Studies into the effects of stress on the human body have demonstrated that the
neurons in the hippocampus (a part of the brain responsible for day-to-day memory
and new learning) can shrink. Dendrites, the connecting wires between brain cells,
have been known to permanently shrivel in response to negative thinking. On the
other hand, love, affection and happy moods can increase our ability to solve
intellectual and practical problems. The positive thinker's answer to: "Can you play the
piano as well as Barenboim?" is not: "No, I can't," but: "Not yet.