How much pain one experiences depends on expectations

The amount of pain that a person experiences depends not only on what is causing the pain, it also varies greatly with how much pain the person expects to receive from it.

Scientists at Wake Forest University School of Medicine recruited 10 volunteers to study activation of various areas of the brain prior to and during painful heat pulses that were applied to the legs of the volunteers. The device that caused pain induced no tissue changes or burns.

What the scientists were trying to find out was whether or not the expectation of pain affected how much pain was actually experienced by the individual.

Before initiating the actual testing, volunteers were trained, being told that seven seconds after they were notified a mild painful stimulus would be rendered; 15 seconds after notification a moderate stimulus would be rendered, and 30 seconds after notification a pronounced amount of pain would be applied through the device attached to their legs.

Once training was complete, they each underwent 30 trials. In one-third of those trials, the interval between notification and pain was changed, so that it did not correlate with what was expected.

Researches discovered that the expectation of pain lit up the same areas of the brain on functional MRI scans as were triggered by the actual application of the painful stimuli. If the person expected only moderate pain, but got severe pain instead, the amount of pain that they actually reported was 28% less than that which was expected. This reduction in pain was equivalent to the relief that has been reported in response to morphine. In other words if a person expected pain to only be moderate, they tended to not feel as much pain as if they expected that pain to be severe.

Bower, Bruce (2005). “Thinking the Hurt Away.” Science News. 168 (11): 164-5.

Posted on 1/16/2007 under Christian Health & Medicine, Faith, the Bible and Medicine. Comments RSS feed.
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