pain » The Thinking Meat Project

Vicarious experience

Psychology Comments Off

Mar 202007

Just watching a video of someone else encountering a painful stimulus can lead a person to react physically to the same stimulus himself, according to a new study. Participants watched a video of someone who had learned that every time a blue square appeared on his computer screen he would get shocked, but that yellow squares were harmless. It was obvious from the video that the person was expecting the shock. After seeing the video, the participants were set down in a similar situation, and when blue squares appeared on their computer screens they tensed up, even though they never received a shock. Their brains–specifically, their amygdalas–even appeared to be reacting, as they would if the subjects had learned through direct personal experience. This article from Live Science gives some details.

And on a slightly different note, this press release from Brandeis University discusses some research into how people learn sequences of physical motions. When people were given a series of motions to learn and repeat, they did as well by watching the sequence several times and then trying to reproduce it themselves as they did when they tried to imitate it after each viewing. In other words, they learned just as much by watching as they did by watching and imitating. (So maybe if I watch an exercise video over and over I’ll learn the steps? It sounds too good to be true.) There’s more in the press release about how this type of research could be applied to improve the way physical skills are taught.

The dread can be worse than the pain

Psychology 6 Responses »

May 062006

I wonder how much they had to pay the volunteers for this experiment. Researchers at Emory applied electrical shocks to test subjects’ feet, letting the subjects know how painful they were going to be (as a percentage of the person’s individual pain threshold) and when they would be administered. When they were given a choice between more painful shocks sooner, and less painful shocks later, volunteers described as “extreme dreaders” were willing to put up with more pain if they could just get it over with sooner. The test subjects were scanned with fMRI, and the results illuminated the nature of dread and a possibility for mitigating it. The areas of the brain that were active when a subject was dreading an upcoming shock were not the same as those active in fear or anxiety. Instead, they were part of the brain’s pain network, in particular, the part that is associated with attention. So dread is not the same as fear, but seems to stem from the way a dreaded event fills our attention, and thus focusing attention elsewhere might be a good way to alleviate dread. I can see how that might work. I try to bring engrossing books when I travel so I won’t think so much about how much I hate flying (not just on the plane but while waiting to board), but on the other hand I know that I shouldn’t bring anything too demanding because my feeling of impending doom is so intense that it’s hard to think about anything else. This research was part of a neuroeconomics program, which was a little surprising to me; the idea is to learn more about the way we make decisions about unpleasant future events.

Here’s a press release from EurekAlert and an article from the New York Times (free registration required).

Biofeedback for the 21st century?

Brain and mind Comments Off

Jan 072006

If you could use an fMRI (functional magnetic resonance imaging) scanner to keep an eye on your rostral anterior cingulate cortex (a place in your brain where sensations of pain are processed), would you be able to change anything about how you feel? Maybe so. A recent study of volunteers with chronic pain showed that they could reduce the amount of pain they felt if they used techniques for changing how they think about the pain while observing real-time fMRI scans of that area of the brain. The researchers wanted to rule out placebo effects, so they also ran some tests with people who saw no brain imagery, or looked at someone else’s brain or a a different part of their own brain, and those people felt no improvement. I’m not sure what kind of treatment options might grow out of this work; access to an fMRI machine is not easy to come by. (I wonder if the people in ths study who practiced in the fMRI machine can reproduce the results without the machine once they’ve learned how it works.) But it can’t hurt to learn more about the brain systems involved in the perception of pain. I’ve always been a little skeptical about the degree to which changing your thoughts can make a physically painful situation any better (natural childbirth relaxation techniques didn’t help me much), but on the other hand, I didn’t have access to a picture of what my brain was doing or any experience in figuring out how to change that. So who knows.

http://mednews.stanford.edu/releases/2005/december/pain.html

Managing expectations

Psychology Comments Off

Sep 112005

“Managing expectations” is a buzz phrase in IT support and probably in other kinds of customer support as well. It looks like it also might be useful, with a different meaning, in the study of pain relief. Some recent research shows that how painful a stimulus feels is related not only to how intense the stimulus is, but how intense a person expects it to be. When people expected a less painful sensation and received a more painful stimulus, they perceived the sensation as less painful. Expecting a more painful feeling and getting a less painful one did not change the perception of the intensity. This is interesting not only for what new approaches it might suggest for pain relief, but also because it illustrates that the sensation of pain is a function of both the stimulus from damaged tissue or whatever and of the expectations we bring to it.

http://www.sciencenews.org/articles/20050910/fob5.asp

Garlic and pain

Psychology Comments Off

Aug 162005

The other day a friend offered me a sip of his drink. “What is it?” I wanted to know. He told me it contained compounds that evolved in plants to discourage herbivory. Ever the cautious type, I wanted more specific information about exactly what was in there. “Turpenes,” he said with relish. “And some quinine too.” I finally was able to extract from him the information that he was, in fact, drinking a gin and tonic. (I took a sip and didn’t like it.) It’s kind of funny that some herbivores (or omnivores) developed a taste for these compounds that arose in the first place because they tended to stop animals from eating the plants that contained them.

Here’s a story about how a sulfur-based compound in garlic causes reactions similar to those sparked by chili peppers and hot mustards, activating pain neurons and stimulating inflammation and blood vessel dilation. I’m guessing the compounds in garlic and chili peppers and wasabi may also have evolved in plants to discourage herbivory. Interestingly, garlic appears to trip only some of the neurons that react to hot peppers.

http://www.livescience.com/humanbiology/050816_ap_garlic_pain.html

Male and female responses to pain

Brain and mind, Male/female Comments Off

Jul 282005

This article from the Economist describes neurochemical differences in the way men and women perceive pain. Not only are women more sensitive to pain than men are, they respond differently to some painkillers. This is useful information for anyone who needs to prescribe (or take) analgesics. This article also contains some information about women’s different emotional responses to pain, and a little speculation about why the differences, neurochemical and emotional, might have arisen.

http://www.economist.com/science/displaystory.cfm?story_id=4197761

Using the brain’s own cannabinoids for pain relief

Brain and mind 1 Response »

Jun 232005

In light of the recent Supreme Court decision about the medical use of marijuana, this is an especially interesting press release about research into the brain’s own cannabinoids. Researchers have learned how to manipulate levels of a brain chemical that is active in relieving pain immediately after an injury. This work could lead to a pain-relieving pill that would work by increasing the action of this compound, thus sidestepping the legal issues surrounding marijuana use.

http://www.uga.edu/news/artman/publish/050622hohman.shtml

Feeling and observing pain

Thought and consciousness Comments Off

Jun 162005

This is an interesting little blurb about how the physical reactions to pain are the same whether you are observing the pain or experiencing it yourself. Volunteers who watched videos of a needle being stuck into someone else’s hand or foot were monitored for muscle activity in their hands and feet; the physical reactions were the same. Not sure what it means but it’s interesting.

http://www.newscientist.com/channel/being-human/mg18625035.500