How the brain sees in three dimensions.

When Renaissance painters solved the problem of depicting three-dimensional (3D) scenes on flat canvases, their paintings blossomed into realistic representations of the world. Our brain must solve this problem every day to reconstruct 3D views from images that fall on the 2D surface of our retinas. Researchers have long known that we use various cues to accomplish this, such as the stereoscopic effect of binocular vision and the relative sizes of objects. Now, a team at the California Institute of Technology in Pasadena has made a surprising discovery about the neurons that apparently translate distance cues for the brain.