Prosopagnosia is a neurological disorder in which a person is unable to recognize faces. This condition is commonly known as face blindness or facial agnosia. The term prosopagnosia is derived from two Greek words, namely ‘prosop’ (meaning face) and ‘agnosi’ (meaning lack of knowledge). In severe cases, the person has difficulty recognizing familiar faces; whereas if the degree of impairment is moderate, the person is unable to distinguish between unknown faces. In very severe conditions; the person will not be able to even recognize his own face. He may even perceive faces to be objects.
People with face blindness tend to be shy and therefore withdraw themselves from a crowd. They are likely to remain socially inactive. Many of them even avoid going to the theater for watching movies as they are unable to perceive faces. This disorder is often seen in children with autism and Asperger’s syndrome. In many cases, prosopagnosia is acquired through genetic mutation. There is definite evidence to suggest that this disorder could be hereditary and can hence run in families.
Developmental prosopagnosia occurs as a result of an abnormality, injury, or impairment in the right side of the brain. Damage to the fusiform gyrus (a fold of the brain) disturbs the coordination of this part with the rest of the nervous system, thereby affecting the brain’s ability to perceive faces and store them in memory for recognition in the future. Some of the common conditions that can lead to improper functioning of the fusiform gyrus are prenatal injury, head trauma, stroke, and neurodegenerative diseases.
This disorder is diagnosed by the prosopagnosia test. In this test, large numbers of images are displayed randomly in front of the affected person. The disorder is confirmed when a person taking the test fails to realize the repetitions of human pictures in particular. Currently, there is no known treatment available for prosopagnosia. Learning to recognize voices or remembering unique physical attributes for different people can only aid prosopagnosics to recognize people and improve the quality of their life.