Prosopagnosia: When your brain can’t recognize faces

Kiarash Salehigilani
10 February 2015

Above: Image ©

At least once in your life, you have probably had an argument over the colour of a car, or wondered if what you consider green also looks green to everyone else. After all, what you see depends on how your brain interprets visual information and makes sense of the world around you.

Did you know? The fusiform face area (FFA) of the brain, which helps interpret faces, is also responsible for pareidolia, which refers to seeing faces in inanimate objects, like the Man in the Moon.As a result, two people looking at the same thing do not necessarily see the same thing. For example, some people suffer from a condition called prosopagnosia and cannot recognize faces as well as most people do.

Specific parts of your brain are responsible for identifying different things that you see. The fusiform face area (FFA), located in the temporal lobe on the underside of the brain, is part of a network of brain regions responsible for identifying faces. If the FFA is damaged or not working properly, the result can be prosopagnosia.

In some cases, prosopagnosia is the result of damage to brain tissue caused by stroke or injury. This is called acquired prosopagnosia. But other people never develop the capacity to recognize faces in the first place, because the regions of their brains that process faces are underdeveloped. This is called developmental prosopagnosia, and in some cases it is hereditary.

The cerebral lobes. The fusiform face area (FFA) is located in the temporal lobe. Click image to enlarge (Wikimedia Commons/US National Cancer Institute)

Prosopagnosia is fascinating because it mainly affects facial recognition and not how you see places or objects. Despite having difficulty recognizing faces, people with prosopagnosia can identify people using other characteristics, such as a their voice or the way they walk.

I happen to have a mild form of prosopagnosia, which has resulted in some awkward situations in my life. For example, when I was 5 years old, I woke up from a nap to find a person whom I thought was my mother sleeping on the bed next to me. I then walked out into the living room to find my mother there. It turned out that my aunt (who looks nothing like my mother, by the way) had come to our house while I was asleep and decided to take a nap in my room. Mistaking my aunt for my mother still makes me cringe to this day.

In fact, I mix up people all the time and sometimes I don’t even recognize myself in the mirror! Once, while I was on vacation, I had a long chat with someone who was staying in my hotel. The next day, I ran into him in the lobby and he said hi to me, which confused me, as I didn’t know who he was. My friends had to remind me that it was the person I had spent an hour talking to the night before.

Did you know? Your brain interprets faces differently than other objects. As a result, you might have trouble recognizing someone if their face were upside down, but find other upside down objects easy to identify.Still, it was not until I was 19 years old that I finally figured out I had a problem recognizing faces. This was after I’d taken several neuroscience classes and even learned about prosopagnosia! I think that it took me so long to realize that I had a problem because, like many others who have the condition, I can compensate very well by paying close attention to voices, hairstyles and other unique features that can be used to identify people. Another reason may be that I never had the full ability to recognize faces like everyone else, and I always assumed that everyone was just as bad at recognizing others!

Actually, people with other innate perceptual disorders like prosopagnosia tend to be like everyone else: they assume that everyone perceives the world in the same way as them. But it is important to remember that you can only see as much of the world around you as your brain allows you to see, and only in the way your brain interprets it. Ultimately, the world you perceive is merely your own brain’s unique reconstruction of what is really out there. Keep that in mind the next time an argument breaks out over the “real” colour of a car.

Learn more!

Resources freely available online

Information About Prosopagnosia (2015)
Centre for Face Processing Disorders, Bournemouth University

General introduction to the condition, its causes,  its impact on those affected and potential treatments.

Your Brain’s Facial Recognition Technology (2014)
Vanessa Hill, Braincraft
Video discussing how your brain recognizes faces, including the role played by the FFA and prosopagnosia.

Pareidolia: Why we see faces in hills, the Moon and toasties (2013)
BBC News

Pareidolia: Seeing Faces in Unusual Places (2012)
Kim Ann Zimmermann, LiveScience

Reports on how and why people often see faces in inanimate object.

The fusiform face area: a cortical region specialized for the perception of faces (2006)
N. Kanwisher & G. Yovel, Transactions of the Royal Society B: Biological Sciences 361(1476), 2109–2128.

Article discussing the role played by the FFA in recognizing faces.

Other resources

T. Gruter, M. Gruter & C. C. Carbon. (2008). Neural and genetic foundations of face recognition and prosopagnosia. Journal of Neuropsychology 2(1), 79-97.

Article discussing how the brain interprets faces and how this ability is affected by conditions like prosopagnosia. An abstract is available on the publisher’s website. A subscription is required to view the full text.

N. Hadjikhani, K. Kveraga, P. Naik & S. Ahlfors. (2009). Early (N170) activation of face-specific cortex by face-like objects. Neuroreport 20(4), 403-407.

Article discussing how the brain perceives faces in random patterns.  An abstract is available on the journal’s website. A subscription is required to view the full text.

N. Kanwisher, F. Tong & K. Nakayama. (1998). The effect of face inversion on the human fusiform face area. 1998. Cognition 68(1), B1-B11.

Article discussing how the brain recognizes (or doesn’t recognize) faces that are upside-down. An abstract is available on the publisher’s website. A subscription is required to view the full text.

Kiarash Salehigilani

I am a volunteer writer for CurioCity. I'm currently studying Biomedical Science and I am planning on continuing on to do my masters in perceptual neuroscience. My interests are in biology, medicine and neuroscience. In my spare time I like to play piano and travel. I love science because it makes you see things you thought you'd figured out in a completely new way.

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