Written By Jasmine Kaur
Overview
Prosopagnosia is a neurological disorder characterised by the inability to recognise human faces. It is also referred to as face blindness or facial agnosia. The term prosopagnosia comes from the Greek words for “face” and “lack of knowledge.” It falls under a family of conditions, agnosias, which interfere with how your brain processes information from your senses. Face blindness can happen in two different ways, either as an acquired condition (meaning a person develops it because of damage to part of their brain) or as a congenital problem (which means a person is born with it). Although previously thought to be relatively rare, recent research suggests that around 2% of the general public may have some level of prosopagnosia. Some degree of prosopagnosia is often present in children with autism and Asperger’s syndrome and may be the cause of their impaired social development.
Symptoms
There are two forms of prosopagnosia, and the symptoms depend on the form. The two forms are apperceptive and associative. Apperceptive prosopagnosia is defined as the inability to even perceive and cognitively process the face. The patient is unable to recognize a person’s facial expressions or other non-verbal cues. Associative prosopagnosia is defined as the inability to recognize or apply any meaning to the face, despite perceiving it. This form is when the patient is unable to recognize a person’s face despite familiarity. The patient may still be able to recognise people by other means like their voice or the sound of how they walk.
Causes
The neurological basis for prosopagnosia is not particularly well understood. One theory is that prosopagnosia is the result of abnormalities, damage, or impairment in the right fusiform gyrus—the part of the brain that coordinates neural systems controlling facial perception and memory. For congenital cases, the cause could be genetic in nature. Several DNA mutations have been identified that are more common in people with congenital prosopagnosia. It was first suspected this condition had a genetic connection because it tends to run in families. But some of the mutations aren’t inherited. Such “de novo” mutations, meaning new, spontaneous mutations that neither parent had, also seem to happen more often in people with congenital prosopagnosia.
Diagnosis
There are several neuropsychological assessments used to diagnose prosopagnosia. The Famous Faces Test is a commonly used test where individuals are asked to recognise the faces of famous persons. Benton Facial Recognition Test (BFRT) assesses face recognition skills by presenting a target face above six test faces and asking individuals to identify which test face matches the target face. Cambridge Face Memory Test (CFMT) presents individuals with images of target faces and distracters to assess face recognition abilities. 20-item Prosopagnosia Index (PI20) is a self-report questionnaire that can be used alongside computer-based face recognition tests to help identify individuals with prosopagnosia.
Treatment and Prognosis
There are no cures or treatments for prosopagnosia. However, some of the causes of acquired prosopagnosia are curable. Resolving those problems might help with this condition. While recoveries are rare, individuals with prosopagnosia can learn to recognize people using cues such as hair, voice, and clothing. Treatments tend to focus on either the underlying cause of the condition or on helping the patient learn to adapt to and live with the condition. The former approach may involve medications or surgery, whereas the latter approach may involve perceptual training and coping strategies.
Prosopagnosia can be socially crippling. Individuals with the condition often have difficulty recognizing family members and close friends. It can be a source of major anxiety for people who experience it. Many experience shame, anxiety or embarrassment because they struggle to recognize people in social situations. Therapy and rehabilitation can also help you learn ways to compensate for this condition, limiting its impact on your life.
References
Mary Kugler, R. N. (2006, June 14). Prosopagnosia Causes and Treatment. Verywell Health. https://www.verywellhealth.com/prosopagnosia-2860990
Prosopagnosia. (n.d.). Brainfacts.org. Retrieved March 21, 2024, from https://www.brainfacts.org/diseases-and-disorders/neurological-disorders-az/diseases-a-to-z-from-ninds/prosopagnosia
Prosopagnosia (face blindness). (n.d.). Cleveland Clinic. Retrieved March 21, 2024, from https://my.clevelandclinic.org/health/diseases/23412-prosopagnosia-face-blindness
Seema Sundaram MD, F. (2022, October 10). Prosopagnosia - EyeWiki. EyeWiki. https://eyewiki.aao.org/Prosopagnosia
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