Piece of Mind - This diagram maps 1 cubic millimeter of the brain-but its unprecedented clarity deepens the mysteries of cognition.

This diagram maps 1 cubic millimeter of the brain-but its unprecedented clarity deepens the mysteries of cognition. Although this image wouldn't look out of place on a gallery wall alongside other splashy works of abstract art, it represents something very real: a 1-cubic-millimeter chunk of a woman's brain, removed during a procedure to treat her for epilepsy. Researchers at Harvard University stained the sample with heavy metals, embedded it in resin, cut it into slices approximately 34 nanometers thick

- By Isabel Fraser