People who meditate regularly feel an enviable sense of calm. Neuroscientists have shown that by altering brain-wave patterns, the discipline purges negative thoughts. Experienced meditators are calmer in their response to daily stress and perform better at tasks that require focused attention. A handful of researchers think the same brain changes could even confer physical benefits, such as lowering blood pressure and preventing disease.
Scientists, as well as practiced meditators such as the Dalai Lama, also want to know how much meditation is needed to achieve these gains. What if 20 minutes, twice a day, were enough? A person could add that to his or her daily routine of 30 minutes on the treadmill and achieve physical and mental harmony.