Prosopagnosia, also called face blindness, is a cognitive disorder of face perception in which the ability to recognize familiar faces, including one’s own face (self-recognition), is impaired, while other aspects of visual processing (e.g., object discrimination) and intellectual functioning (e.g., decision making) remain intact.

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Pathophysiology

• Fusiform gyrus
  • Specific brain area usually associated with prosopagnosia
  • Activates specifically in response to faces
• For those with prosopagnosia, the new method for recognizing faces depends on the less-sensitive object-recognition system.

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Clinical features

Types

Acquired prosopagnosia

Results from occipitotemporal lobe damage and is most often found in adults.

• Apperceptive prosopagnosia 
  • Acquired prosopagnosia with some of the earliest processes in the face perception system.
• Associative prosopagnosia
  • Acquired prosopagnosia with spared perceptual processes but impaired links between early face perception processes and the semantic information we hold about people in our memories.

Congenital prosopagnosia (CP)

Individual never adequately develops the ability to recognize faces.

• Developmental prosopagnosia (DP)
  • Face-recognition deficit that is lifelong, manifesting in early childhood, and that cannot be attributed to acquired brain damage.

Associated disorders

Other disorders that are associated with nearby brain areas:

• Left hemianopsia
  • Loss of vision from left side of space, associated with damage to the right occipital lobe
• Achromatopsia
  • Deficit in colour perception often associated with unilateral or bilateral lesions in the temporo-occipital junction
• Topographical disorientation
  • Loss of environmental familiarity and difficulties in using landmarks, associated with lesions in the posterior part of the parahippocampal gyrus and anterior part of the lingual gyrus of the right hemisphere.

Case study

• Reddit /r/IAmA
  • IAmA Person living with Prosopagnosia, which basically means I am unable to recognise faces. AMA!

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Diagnosis

Clinical diagnosis

Cambridge Face Memory Test (CFMT)

 20-item Prosopagnosia Index (PI20)

1. My face recognition ability is worse than most people
2. I have always had a bad memory for faces
3. I find it notably easier to recognize people who have distinctive facial features
4. I often mistake people I have met before for strangers
5. When I was at school I struggled to recognize my classmates
6. When people change their hairstyle, or wear hats, I have problems recognizing them
7. I sometimes have to warn new people I meet that I am ‘bad with faces’
8. I find it easy to picture individual faces in my mind
9. I am better than most people at putting a ‘name to a face’
10. Without hearing people’s voices, I struggle to recognize them
11. Anxiety about face recognition has led me to avoid certain social or professional situations
12. I have to try harder than other people to memorize faces
13. I am very confident in my ability to recognize myself in photographs
14. I sometimes find movies hard to follow because of difficulties recognizing characters
15. My friends and family think I have bad face recognition or bad face memory
16. I feel like I frequently offend people by not recognizing who they are
17. It is easy for me to recognize individuals in situations that require people to wear similar clothes (e.g. suits, uniforms and swimwear)
18. At family gatherings, I sometimes confuse individual family members
19. I find it easy to recognize celebrities in ‘before-they-were-famous’ photos, even if they have changed considerably
20. It is hard to recognize familiar people when I meet them out of context (e.g. meeting a work colleague unexpectedly while shopping

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Management

No widely accepted treatments

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Short movie