AYESHA RASCOE, HOST:
One day, Sadie Dingfelder had an epiphany in the grocery store. She spotted her husband with a jar of store-brand peanut butter. That hypocrite had just been extolling the virtues of homemade nut butters, so she plucked it out of his hands. Only that wasn't her husband. How did Sadie Dingfelder mistake a stranger for her husband and why? To find out, the freelance science journalist took a deep dive into her own brain. Her book is "Do I Know You?" And Sadie Dingfelder joins us now. Welcome to the show.
SADIE DINGFELDER: Thanks for having me.
RASCOE: Before we get into the science of your brain, you always kind of knew that you were a bit quirky. Can you explain what it's like to be inside your head?
DINGFELDER: Yeah, I had no idea, but it turns out that my experience of human consciousness is pretty unusual. I don't have an inner monologue. I can't visualize at all. I can't do mental time travel to moments from my past, and I can't tell the difference between faces very well.
RASCOE: You can't visualize anything. So if I said visualize a beach right now, don't nothing pop up in your head?
DINGFELDER: Nothing. And I never realized other people could do it.
RASCOE: (Laughter) The thing is you don't grow up knowing that you're having this vastly different experience from other people. Like, you just thought maybe you were bad at faces.
DINGFELDER: Right. That's what the secret message of my book title is. It's "Do I Know You?" because it turns out that, your husband, your best friend, your boss - they may be having a completely different conscious experience than you, and they may have completely different perceptions than you, even though we all live in the same objective environment.
RASCOE: So, you decided to find out why you have so much trouble with faces. Exactly how many scientific studies did you sign yourself up for?
DINGFELDER: I know I've worked with five different teams of researchers across the country. I should have counted the number of published studies I've been in now.
RASCOE: So what did you find out about your brain?
DINGFELDER: Well, it turns out that all humans have this thing called the fusiform face area or the FFA, which is an almond-shaped chunk of brain matter just above your ears. And my FFA did not get the neural pruning that it needed when I was a baby. As a result, it's too thick. And so I didn't learn to specialize in human faces as well as other more neurotypical babies.
RASCOE: OK, so that was a lot of big words. So there's this area in your brain...
DINGFELDER: Yeah.
RASCOE: ...That as you get older, it kind of gets thinner...
DINGFELDER: Yeah.
RASCOE: ...To kind of focus a bit, and yours didn't.
DINGFELDER: Exactly. And you know what else is really neat about this fusiform face area is that it seems to hold within it a very basic face template. Fetuses that are pretty on the older side, if you like, shine lights, two dots above a line on the mother's stomach, the fetus will focus on the face-like pattern and track it, and it will not focus on an upside-down face pattern. And what I learned is that it's not so much that I'm bad at faces, it's that most humans are just astonishingly good. Most humans have a near photographic memory for faces. And not for other types of objects. Like, if I showed you a seashell, and then I put that seashell in a lineup like 20 minutes later. You would probably have a lot of trouble picking it out. But you could do that with a face, no problem.
RASCOE: You also found out in the book that monkeys do something similar...
DINGFELDER: (Laughter).
RASCOE: ...But with butts.
DINGFELDER: Yeah. Monkeys can tell their friends from their foes by their - it's called the anal-genital region. But yeah, monkeys tell each other apart by their butts, basically. They can also tell by faces, though. They can do both. Humans can only do faces. And they tested it. Someone tested this.
RASCOE: (Laughter) You not only discovered that you had this face blindness, but there are other things that you found out too about yourself.
DINGFELDER: Yeah. So once I figured out I was faceblind and sort of accepted it, which took a minute, I was like, but why am I faceblind? Because for most people, it's genetic, but I couldn't find anyone in my family who was also faceblind. So I tracked it back, I think, to the fact that I'm stereoblind, too, which means that I do not see in three D, which is something that I kind of knew about myself, but I hadn't really thought through before. But my world is so much flatter experientially than most people's world. And that's why I cannot catch a Frisbee or I get stressed out driving.
RASCOE: Oh, my goodness. Seems like with all of these things, you're coming to realize that you have them now, but you've had them, like, all your life. What strategies did you realize you had been using to make up for the way that your brain works?
DINGFELDER: As a reporter, what I do is I - right at the top of every notepad, I always have written - write down sensory details. Because if I go into a situation and talk to scientists and see their lab, I'm going to remember the big picture things, but I'm not going to remember what it smelled like, what it sounded like, the color of the carpet. I mean, there's definitely some clear disadvantages to being a faceblind journalist. I have some funny stories of failing to recognize people that I've just been interviewing. But on the positive side, I have a lifetime of experience just like making a quick connection with a stranger because I'm curious about them. I'm curious if maybe they are a good friend of mine or a stranger.
RASCOE: Yes.
(LAUGHTER)
RASCOE: With this book, when you're reading it, you start thinking, like, do I have any of this? Now, like, I see the world in 3D, but I feel like when I'm driving, I can't tell how far away things are from me.
DINGFELDER: Yeah.
RASCOE: Say, if I'm trying to parallel park, it will take me like 20, 30 minutes, and I'll just keep pulling up and I'll be like, I know I'm close this time, and I'm still, like, five feet away. Do you know what that is? Is there a name for that?
DINGFELDER: Yes. I mean, all of these things are on a spectrum, and I just happen to really be pinning down the far side of the spectrum. Now, I'm stereoblind, but you can definitely be stereo deficient. It's very common.
RASCOE: Oh. OK.
DINGFELDER: People don't realize that vision is not just about acuity. It's also about like, assessing depth. If you go to the optometrist, they can test it, and you can find out. And also, you can improve it. I got to try out these new, just barely FDA-approved therapies that are on virtual reality goggles where you play video games, to improve your stereo acute. And mine got a lot better. And I put a key in my door on the first try for the first time in my life.
RASCOE: But then I'm afraid if I go in and try to see if I'm diagnosing, they're like, you're totally fine, then does that just mean I'm a bad driver?
DINGFELDER: Yes.
RASCOE: OK.
(LAUGHTER)
RASCOE: Well, then that's the question. Do you want to have the diagnosis or do you not want to have the diagnosis? Do you think it's better to know or to not know?
DINGFELDER: You know, I've been back and forth on this a few times, but I've landed on, it's better to know. And most people who are faceblind, do find that it allows them to see their life with sudden clarity. It's almost like putting on glasses because all of a sudden, all of these mysteries that you've always been wondering about kind of click into place. For instance, I had a good friend who I thought moved away between middle school and high school, and it turned out she just got bangs, so...
RASCOE: OK (laughter). You just - you didn't recognize her anymore, and she just thought you were, like, being standoffish.
DINGFELDER: Yeah, yeah. It's kind of tragic, and it's also a little funny.
RASCOE: What is your relationship with your brain like today? Do you appreciate your brain for being unique and quirky? Are you resentful? Have you made peace with everything?
DINGFELDER: Oh, I am just in awe of not only my brain, but everyone's brains. Even when they're not working at full capacity, the amount of calculus and like, physics and all of these calculations that your brain is doing constantly behind the scenes - it's like a miracle a second. And I love learning more about the brain because it really makes you appreciate, you've got this, like, three-pound marvel in your skull that we all just take for granted.
RASCOE: That Sadie Dingfelder. Her book is "Do I Know You?: A Faceblind Reporter's Journey Into The Science Of Sight, Memory, And Imagination." Thank you so much.
DINGFELDER: Thank you. It was great talking to you, Ayesha. Transcript provided by NPR, Copyright NPR.
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