RENEE MONTAGNE, host:
Now for a little mystery story, but this one isn't a whodunit - it's more of a who are you and it comes to us from our friends at RADIO LAB.
(Soundbite of various sounds)
JAD ABUMRAD: Hey, Renee.
MONTAGNE: Hello, there.
That's Jad Abumrad from WNYC. And Robert Krulwich, are you there?
ROBERT KRULWICH: Yes, I am here, too. And I should mention that RADIO LAB is a show where we get kind of curious, explore ideas, we argue sometimes.
ABUMRAD: And sometimes we like to tell stories that give us an unusual peek into the world around us.
MONTAGNE: Well, let's turn then to this mystery story. What is the nature of the mystery?
KRULWICH: Well, the first thing I should tell you is it's not just one today, it's two.
KRULWICH: Two stories.
MONTAGNE: Oh, okay.
ABUMRAD: Told by two different people.
Dr. V.S. RAMACHANDRAN (Neuroscientist, University of California, San Diego): I am V.S. Ramachandran at the University of California, San Diego.
Dr. CAROL BERMAN (Psychiatrist, NYU Medical Center): Okay, my name is Dr. Carol Berman. I'm at NYU Medical Center. I'm a psychiatrist.
ABUMRAD: And we start with Carol Berman.
Dr. BERMAN: My patient, who is this 37-year-old patient, comes back to her house and sits next to this man who's wearing a red plaid shirt, trucking boots.
ABUMRAD: She looks at this guy and she's just not sure what to make of him.
Dr. BERMAN: I think the jeans she recognized and the boots. And she takes a look at him and says: Who are you? And he says to her, well, who are you? Come over here and give me a kiss.
ABUMRAD: So she leans in, a little tentatively, gives him a kiss but it feels wrong. Everything about this situation feels wrong.
Dr. BERMAN: She was thinking, this is some strange man who's sitting here in, you know, her husband's clothing and she was wondering what he was doing in her apartment.
KRULWICH: Okay, so now we want you to hear a second story. This one comes from Dr. V.S. Ramachandran.
Dr. RAMACHANDRAN: I saw a patient not long ago, was in a coma two weeks - a student on our campus - came out of the coma, a little bit slowed down, but overall quite intact. But here's the problem: When he looks at his mother, he says Doctor, this woman looks exactly like my mother but she's an imposter.
KRULWICH: An imposter?
Dr. RAMACHANDRAN: She is an imposter. She's some other woman pretending to be my mother.
KRULWICH: Now, is this person his actual mother?
Dr. RAMACHANDRAN: It is his mother and it...
KRULWICH: He doesn't think that his mother is really his mother.
Dr. RAMACHANDRAN: Yah.
Dr. BERMAN: This person looked like her husband but there was something about him...
ABUMRAD: Like the feeling you have?
Dr. BERMAN: Right, the feeling or there's a certain essence and the soul of the person isn't in there.
ABUMRAD: So it turns out that these two people are suffering from the same delusion.
Dr. RAMACHANDRAN: Capgras delusion.
Dr. BERMAN: Pronounced Capgras.
ABUMRAD: Now, these kinds of Capgras delusions appear, sometimes, with brain injuries, or sometimes just out of the blue. But the result is almost always that you feel like your loved ones have been replaced by imposters.
MONTAGNE: Jad. Robert.
MONTAGNE: That sounds really...
(Soundbite of laughter)
MONTAGNE: I mean it has to be a rare thing, or at least I'm hoping it is.
KRULWICH: Well, we don't really know the exact numbers. It can go hand-in-hand with other disorders. So some doctors will look at it but then overlook it. It's certainly unusual.
MONTAGNE: And do we know why people with Capgras feel this way, why their brains play this trick on them?
ABUMRAD: Actually, no one is really sure why it happens but there are a couple of different ways of explaining what's going inside these peoples' heads.
Dr. BERMAN: We explain it psychologically - there might be some negative aspects of the person that you don't want to recognize. Like maybe my patient, you know, saw some negative things in her husband that she didn't want to recognize. So when the negative aspects came in, he had to be a completely different person...
Dr. BERMAN: ...for her to - 'cause she couldn't - you know what I mean?
ABUMRAD: So on some level, you think it's kind of denial.
Dr. BERMAN: Right.
ABUMRAD: So it would be like, Robert, if there was something about you that I just couldn't handle...
KRULWICH: You couldn't quite...
ABUMRAD: The only way I could deal with it, psychologically, was to make a break and to say, oh, well, that's not the Robert I know.
KRULWICH: Therefore, it isn't Robert at all. It's some fraud.
ABUMRAD: Yeah, it's a fake.
Okay, so that's the psychiatrist's explanation. Now here is how the neuroscientist explains it.
Dr. RAMACHANDRAN: I think what's happening is something quite specific. You can explain this in terms of the known circuitry in the brain. The visual centers in the brain funnel in information to the fusiform gyrus, where you recognize your mother or a dog, or a table or, a chair. Then their message goes to the amygdala, which gauges the emotional relevance of what you're looking at, for you.
KRULWICH: So, wait. So mom is a face I recognize as mom, and a set of feelings that I associate with mom.
Dr. RAMACHANDRAN: Correct. Absolutely. Now what happens is, in this patient because of head injury, that wire is cut.
KRULWICH: So then no mommy feeling.
Dr. RAMACHANDRAN: No mommy feeling. So you say, my God, if this is mom. She looks like my mom but I have no feelings. There's something really weird here. She must be an imposter.
Now that's a very farfetched delusion. Why doesn't she just say he doesn't feel like mom but, of course, she's my mom?
KRULWICH: Yeah, why doesn't he do that?
Dr. RAMACHANDRAN: Because our thought processes are much more dependent on our gut level emotional feelings than we realize.
KRULWICH: So absent a familiar feeling of mom, some part of my brain says that's your mother. And some part of it says no, it can't be.
Dr. RAMACHANDRAN: Yeah, and the equation that says it can't be, is from your emotions, wins.
KRULWICH: But now here's the twist.
Dr. RAMACHANDRAN: Now, if she goes to the next room and speaks to him on the phone, he says, Mom, where are you? How are you? It's wonderful to talk to you. Right?
KRULWICH: Why would that be?
Dr. RAMACHANDRAN: The reason is there's a separate wire going from the auditory regions in the brain to the amygdala, emotional centers. That wire was not cut.
KRULWICH: So what you hear can be very familiar. But if you see it then you got a problem.
Dr. RAMACHANDRAN: Yeah. We are highly visual creatures. We pay much more attention to vision, give much more weight to vision, than to hearing and to voice.
Dr. RAMACHANDRAN: So you say she sounds a little bit like my mother, I don't know why but she's obviously an imposter. And, of course, this is very alarming to the parents.
ABUMRAD: Tell me if you don't feel comfortable talking about this. But I understand that you have personal experience with Capgras delusions?
Dr. BERMAN: Yeah. Actually my husband, he started not recognizing other people first and then at some points he didn't even think I was his wife. I'm very sad and upset and stressed out by the whole situation.
You know, when I get home and I kiss my husband and say hi, how are you today, and I hope he's recognizing me. But you never know what you're going to get when you get back home.
MONTAGNE: Well, that was unexpected. Jad...
MONTAGNE: ...could you have thought any of that when you were speaking to her as a professional?
ABUMRAD: No, I mean that caught us off guard. Yeah.
KRULWICH: Can imagine what it would be like to be her? She has that at work and then she has that at home.
KRULWICH: Oh, God.
MONTAGNE: So is there anything that can be done to treat it?
ABUMRAD: You know, medication sometimes does help. But the truth is, for a lot of Capgras patients there's no treatment. And no amount of talk or reasoning seems to help.
MONTAGNE: That is Jad Abumrad and Robert Krulwich from the show RADIO LAB. It's a production of WNYC. And you can explore RADIO LAB at NPR.org.
This is MORNING EDITION from NPR News. I'm Renee Montagne.
MARY LOUISE KELLY, host:
And I'm Mary Louise Kelly.