3-D technology was once the territory of hokey sci-fi and horror movies. But as the technology's gotten better, we're apparently going to see more of it. Tim Burton's forthcoming Alice in Wonderland film, for instance, will be released in 3-d (It's Alive! doesn't get all the hype about this movie - it looks like every other Burton-Depp movie we've seen).
Anyway, exactly what is it in the brain that allows us to see flat images as if they're in three dimensions?
Oddly, 3-d motions is processed in the part of the brain once thought responsible for processing 2-d images. So says Alexander Huk at the University of Texas. It's the area behind the ears known as MT+.
There's a a mismatch between what the two eyes see, so when an object moves toward you, the brain calculates the change in time in this mismatch. This happens in the MT+ area.
The study was published in Nature Neuroscience.