对着镜子自我鼓励为何有效？

RACHEL MARTIN, HOST: There are a lot of videos on YouTube that encourage women to take control of the messages they're sending themselves, videos like this one.

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LORI OSACHY: Are you getting in front of the mirror and saying, wow, I look great today; I'm a wonderful person; I look fabulous? Or are you picking your body apart and talking about, you know, how big your butt is or how scrawny your arms are or, you know, the millions of negative messages...

MARTIN: That was the voice of Lori Osachy. She's an eating disorder therapist in Florida. And we heard her there, leading a session in a self-help technique known as self-talk.

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OSACHY: That's your assignment for today, for tip number one. Practice only allowing yourself to say positive things when you look in the mirror.

MARTIN: For our series The Changing Lives of Women, we asked NPR's Laura Starecheski to separate the science of self-talk from the talk.

LAURA STARECHESKI, BYLINE: By browsing YouTube videos and self-help books, I've learned that saying nice things to my reflection in the mirror will make me sexier, more successful, have better relationships. It can even help me start a money-making business and chase dreams I never even knew I had.

So I took this self-talk thing to one of the country's leading researchers on body image. David Sarwer is a clinical director at the Center for Weight and Eating Disorders at the University of Pennsylvania. And a mirror turns out to be one of the first things he puts in front of new patients.

DAVID SARWER: What we'll often do is have them stand in front of a mirror and try to use different, more neutral language in terms of evaluating their bodies. Instead of saying, you know, my abdomen is disgusting and grotesque, to get them to say, my abdomen is round; my abdomen is big; it's bigger than I'd like it to be - but to reframe it and to take some of those very negative and pejorative terms out of the self-talk that they're engaged in.

STARECHESKI: It's not enough for a patient to lose weight or gain it, as the case may be, if she doesn't also change the way her body looks in her mind's eye. This may sound weird because weight is physical; you're either a size 4 or size 8. But in a study done last year in the Netherlands, scientists watched women with anorexia as they walked through doorways in a lab. The scientists noticed that the women turned their shoulders and squeezed sideways even when they had plenty of room.

BRANCH COSLETT: Their internal representation - their brain perspective on their body - is that the body is much, much bigger than, in fact, it is.

STARECHESKI: That's Branch Coslett, a cognitive neuroscientist at the University of Pennsylvania. He says studies like this one aren't actually new.

COSLETT: Discussions of these kinds of things goes back to a series of beautiful papers in the journal "Brain." This guy Holmes and Head - these two famous neurologists.

STARECHESKI: The aptly named Henry Head and Gordon Morgan Holmes explored the body-brain connection way back in 1911. But they didn't look at people with anorexia.

COSLETT: They used an example of the kinds of hats that were then in vogue, which were these big hats with big feathers at the top. They were talking about how these women who were wearing these hats habitually, when they go through doors, would duck even if they're not wearing their hat.

STARECHESKI: Their mental self was wearing the hat, even if their physical self wasn't - just as anorexic women in the Netherlands study saw themselves carrying a bigger body. Neuroscientists are still trying to understand exactly how this works. One thing they do know is that we all have an internal representation of our bodies. We need it to walk and not bump into things, to do simple tasks like pick up a cup of coffee. What Coslett wants to understand - and he's actually just starting to research this now - is how people with eating disorders get their mental body so wrong, adding inches to their thighs, butts and bellies. When you think like a neuroscientist, talking to yourself in the mirror isn't just a confidence booster; it's more like internal remodeling.

COSLETT: We create internal representations that are very different from the world. So if you can take somebody and say, I believe that my body type is sexy, is cool, is desirable, I think that's going to influence what they see.

STARECHESKI: I am cool. I am desirable. I'm going to do an amazing job at this next interview. I'm not quite convinced, and I'm not alone in this. When you're talking to yourself and you use the word I, you might stress yourself out more.

ETHAN KROSS: If I'm really stressed out about this interview that I've got to do, rather than thinking about, oh, my goodness, why am I feeling this way? You might just use your own name and say, well, why is Ethan feeling this way?

STARECHESKI: Ethan Kross is a psychologist at the University of Michigan. He studies the pronouns people use when they talk to themselves silently, inside their minds.

KROSS: What we find is that that subtle linguistic shift - shifting from I to your own name - can have really powerful self-regulatory effects.

STARECHESKI: Self-regulatory meaning you can change the way you feel and behave. Kross had this idea when he was driving in the car and - his words - did something not smart, like run a red light.

KROSS: And I immediately said to myself, Ethan, you idiot.

STARECHESKI: But because he's a psychologist, Ethan, you idiot turned into, huh, that's interesting. Why did I talk to myself in the third person using my own name? Then he started noticing people doing this all the time. Here's just one example, LeBron James in 2010, talking about his decision to leave Cleveland for the Miami Heat.

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LEBRON JAMES: One thing that I didn't want to do was make an emotional decision, and I wanted to do what was best, you know, for LeBron James and what LeBron James is going to do to make him happy.

STARECHESKI: LeBron James says he doesn't want to make an emotional decision. He then literally creates distance from himself in his language. Kross did an experiment to see what would happen if non-famous people tried this. He asked people to give a speech with only 5 minutes of mental preparation. One group was then told to talk to themselves using I and another group to use you or their own names. Kross says that people who used I had a mental monologue that sounded something like this.

KROSS: Oh, my God. How am I going to do this? I can't prepare a speech in 5 minutes without notice. It takes days for me to prepare a speech.

STARECHESKI: People who used their own names, though, tended to give themselves support and advice.

KROSS: Things like, Ethan, you can do this. You've given a ton of speeches before.

STARECHESKI: They were more rational and less emotional. I actually tried this. I went into my bathroom, sat on the edge of the tub, closed my eyes and talked to myself.

Laura, you're doing a great job with this story.

And when I used my own name, that other person began to take shape in my mind's eye.

Laura you've got some really interesting ideas in here.

I sort of saw myself in the room, from a fly-on-the-wall perspective. There I was, a mini version of me, sitting on the edge of the bathtub. Turns out this happens to other people, too.

KROSS: We've done studies that look at exactly that phenomenon, and your experience is borne out by our data.

STARECHESKI: Kross says that using your own name actually leads you to see yourself from an outside point of view.

KROSS: It's almost like you are duping yourself into thinking about you as though you were another person.

STARECHESKI: And being an outsider has real benefits - objectivity is one - like Lebron James would tell you. And it turns out it's a lot easier to be kinder with that other person. Laura Starecheski, NPR News.