Whether we discuss meditation from the standpoint of Buddhism or science, the power of meditative concentration is inconceivable.
American scientists once conducted an experiment in which the participants were Tibetan Buddhist practitioners of meditative concentration. The researchers utilized, on one side, brainwave patterns to measure changes in brainwaves, and on the other, magnetic resonance imaging to locate brain activity. In the end, they concluded meditation can not only change brain activity in the short term, it can, with great likelihood, change brain activity permanently. In other words, with meditation, one can completely eliminate anxiety, sadness, and other negative feelings, create a sense of happiness, even restructure the brain.
~ Depicted from THE PAPER TIGER - The Tibetan Buddhist View on Happiness