RENEE MONTAGNE, HOST:
Let's get an update, now, about something we heard a year ago in the series Joe's Big Idea. It's a computer game designed by a scientist to help map all the connections of nerve cells in the eye. Now, that scientist says the game is working, as we learn from NPR's Joe Palca.
JOE PALCA, BYLINE: The scientist is Sebastian Seung at the Massachusetts Institute of Technology. The game he invented is called Eyewire. Instead of fighting aliens, the players have to pick out specific cells in picture of tissue from a part of the eye called the retina and color them in. As he told me a year ago, he needed to recruit a lot of gamers to play his game because the retina is a jungle of entangled branches of neurons.
SEBASTIAN SEUNG: And we need an army of people to go out and explore that jungle.
PALCA: To recruit players, he came up with a sales pitch. Since the eye sends signals directly to the brain, the game is providing crucial information to neural scientists about how the brain works.
SEUNG: What could be more exciting than exploring the brain? Much more exciting than any artificial video game.
PALCA: Well, the pitch worked. A lot of people signed up to play the online game.
SEUNG: Over 120,000 citizen neural scientists from 140 countries.
PALCA: That's Seung speaking via his Smartphone a few days ago while he was on a trip to South Korea. Each player gets a high resolution picture of a different section of the retina to color. The trick to scoring point in the game is to only color the parts of the image that are nerve cells. This is something that's surprisingly difficult and humans are actually better at it than computers.
Back at Seung's lab, a computer takes these colored sections and reassembles them. This produces a three-dimensional image of how all the neurons connect with each other. Seung says you can think of it as a kind of cellular wiring diagram.
SEUNG: And this wiring diagram may finally be the solution to a problem that has eluded neuroscientists for 50 years, literally 50 years.
PALCA: In the old days, people thought of the eye as more like the lens of a camera that just captures an image and sends that image to the brain. And the brain does all the work of making sense of the image, letting us see the world.
SEUNG: But it turns out that some of the first steps of perception are actually happening inside the retina itself, even before the information reaches the brain.
PALCA: Scientists have known that for 50 years. What they didn't know was how the retina did it. When Seung looked at the wiring diagram his army helped produce, he realized it showed there were neuropathways that would enable the retina to detect motion. The results appear in the prestigious journal Nature. Seung has a lot more work for his Eyewire gamers to do because he says the paper in Nature proves that citizen neuroscientists can really make a big impact on brain science. Joe Palca, NPR News. Transcript provided by NPR, Copyright NPR.