In 1944, German neurologist Joachim Bodamer described a 24-year-old patient who came to his clinic with a gunshot wound in the head that had caused damage to the areas of his brain associated with visual processing. As a result, he was completely blind for several weeks. As his sight gradually returned, he continued to have difficulties perceiving colors and forms. Bodamer noticed that the patient could see faces, but he could not assign the face to its owner. To him, all faces looked alike and he could only distinguish whether a face belonged to a man or a woman from external features, such as hair, clothes, etc. This was a case among others described by Bodamer in his 1947 report, in which he used the term "Prosopagnosia" for the first time; a combination of the two words "prosop" for "face" and "agnosia" for "ignorance".
What is prosopagnosia?
It is a neurological disorder that causes a person to not recognize or distinguish faces. This condition is not related to memory loss, vision impairment, or learning disabilities. With a prevalence of 2.5%, prosopagnosia can happen in two different ways, either as an acquired condition or as a congenital problem. Acquired prosopagnosia results from a stroke in the brain, a traumatic brain injury, Alzheimer's, dementia, or another neurodegenerative disease. Congenital prosopagnosia refers to a disorder where a child is born with it due to the inheritance of some genes or the occurrence of a genetic mutation. Sometimes, this disorder appears in people with Autism Spectrum Disorder (ASD), Asperger Syndrome (AS), or Turner Syndrome (TS); this could be the cause of the social interaction challenges they face.
The patient faces various difficulties due to this disease, such as difficulty in recognizing unfamiliar or even familiar faces, including family members, friends, and spouses, as well as their own reflection in mirrors, or distinguishing faces from objects. In most extreme cases, the afflicted cannot distinguish animals, cars, or facial expressions, or determine age or gender, or recognize people sharing similar features, such as wearing a uniform. The patient experiences severe confusion while watching movies and series, and gets lost in crowded places. Children also have a hard time making friends and getting to know their parents outdoors; they feel isolated at school.
Patients experience adverse effects, including social isolation, depression, difficulties in building personal connections and in professional life, avoiding social events and meeting new people, and refusing to greet individuals by their names.
Diagnosing prosopagnosia is difficult because there is no clear line between this condition and having a below-average ability to remember faces. There are neurological and sensory tests that ensure healthy vision, as well as other tests to rule out any mental deficiencies, and for memory and the ability to identify objects, to rule out any kind of blindness—the inability to perceive a sensory stimulus. There are also diagnostic tests, such as Computerized Tomography (CT) scans, Electroencephalogram (EEG), and Magnetic Resonance Imaging (MRI); in addition to special tests for facial recognition, such as the Benton Face Recognition Test (BFRT), in which a person is asked to match a given face to one of six presented faces that are not distinguished by anything, such as hair or hats.
To date, there is no treatment for prosopagnosia; however, if the reason for this condition is curable, whether medically or surgically, it would be a feasible solution. Other cases are trained to adapt to this disorder using different tip-offs to recognize people, such as the speaker's voice, clothes, hairstyle, perfume, height, and ornaments. Several questions remain about this disorder, as well as attempts to understand and find ways to cure it.
How Exactly Do Our Brains Recognize Faces?
Face Blindness study sheds light on typical brain function - Science Nation
References
baptisthealth.com
blogs.scientificamerican.com
healthline.com
my.clevelandclinic.org
prosopagnosiaresearch.org
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