Obama announces brain-mapping plan. Scientists decode dreams with brain scans. The active ingredient in magic mushrooms could treat severe depression, but conducting trials is a legal nightmare. A turtle believed extinct for decades never really existed. How nerve cells generate energy. Buzz Aldrin's toothbrush, and other space memorabillia, up for auction. And a new species of giant tarantula has been discovered and is "pretty", venomous, and the size of your face.