Washington: Research conducted at the Wake Forest University Baptist Medical Center has confirmed that sensitivity to pain varies from individual to individual.

The researchers used magnetic resonance imaging (MRI) to assess brain function, and found that study participants who found a heat stimulus intensely painful had pronounced activation of brain regions related to pain. In contrast, people who said that the same stimulus was only mildly painful had minimal activation of these same areas.

For the research, 17 normal, healthy volunteers including eight women and nine men had a computer- controlled heat stimulator placed on their leg. This device heated a small patch of their skin to 120 degree Fahrenheit, while their brains were scanned.

It was observed that all the participants reported different experiences of pain.

The finding showed that incoming painful information is processed by the spinal cord in a generally similar manner. But, once the brain gets involved, the experience becomes very different from one individual to the next.

"These findings confirm that self-reports of pain intensity are highly correlated to brain activation and that self-reports should guide treatment of pain," says Cognill, lead investigator of the study.

He also believes that most individual differences in pain sensitivity are probably due to a combination of cognitive factors, such as past experience with pain, emotional state at the time pain is experienced, and expectations about pain. He is also looking at how a person's expectations about pain influence the pain they actually experience.

ANI