The brain, like the rest of the body, has a remarkable degree of bilateral symmetry. It is helpful to think of it as an enlarged walnut. One side is not the exact mirror image of the other, but approximately so. Almost every brain structure has two copies, one on the left and one on the right. The left side of the visual field is represented by the visual cortex in the right hemisphere, whereas the right side is mapped onto the left visual cortex. When you look out at the world, you don’t see a fine vertical line running down your field of view; the two hemifields are integrated seamlessly.
...more
