What does it mean to be actually ‘face-blind’: prosopagnosia

When apologizing for not recognizing someone, whether they are a friend, a relative, or a past acquaintance, we often pull the excuse “sorry, I’m a bit face-blind”. We use this phrase in conversation to describe an insensitivity to facial features, hence an inability to recognize someone with ease just by looking at them. But obviously, an excuse is an excuse. You don’t run up to your English teacher asking who she is.

So, if what we call ‘face-blind’ isn’t really the case, then what is real, medical ‘blindness’ to faces like? What underlies this special, specific ‘blindness’, and what does the world look like for those who experience this?

In neurology, there is a term for this: prosopagnosia. Prosop- is a medical prefix derived from the Greek word prosopon, meaning "face" or "person". Agnosia is the inability to recognize or identify something. Together, they describe a neurological disorder characterized by an inability to recognize familiar faces, including sometimes one's own.

Melani, D. (2023, August 7). What Is Prosopagnosia? An Odd Condition That Can Steal Your Face. Cuanschutz.edu; University of Colorado Anschutz Medical Campus.

Symptoms

As made quite straightforward with the introduction, the main symptoms of prosopagnosia relate to the insensitivity to faces. More specifically, in terms of symptoms, there are two types of prosopagnosia: apperceptive and associative prosopagnosia. Those with apperceptive prosopagnosia cannot recognize other’s facial expressions and other non-verbal cues, while those with associative prosopagnosia cannot recognize people’s faces even if they are very familiar with them.

Etiology

Prosopagnosia generally has two main causes, it can be acquired or congenital (meaning that you are born with it).

Acquired

Prosopagnosia is acquired through brain lesions that may be caused by a variety of diseases.  Most cases of acquired prosopagnosia are linked to damage in the right occipito-temporal cortex (fyi, our primary visual cortex is located at the back of the occipital), often involving the fusiform gyrus and nearby regions that normally support face perception. The fusiform gyrus is a region famous for the fusiform face area it includes. As the name suggests, this region is often indicated when the brain processes face-related stimuli. Because face recognition, like most brain functions, relies on a network rather than a single center, the exact symptoms can vary depending on which nodes and connections are affected. Common medical causes include stroke, traumatic brain injury, brain tumors, infections, or neurodegenerative conditions that involve the temporal lobes.

Congenital

Congenital prosopagnosia is more commonly referred to in research as ‘developmental prosopagnosia’: the face-recognition difficulty is present from early life, without a history of brain injury or a clear structural lesion on routine scans. Many people with developmental prosopagnosia report that they have always struggled with recognizing classmates, teachers, or even close friends unless there are obvious extra clues such as voice, hairstyle, or context. Though we might try to imagine what the world would look like with prosopagnosia, what we envision is likely inaccurate since their vision isn’t simply “blurry” or that they cannot see a face, but rather the brain has trouble building a stable identity signal from facial information.

Current evidence suggests developmental prosopagnosia can involve atypical development of the brain’s face-processing network including the fusiform gyrus, as well as other connected regions. In some families, the trait appears to cluster across relatives, supporting the idea that genetic factors and differences in brain connectivity may contribute, even though the exact genes and mechanisms are still being mapped.

Location of the Fusiform Face Areas and Lateral Occipital Complexes (© 2020 Let’s Talk Science using an image by VectorMine via iStockphoto).

Impact

Because faces are such an important cue for social interaction, prosopagnosia can have an impact that goes far beyond awkward interactions. People with prosopagnosia may fail to recognize friends in a new setting, confuse two classmates who have similar haircuts, or miss familiar people in crowds. This can create a constant need for alertness in everyday social life – scanning for clothing, listening closely for voices, or waiting for someone else to say a name first.

Over time, repeated misrecognitions can alter confidence and relationships. Research describing lived experiences of developmental prosopagnosia reports feelings such as embarrassment, anxiety about social situations, and the fear of seeming rude or uncaring. Group projects, networking events, and fast-changing social environments rely heavily on face recognition. Some people therefore avoid certain settings, while others become very skilled at building alternative systems for identifying people.

Compensation strategies & Treatment

There is currently no cure that reliably restores typical face recognition in prosopagnosia, but there are ways to reduce its daily cost. Many strategies are compensatory: instead of relying on a face alone, a person intentionally uses additional cues such as voice, hairstyle, clothing style, posture, gait, or the usual context in which they meet someone. Planning can also help, for example, reviewing photos before a meeting, asking friends to wave or speak first in public places, or arranging introductions in a group setting.

Interestingly, studies on coping in developmental prosopagnosia suggest that disclosure (briefly telling others that you have difficulty recognizing faces) can reduce stress and misunderstandings, because it changes how people interpret a missed greeting. That said, whether to disclose is a personal choice and depends on the setting.

I hope this blog has been helpful in introducing prosopagnosia, medical facial blindness, to you and that when you make excuses in the future you can remember that there are people who truly cannot tell from just a face!

Bibliography

1. Duchaine, B. C., & Nakayama, K. (2006). Developmental prosopagnosia: A window to content-specific face processing. Current Opinion in Neurobiology.

2. Barton, J. J. S. (2002). Lesions of the fusiform face area impair perception of facial configuration in prosopagnosia. Neurology.

3. Barton, J. J. S. (2008). Structure and function in acquired prosopagnosia: Lessons from a series of 10 patients. British Journal of Psychology.

4. De Renzi, E., Faglioni, P., Grossi, D., & Nichelli, P. (1991). Apperceptive and associative forms of prosopagnosia. Cortex.

5. Corrow, S. L., Dalrymple, K. A., & Barton, J. J. S. (2016). Prosopagnosia: Current perspectives. Eye and Brain.

6. Adams, A., et al. (2020). Coping strategies for developmental prosopagnosia. Neuropsychological Rehabilitation.

7. DeGutis, J., Cohan, S., DeChicchis, A. R., Mercado, R. J., & Nakayama, K. (2014). Face processing improvements in prosopagnosia: Successes and failures of training. Frontiers in Human Neuroscience.

8. DeGutis, J., et al. (2023). What is the prevalence of developmental prosopagnosia? An investigation using objective and subjective measures. (open-access: PMC).