07 March 2004

More on contextual features in pain perception

The NY Times elaborates on the study I mentioned below. Link

By DINITIA SMITH
Published: March 6, 2004
When David Williams, a psychologist at the University of Westminster in London, was deciding how to construct a pain machine, he realized a kitchen scale would do the trick. He attached a guillotinelike device to it, though he hastens to point out that the edge was "really blunt, not as sharp as a razor." It was designed to hit at the fingernail's half moon, where one can inflict pain without doing serious bodily harm.

He was trying to figure out what influences the perception of pain. What he discovered was that both men and women were willing to take more pain from a woman than from a man.

"A person's perception of pain doesn't necessarily depend on the intensity of the stimulus," Mr. Williams said in a telephone interview from his home in Stevenage, 30 miles north of London. It depends on environmental factors, like who is inflicting it. The 40 people who were tested waited longer to say "stop" when a woman was causing the pain than when a man was.

"The stereotype we have of women is that they are nurturing, caring, sensitive, that they have empathy," said Mr. Williams, who administered the experiments for his doctoral dissertation. "We feel safer with them."

In another experiment he looked at what you could call the pre-pain conversation. First he measured a subject's pain threshold. Then he told the subject that there was no need to say "stop" because he already knew exactly how much the subject could take. "The consequence was very odd," Mr. Williams said. When people were denied control, they felt the hurt as more intense.

Next Mr. Williams told subjects that he would not say exactly how much discomfort he was going to inflict, and again there was no point in telling him to stop. "When they were denied control and information," he said, "60 percent said it was less painful, 30 percent said it was more painful."

Mr. Williams theorizes that the different responses were a consequence of people's sense of control in their lives. Those who see themselves as in control experienced less pain, while those who tend to believe their lives are controlled by others or by chance experienced more.

By saying, "This is going to hurt a bit, try to hang on," doctors may actually make the patient feel out of control, he said.

And, yes, d├ęcor matters. In another experiment he found, not surprisingly, that graphic pictures of wounds hanging on the walls made people call it quits earlier. Therefore redecorating hospitals to make them less threatening to patients makes sense, Mr. Williams said. The smell of pine disinfectant is pervasive, and machinery and medical instruments are in full view.

"Only an operating room needs to be that clinical," he said. "The smell, the look, the whole appearance, everything which says, `This is a hospital, and you have no control. You are here to suffer' — all are changeable."


Again, I think these results are extremely important to our understanding of pain and how it is bad. I'll post something later to set out some of the philosophical issues I believe they bear upon.