Prosopagnosia – Lost in a sea of faces?

Screenshot 2015-04-01 21.39.39Jackie Liu discusses prosopagnosia, a cognitive disorder that leaves sufferers struggling to recognise the faces and identities of those around them.

 

Prosopagnosia is that awkward and embarrassing encounter where you are greeted by someone you supposedly know, but whose face you simply cannot recognise. It’s September in St. Andrews, you meet hundreds of new students, but a few days later in the street you have no recollection of meeting this individual because you cannot recognise their face. For some, this is a way of life, a daily threat, a constant unease. Imagine being in a crowd at a football match, lost and alone, not recognising anyone: not a single identifiable face. Prosopagnosics face this possibility everyday. This condition can lead to severe consequences.

What is prosopagnosia?

Prosopagnosia, or ‘Face Blindness’, is defined as having an inability to, or difficulty with, recognising faces: a cognitive disorder of facial perception. Some cannot perceive faces, and others cannot relate the face to an identity. This, for most people, is a simple and at least a partially unconscious process developed soon after birth, but in some this cognitive process is impaired or missing. The German psychologist Joachim Bodamer first used the term prosopagnosia in 1947 in his paper titled ‘Die Prosop-Agnosie’. It was a derivation from the classical Greek “πρόσωπον” (prósōpon), meaning ‘face’, and “αγνωσία” (agnōsía) ‘non-knowledge’ (Bodamer, 1947).

How does facial recognition work?

To understand prosopagnosia, it is necessary to understand the development of facial recognition. The process is complicated, and seems to begin in babies soon after birth. Newborn infants have been observed to show interest in, and track, basic sketched faces. This innate interest declines after the first month. This development is crucial to facial recognition as researched by Grand et al. (2001). The study examined patients deprived of normal vision with bilateral congenital cataracts, which were surgically corrected 118 days post-birth on average. This delay, however, caused an insufficient development of the facial processing ability. These patients were compared to a control group who had had no previous visual-impairment and the results indicated that deprivation of facial visual input at birth led to permanent deficits in configural facial processing – the spacing of facial features. Yet the visually deprived patients had normal featural processing – the shaping of features. So while these patients can process and recognise the shapes of features like eyes or nose, their deprivation of visual input at birth may have led to a permanent difficulty in recognising differences in the spacing of features, and hence the inability to connect identity with a specific set of facial features (Grand et al., 2001). Prosopagnosia is a defect specifically with the holistic or configurational processing of faces (Busigny et al., 2010).

Hence, prosopagnosia may lead to the dissociation of two functional processes: the recognition of a face through its’ features, and spacing. Spacing is a function that is separate from featural processing, but assists in the identification of the owner of the face, which has been discussed as a secondary process by Schiltz (2005). This paper suggests that there are indeed two levels of processing: face detection, followed by individual identification, and that these levels can be dissociated (Schiltz, 2005). In a person without prosopagnosia, these processes integrate, working largely unconsciously to enable facial recognition.

Anatomically, there is debate (Halgren et al., 2000) with regards to the location of facial recognition processes, but the general consensus is that it functionally localises to the occipitotemporal or fusiform gyrus.

Occipitotemporal or Fusiform Gyrus
Occipitotemporal or Fusiform Gyrus

Within the gyrus is an area called the ‘Fusiform Face Area’, which is suspected to function in facial recognition (Kanwisher & Yovel, 2006). Functional MRI (fMRI) reveals an increase in blood flow in the Fusiform Face Area when the patient looks at faces. The evidence shows that the Area demonstrates functional specificity in relation to faces rather than objects, and also area specificity suggested by the differences in response profiles from other face-selective regions (Kanwisher & Yovel, 2006). However, some argue (Goldstein, 2009) that the area cannot be the sole anatomical basis for facial recognition, as it is not fully developed until adolescence, and babies can differentiate faces as early as 3 months old. It also argued that cognitive functions, like facial recognition, are not limited to being domain-specific mechanisms (Kanwisher & Yovel, 2006).

Is there a difference between the two hemispheres of the brain?

Studies have suggested that the facial recognition process is expressed from the right hemisphere (Meadows, 1974). Patients with acquired prosopagnosia develop the condition after traumatic brain injury or damage. Meadows (1974) describes prosopagnosia patients as almost always having a right occipitotemporal lesion (Meadows, 1974). A study by Schiltz (2006) also provides supporting evidence for this theory, indicating a correlation between lesions in the fusiform gyrus on the right hemisphere with difficulties identifying faces (Schiltz, 2006).

 

What are the different types of prosopagnosia?

Prosopagnosia is not a unitary disorder: there are different types and levels of impairment. The condition can be categorised into two main groups: acquired and developmental. Acquired has two sub-groups:

  • Apperceptive prosopagnosia is impairment to the earliest processes in facial recognition, usually caused by damage to the right occipitotemporal region. These patients may be unable to recognise faces at all, whether familiar or not. These patients are then dependent on other factors, like voice and clothing, for recognition (Gainotti & Marra, 2011). 
  • Associative prosopagnosia is impairment to other early face recognition processes and also their links with memory, usually caused by damage to the right anterior temporal regions. These patients can determine faces and what the face may show about the person (age and sex), but cannot associate the face with anyone they know; there is no identification (Gainotti & Marra, 2011).

Developmental is defined as being present from birth, and manifests in early childhood (Jones & Tranel, 2001). Inheritance is possible: there are families with multiple members affected by prosopagnosia. It is still unknown what actually causes this condition, but it is likely to be of genetic origin.

So how can this affect people?

Acquired prosopagnosia is rare because of the location of the damage impairing facial recognition. Developmental prosopagnosia however, is relatively common. The estimated figures are between 2% to 2.9% in a general population (Duchaine & Nakayama, 2006; Kenneknecht et al., 2006; Bowles et al., 2009). This congenital form of prosopagnosia can severely affect children in many ways.

Screenshot 2015-04-01 22.02.31

There are safety issues notably created by a parent’s inability to recognise their own children or family. The condition can also create anxiety for children, especially in busy and crowded areas. Social issues are also created. A rich and adequate social life is a key part of childhood development, and prosopagnosia makes this much more difficult to maintain. Children are able to meet new people and make friends but, subsequently, fail to recognise them. This alienates prosopagnosics; they are falsely perceived as being superficial or antisocial. These children also then have difficulty in team-based activities or sports.

The condition can also create anxiety, especially in busy and crowded areas
The condition can also create anxiety, especially in busy and crowded areas

A case study describes these problems in more detail (Diaz, 2008). The paper describes the lives of a 13-year old boy and his mother, both living with hereditary prosopagnosia. Their condition limits their social interactions and circles. This was exacerbated when the boy entered middle school, where he struggled to adapt to the increased number of people. Alone and alienated, with a reputation for ‘weirdness’, he suffered from depression, and became suicidal. The school nurse then developed an individualised healthcare plan, raising awareness and understanding of prosopagnosia amongst staff, enabling them to provide educated assistance. The boy underwent psychological counselling and took medication. His mental wellbeing improved, but despite this assistance, he remained isolated, and concentrated on his studies. This case study indicates that developmental prosopagnosia can lead both to difficulty maintaining a patient’s safety, and deterioration of their mental wellbeing (Diaz, 2008). The difficulties prosopagnosia presents can affect every aspect of an individual’s life, resulting from the loss of a basic cognitive function that most people have. In an attempt to counter this, coping strategies are adopted by the patient: they rely on other characteristics for recognition, such as an individual’s gait, voice, or hairstyle. This coping strategy can achieve improvements socially, but ultimately, may be undermined by a simple haircut or even a sore throat.

Prosopagnosia is a relatively unknown condition that affects a surprising number of people. If, allowing for the 2% prevalence, then the United Kingdom alone has about 1.5million prosopagnosics. There are no known cures or standardised treatments as of yet. Patients are dependent on their own individual management and coping strategies. Even the diagnostic tests, the Cambridge Face Memory Test and Cambridge Face Perception Test – whilst being fairly reliable as clinically strong indicators – are limited by factors such as one’s age and ethnicity (there is discrimination against faces not of your own race) (Bowles et al., 2009). The inability to recognise faces reaches beyond social issues, and impacts one’s quality of life. This article aims to raise better awareness and understanding of the condition.

Bibliography

Bodamer, J. (1947) ‘Die Prosop-Agnosie’,Archiv für Psychiatrie und Nervenkrankheiten Vereinigt mit Zeitschrift für die Gesamte Neurologie und Psychiatrie. Springer, 179(1-2), pp. 6–53. doi: 10.1007/BF00352849.

Bowles, D., McKone, E., Dawel, A., Duchaine, B., Palermo, R., Schmalzl, L., Rivolta, D., Wilson, E. and Yovel, G. (2009) ‘Diagnosing prosopagnosia: Effects of ageing, sex, and participant–stimulus ethnic match on the Cambridge Face Memory Test and Cambridge Face Perception Test’,Cognitive Neuropsychology, 26(5), pp. 423–455. doi: 10.1080/02643290903343149.

Busigny, Joubert, Felician, Ceccaldi and Rossion (2010) ‘Holistic perception of the individual face is specific and necessary: evidence from an extensive case study of acquired prosopagnosia.’,Neuropsychologia. Busigny T , et al., 48(14), pp. 4057–92. doi: 10.1016/j.neuropsychologia.2010.09.017.

Diaz, A. (2008) ‘Do I Know You? A Case Study of Prosopagnosia (Face Blindness)’,The Journal of School Nursing, 24(5), pp. 284–289. doi: 10.1177/1059840508322381.

Duchaine, B. and Nakayama, K. (2006) ‘Developmental prosopagnosia: a window to content-specific face processing’,Current Opinion in Neurobiology, 16(2), pp. 166–173. doi: 10.1016/j.conb.2006.03.003.

Gainotti, G. and Marra, C. (2011) ‘Differential Contribution of Right and Left Temporo-Occipital and Anterior Temporal Lesions to Face Recognition Disorders’,Frontiers in Human Neuroscience. Frontiers Media SA, 5, p. 55. doi: 10.3389/fnhum.2011.00055.

Goldstein, B. (2009)Sensation and Perception [With Virtual Lab Manual] – 8th Edition. 8th edn. United States: Wadsworth, Cengage Learning.

Grand, R. L., Mondloch, C., Maurer, D. and Brent, H. (2001) ‘Neuroperception: Early visual experience and face processing’,Nature, 410(6831), pp. 890–890. doi: 10.1038/35073749.

Halgren, Raij, Marinkovic, Jousmäki and Hari (2000) ‘Cognitive response profile of the human fusiform face area as determined by MEG.’,Cerebral cortex (New York, N.Y. : 1991). Halgren E , et al., 10(1), pp. 69–81. Available at: http://www.ncbi.nlm.nih.gov/pubmed/10639397 (Accessed: 17 January 2015).

How does our brain know what is a face and what’s not? (no date). Anne Trafton, MIT News Office. Available at: http://newsoffice.mit.edu/2011/face-perception-0109 (Accessed: 17 January 2015).

Jones, R. and Tranel (2001) ‘Severe developmental prosopagnosia in a child with superior intellect.’,Journal of clinical and experimental neuropsychology. Jones RD and Tranel D, 23(3), pp. 265–73. Available at: http://www.ncbi.nlm.nih.gov/pubmed/11404805 (Accessed: 17 January 2015).

Kanwisher and Yovel (2006) ‘The fusiform face area: a cortical region specialized for the perception of faces’,Philosophical Transactions of the Royal Society B: Biological Sciences, 361(1476), pp. 2109–2128. doi: 10.1098/rstb.2006.1934.

Kennerknecht, I., Grueter, T., Welling, B., Wentzek, S., Horst, J., Edwards, S. and Grueter, M. (2006) ‘First report of prevalence of non-syndromic hereditary prosopagnosia (HPA)’,American Journal of Medical Genetics Part A, 140A(15), pp. 1617–1622. doi: 10.1002/ajmg.a.31343.

Meadows, J. (1974) ‘The anatomical basis of prosopagnosia’,Journal of Neurology, Neurosurgery & Psychiatry, 37(5), pp. 489–501. doi: 10.1136/jnnp.37.5.489.

Meng, Cherian, Singal and Sinha (2010) ‘Functional lateralization of face processing’, Journal of Vision, 10(7), pp. 562–562. doi: 10.1167/10.7.562.

Schiltz (2005) ‘Impaired Face Discrimination in Acquired Prosopagnosia Is Associated with Abnormal Response to Individual Faces in the Right Middle Fusiform Gyrus’,Cerebral Cortex, 16(4), pp. 574–586. doi: 10.1093/cercor/bhj005.

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