What it's like to have prosopagnosia, or face-blindness

New York Magazine interviews an anonymous 47-year-old woman about her condition:

It doesn’t matter if I know the person: I’ve walked right past my husband, my own mother, my daughter, my son, without being able to recognize them.

It can be very embarrassing, and it can offend people. I once had to drop a sociology class, because I told the professor, to her face, that she was a horrible lecturer. I thought I was complaining to a fellow student! It’s as if I have a missing chip — you feel like you’re just not trying hard enough. Faces are so important to humans that we have a special part of our brain dedicated to recognizing them. Most people remember them as a whole piece, but I don’t. . . . Good-looking people are the most difficult to recognize. . . .

The other thing I have discovered is that there is a specific expression people have when they see somebody they know. I call it the “I know you face” — it’s sort of a surprised micro expression. I’m convinced that it’s completely involuntary. It looks a little like surprise. The eyebrows go up, and usually the mouth opens like they're about to say something. When I see it, I say hello, and then when I start interacting with them, I’ll remember who they are. That’s just one of a whole set of observational skills I’ve developed. Another is when I’m meeting somebody in public, I’ll arrive early so they'll approach me.

I'm always looking for visual hooks. My daughter has a particular thing she does with her mouth. If there’s several people who could be her, I look for the mouth thing. If she's nervous, or she's irritated, one side of her mouth goes up. She's done it since she was a baby. She doesn't like having her photograph taken, so when I look at a group photo, I look for the kid with the smirk and I know it’s my daughter. . . .

My son had a distinctive blue and white camouflage hat that he wore for five years. It was great for me when we were in the playground because I could track him. The rule was that my kids had to keep me in their line of sight. If there was a crowd of kids and mine weren’t wearing anything distinctive, I was totally lost. . . .

I’ve had to say to friends of mine, “Is that a picture of me? Who is that?” If I unexpectedly see myself in a mirror, I might think it's somebody else. It's like, Why is that woman staring at me? . . .

When I worked at a homeless shelter, I was often praised for the way I interacted with my African-American clients. I couldn’t figure out what I was doing differently from the other white workers, but I was allowed into their circle and they bonded with me. When we lived in Louisiana, I was always being asked by African-American women if my husband was black. When I was tested at Dartmouth, I scored low on unconscious racism. Apparently babies show a preference for their own race at about nine months because that’s when they start being able to recognize faces. My head doesn’t do this.