0,9171,1211572,00.html>

6. The Presidents and Fellows of Harvard College. Prosopagnosia Research Center. 2001-2007. <http://www.faceblind.org/research/>

7. "What are face-blind people like?" 26 May 2002. Welcome to my page about Prosopagnosia. <http://www.prosopagnosia.com/main/likewhat/>