美国国家公共电台 NPR How Science Is Rewiring The Dyslexic Brain

How Science Is Rewiring The Dyslexic Brain 

play pause stop mute unmute max volume 00:0004:46repeat repeat off Update Required To play the media you will need to either update your browser 1 to a recent version or update your Flash plugin. DAVID GREENE, HOST: 

OK, this morning we're also learning about the most common learning disability - dyslexia. Gabrielle Emanuel of the NPR Ed team takes a look at the science, what's going on in the brain.

GABRIELLE EMANUEL, BYLINE 2: Tiffany, who is 8, is in the basement of one of Georgetown University's medical buildings here in Washington, D.C. She's snacking on Goldfish between sessions in an MRI scanner that measures brain activity.

Do you know what they're doing?

TIFFANY: They're taking pictures of my brain.

EMANUEL: Why do they want to see your brain?

TIFFANY: So they can see how big or small it is. My brain is big (laughter).

EMANUEL: I bet it is.

Tiffany is a sharp kid. That's why her family was so confused when they heard her second grade teacher wanted her to repeat the grade. At the time, Tiffany was living with her dad in the panhandle of Florida. When her aunt up in Virginia, Billie Joe Bevan, heard about this, she was shocked.

BILLIE JOE BEVAN: And I was like, retain her? That didn't make any sense because here Tiffany is so kind of precocious 3. And she's so good in math.

EMANUEL: Bevan says Tiffany's a good kid and a good student, but reading is really hard for her.

BEVAN: And that's when I jumped in and said whoa, whoa, whoa, whoa, we need to go for additional testing.

EMANUEL: When school let out for the summer, Tiffany moved to Virginia to join Bevan's family and get tested. They found out she has dyslexia and that she qualifies for a research study, one that looks at what makes brains with dyslexia different.

UNIDENTIFIED WOMAN #1: Tilt 4 your head so it's straight - there you go.

EMANUEL: Having finished her bag of Goldfish, Tiffany's now in the room with the MRI scanner. She's lying flat on her back.

UNIDENTIFIED WOMAN #1: You ready to go in?

TIFFANY: Yes.

UNIDENTIFIED WOMAN #1: Here we go.

EMANUEL: Inside the big circular MRI machine, Tiffany does tasks, things like quickly deciding whether a word has a tall letter in it. As she does this, researchers watch to see what parts of Tiffany's brain are more active.

GUINEVERE EDEN: You can think of the reading brain as moonlighting.

EMANUEL: Guinevere Eden directs Georgetown's Center for the Study of Learning.

EDEN: It's doing a job it wasn't really supposed to be doing.

EMANUEL: Eden says human brains are designed to learn spoken language, not so for reading. So as we teach ourselves to read, we co-opt areas of the brain that were meant to do something else and we use them for reading. There are two key areas - both on the left side of the brain. One is for a spoken language. We use it to sound out words.

EDEN: Then after you've done that a few times, you begin to say, well, hang on, I've done this one before. And it seems that your visual system then just recognizes it by sight.

EMANUEL: That's the second area of the brain involved in reading, part of the visual cortex at the base of the brain, behind our ears. Its original purpose was to recognize objects, like a toaster or a chair. But we train it to recognize letters and words. There are sight words like the, and, it. So what happens in dyslexia?

EDEN: Both areas are underactivated.

EMANUEL: Those two areas don't light up quite as much as in a typical reader. Eden decided 5 to try something. She got people, like Tiffany, to do a six-week intervention 6.

EDEN: Six hours a day, five days a week.

UNIDENTIFIED WOMAN #2: Take a picture of the word meal. If I erase 7 the A in that word, what word would we see?

TIFFANY: Uhm...

EMANUEL: During the intervention Tiffany worked with a tutor.

TIFFANY: A - can I see it again?

UNIDENTIFIED WOMAN #2: Take a good picture.

TIFFANY: It would be meal.

UNIDENTIFIED WOMAN #2: OK.

TIFFANY: No, it would be male. No, maaal (ph).

UNIDENTIFIED WOMAN #2: Good - what sound...

TIFFANY: I can't...

UNIDENTIFIED WOMAN #2: ...Does one E make by itself? Do you remember?

TIFFANY: Mel.

UNIDENTIFIED WOMAN #2: It'd be mel - very good, nice job.

EMANUEL: This type of manipulation is very hard for people with dyslexia. But over the course of the six weeks, the research subjects practice a lot, and the researchers can tell. When they take brain scans after the intervention, the areas typically associated with reading have become more active. And Guinevere Eden says something else happens, too.

EDEN: Other areas became more active, and they're not areas that we think of being involved in reading. They were in the right hemisphere.

EMANUEL: These areas on the other side of the brain start chiming in and helping 8 out. Eden has already done a study like this in adults. Now she's studying Tiffany and 47 other kids over five years.

If her earlier findings hold up, it suggests intensive reading help is worthwhile. It can change how our brains read. Tiffany's aunt, Billie Joe Bevan, says she already sees a difference every day when they read before bed.

BEVAN: I can see so many gains.

EMANUEL: Tiffany's reading has improved and so has her self-esteem. Gabrielle Emanuel, NPR News.