When you stub your toe or bang your head, why is the initial response always to yell "ouch" (or something less printable)? Scientists may have the answer.
New research from the National University of Singapore suggests that vocalizing may interfere with pain signals traveling to the brain, distracting you from the uncomfortable sensations you're feeling.
The researchers gathered 56 test participants and had each person submerge his or her hand into painfully cold water four separate times. In each case, participants were asked either to say "ow," to listen to a recording of a person saying "ow," to press a button or to remain passive and silent.
Both saying "ow" and pressing the button were found to have a positive effect on pain tolerance. When participants said "ow" or pushed a button, they were able to withstand the pain for an average of 30 seconds, compared to an average of 23 seconds among participants who did neither. Sitting passively, on the other hand, did not improve pain tolerance. Nor did hearing a recording of someone saying "ow," whether it was the participant's own voice or someone else's.
The findings suggest that making some kind of vocal utterance may be an effective way of coping with pain.
The researchers hypothesize that the effect may occur largely through motor processes. The muscle movements required to cry out loud (or to push a button) may disrupt pain messages as they travel from the area affected to the brain.
"When you move... you're aware of what you're doing," Dr. Daniel Carr, director of the Pain Research, Education and Policy program at Tufts University School of Medicine, said in an email to The Huffington Post. "The awareness of what's happening in the body during the process of making a noise, or doing anything that's active -- that awareness interferes to some degree with the awareness of the pain."
While the findings are certainly suggestive, more data is needed to determine the extent to which vocalizing helps boost pain tolerance in different situations, and whether the findings apply to chronic as well as acute pain.
"While there is a statistical significance, the actual change in seconds wasn't really a huge effect... we're talking about a modest but discernible effect," said Carr, who was not involved in the Singapore team's research. "But this looks to me to be a legitimate finding and a well-designed study."
The findings appeared in The Journal of Pain last month.