Demystifying meditation -- brain imaging illustrates how meditation reduces pain

"We found a big effect – about a 40 percent reduction in pain intensity and a 57 percent reduction in pain unpleasantness. Meditation produced a greater reduction in pain than even morphine or other pain-relieving drugs, which typically reduce pain ratings by about 25 percent."
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The scans taken after meditation training showed that every participant's pain ratings were reduced, with decreases ranging from 11 to 93 percent, Zeidan said.  link