FRIDAY, July 14, 2006 (HealthDay News) -- Face blindness -- an inability to recognize faces -- is a common hereditary disorder that runs in families, German researchers conclude.
The study also found that face blindness, or "prosopagnosia," is one of the most frequent disorders apparently controlled by a defect in a single gene. It can also be caused by brain injury.
People with face blindness are unable to tell the difference between different faces, except for the faces of those people who are most familiar to them, such as family members.
For this study, researchers at the University of Muenster screened 689 young people from local secondary schools and a medical school. They identified 17 people with hereditary prosopagnosia (HPA), and 14 of them agreed to further interfamilial testing. All 14 had at least one first-degree relative with HPA.
The 14 participants reported that they experienced uncertainty in social situations and difficulty recalling mental images of trees, leaves, or birds. They often have difficulty following movies or TV programs because they're unable to distinguish between similar-looking actors.
While people with HPA often have difficulty recognizing faces, they're generally able to identify other facial information, such as gender, age, and emotional expression. The researchers said this suggests that these characteristics and face recognition are processed independently of one another in the brain.
The authors also noted that HPA is one of the few cognitive functions or dysfunctions that has only one symptom and is inherited.
"Neurophysical studies of people with this highly selective dysfunction might fundamentally improve our understanding of face recognition," the author wrote.
The findings are published online in the American Journal of Medical Genetics Part A.
More information
The U.S. National Institute of Neurological Disorders and Stroke has more about prosopagnosia.
