What are the other Names for this Condition? (Also known as/Synonyms)

• Acquired Prosopagnosia
• Developmental/Congenital Prosopagnosia
• Face Blindness

What is Prosopagnosia? (Definition/Background Information)

• Prosopagnosia is a lifelong neurological disorder that is essentially characterized by the inability to recognize or differentiate faces. It is also known as Face Blindness. The disorder can either be acquired or developmental/congenital
• Acquired Prosopagnosia can be the result of traumatic brain injury (TBI), certain neurodegenerative diseases, or a stroke. However, Developmental/Congenital Prosopagnosia is a congenital disorder that is present at birth
• A few symptoms of Prosopagnosia are avoidance of using people’s names, appearing “lost” in crowded places, inability to identify people in photographs, and rarely “introducing themselves” to others
• The main treatment for this condition is developing coping mechanisms and compensatory strategies to help the individual recognize faces. The prognosis of Prosopagnosia depends on several factors including its severity

Who gets Prosopagnosia? (Age and Sex Distribution)

• Studies have suggested that Prosopagnosia affects approximately 1.9-2.5% of the general population
• The condition occurs more frequently in males than in females
• Acquired Prosopagnosia following a brain damage is typically rare
• However, Developmental/Congenital Prosopagnosia appears to be a more common condition. Around 1 in 50 individuals have this form of Prosopagnosia

What are the Risk Factors for Prosopagnosia? (Predisposing Factors)

• Individuals with a family history of Prosopagnosia have an increased risk for the condition
• Other risk factors include traumatic brain injury (TBI), stroke, and certain neurodegenerative disorders

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Prosopagnosia? (Etiology)

Prosopagnosia is considered to be a result of various abnormalities, damages, or impairments caused in the right fusiform gyrus of the brain. The fusiform gyrus is a fold in the brain that has the ability to control facial perception and memory.

• Acquired Prosopagnosia incidentally occurs after a traumatic brain injury (TBI), stroke, or neurodegenerative disorder
• Developmental Prosopagnosia is evident at birth, suggesting a genetic component. Individuals with this condition may not realise that they are unable to recognize faces as well as others
• Prosopagnosia is sometimes associated with other developmental disorders such as autism spectrum disorder, Turner syndrome, and Williams syndrome

What are the Signs and Symptoms of Prosopagnosia?

The signs and symptoms of Prosopagnosia may include:

• Failure to recognise family members or close friends, especially when one is not expecting to see/meet them
• Individuals with the condition try to remember specific features, such as voice, body shape, or hairstyle, while being introduced to or meeting new people
• Inability to watch movies or TV shows without confusing characters
• Failure to recognize oneself in the mirror
• Unable to recognise known friends and family members following small changes in their appearance, such as after a haircut or a hairdo

How is Prosopagnosia Diagnosed?

Prosopagnosia can be identified via a range of tests to assess facial recognition abilities within the following categories:

Face familiarity tests:

• Cambridge Face Memory Test (CFMT) developed by Duchaine and Nakayama is generally used to diagnose Prosopagnosia. This test has high internal reliability
  • The original version of these tests solely used Caucasian faces; however, it has been modified for more ethnicities and termed CFMT-Chinese, CMFT-Australian, including CMFT-Kids
  • Faces used for this test are anonymous; the individual would never have seen them earlier
• Benton Facial Recognition Test (BFRT) is a test used by neuropsychologists to assess the level of skill an individual has in facial recognition
  • During this test, individuals are given a target face above six faces and asked to match one of the faces to the target face
  • Images for this test solely show the face without clothing, hair, etc. to avoid the patient using compensatory strategies. However, reliability of this test is still in question
• Recognising famous faces
  • Tests used to recognise famous faces may be also used to diagnose Prosopagnosia
  • However, these tests are dependent on certain factors such as the age, education, and cultural background of the individual. Also, it would require that the individual should have seen the famous face prior to the test

Face perception tests:

• In addition to CFMT, the Glasgow Face Matching Test (GFMT) can be used to test an individual’s ability to perceive differences between faces
• It is reported that the Dartmouth Face Perception Test (DFPT) is useful for children

Neuroimaging tests:

• Many physicians choose to use functional magnetic resonance imaging (fMRI) studies to analyse whether an individual may have Prosopagnosia or not
• fMRI studies can help understand whether individuals with Prosopagnosia would show functional activation in the fusiform gyrus (the area of the brain associated with facial recognition)

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Prosopagnosia?

Apart from the symptoms mentioned earlier for Prosopagnosia, such as the inability to recognise familiar faces or even their own face, other complications may arise that include:

• Many individuals with Prosopagnosia become socially awkward, developing anxiety and/or depression
• Individuals with this condition have an inability to recognise animal faces as well
• Sometimes, individuals struggle to watch movies or TV shows, as they cannot distinguish between the different characters of the show

How is Prosopagnosia Treated?

Even though researchers are continuing to investigate the cause of the condition; currently, a formal treatment for Prosopagnosia is not available.

• Individuals with Prosopagnosia may undertake facial recognition treatments via training programs or temporary pharmaceutical intervention. However, these treatment techniques still need more investigation
• Coping mechanisms for Prosopagnosia includes remembering the way people walk, their hairstyle, voice, or even clothing
• Therapy can help treat any anxiety or depression that is related to the disorder
• Undertaking appropriate treatment for any head injury, if it is the cause of Prosopagnosia

How can Prosopagnosia be Prevented?

Currently, there are no significant methods or guidelines that can be used to prevent Acquired or Developmental Prosopagnosia.

• Researching the family history in relation to Prosopagnosia may help in understanding the risk factors for Developmental Prosopagnosia
• Genetic testing of expecting parents (including family members) will additionally help in understanding risk factors during the early stages
• Scientists are actively researching into the causal factors of Prosopagnosia and the various methods to cope with this lifelong disorder

What is the Prognosis of Prosopagnosia? (Outcomes/Resolutions)

• Individuals with Prosopagnosia have difficulty recognizing family members and even close friends. Thus, living with Prosopagnosia can severely affect an individual’s mental health as well as social standing.
• Social situations tend to be awkward for such individuals, causing them to become reserved, withdrawn, and shy
• Severe cases of Prosopagnosia can potentially lead to anxiety and/or depression

Individuals with Prosopagnosia may generally have a lower quality of life.

Additional and Relevant Useful Information for Prosopagnosia: 

The specific area of the brain that is associated with Prosopagnosia is called the fusiform gyrus.

• This area of the brain activates in response to faces. The purpose of the fusiform gyrus is to allow individuals to differentiate between faces in more detail
• The right hemisphere of the fusiform gyrus is notably more involved in facial recognition than then left hemisphere
• Acquired Prosopagnosia is related to the occipito-temporal lobe in the brain
• It is estimated that in the UK alone, around 1.5 million people may be affected by Prosopagnosia

It is interesting to note that the opposite for individuals with Prosopagnosia is termed “super-recognizers”, which is characterized by superior face recognition abilities. At Scotland Yard, London, UK, a group of specialized criminal investigators are trained to obtain these skills.