Pain and Your Brain

Everyone is familiar with placebo effects.  Just taking a pill can reduce pain you are feeling, even if that pill has no active ingredients in it.  Indeed, placebo effects help even when you are taking an active ingredient.  I know that when I have a headache, taking some ibuprofen starts helping the pain fairly quickly, even though it can take up to 30 minutes for the medication to have an effect. 

It is hard to study pain and placebo effects, because pain is subjective.  That is, you can’t know whether people are experiencing pain unless you ask them.  If people want sympathy, they might exaggerate their report of pain.  If they want to avoid worrying their friends and relatives, they might minimize their report of pain. 

In addition, there may be many different psychological systems involved in pain, and different treatments might influence these systems in different ways.  But, people are only aware of the experience of pain.  So, just focusing on the pain people are feeling does not help researchers to tease apart the various ways that pain might be reduced.

An interesting paper by Tor Wager and Lauren Atlas in the January, 2013 issue of Perspectives on Psychological Science reviews evidence from brain imaging to tease apart the influences of placebos on pain.

In order to study placebo effects, it is important to know the regions of the brain that are involved in the sensation of pain.  Wager and Atlas first review studies in which participants were exposed to low-intensity and high-intensity heat in a functional Magnetic Resonance Imaging (fMRI) study.  The fMRI technique measures blood flow in the brain and gives researchers information about areas of the brain that are active in different situations. 

If you are interested in the specific brain areas associated with pain, check out original paper.   For now, what is important is that these brain areas provide a way for researchers to explore different effects of placebos. 

Researchers have suggested that placebo effects might reduce pain by activating opioid receptors in the brain.  Opioid receptors are the ones that opiate drugs (like morphine and codeine) activate.  The brain has natural chemicals that activate these receptors, and that helps minimize the experience of pain.  For example, research has shown that placebo effects are reduced by giving a person a chemical that blocks the activity of the opioid receptors.

One observation from these fMRI studies is that a region of the midbrain (see the figure for a sense of where the midbrain is located) is influenced by opioid receptors.  This area of the brain is affected by placebos.  In addition, areas of the frontal cortex of the brain (located in the brain above your eyes) is also related the strength of placebo effects. 

Here is where it gets interesting.  There are other areas of the frontal cortex that are involved in your ability to control your thinking.  Those areas of the brain are not involved in placebo effects. However, researchers also know that if you distract yourself, that can minimize the experience of pain.  Presumably, distraction involves these brain areas that are associated with thought control.

Based on these observations, other studies using brain imaging show that distraction does reduce pain, but it uses different brain regions than the areas involved in placebo effects.  As a result, these two techniques can be added together for a more powerful effect.  That is, a combination of a placebo and distraction is better than either one alone.

Finally, the pain-reducing opiate drugs involve some of the same brain mechanisms of placebo effects and distraction, but they involve some different ones as well.  Which means that in cases of the worst pain, a combination of all three effects can be more powerful than any one alone.

You might wonder how you get a placebo effect when you have taken a real drug.  Remember, though, that just the knowledge that you have been given a drug engages some pain relief.  That happens regardless of whether that drug is a real painkiller or something inert.  So, telling someone they are getting a pain drug and then giving them that pain drug creates both a placebo effect and the relief from the drug itself.

This work is interesting in two ways.  First, it provides some new insight into how placebo effects work.  Second, it shows how the maturing science of brain imaging can help science tease apart complex mechanisms that would be hard to study without insight into what the brain is doing.

Positive fantasies can reduce future effort

It is important to visualize what is going to happen in the future.  When you are making plans to accomplish a goal, it is valuable to think through all of the things that can go wrong.  That simulation of the future can help you to figure out what you are going to do to overcome the obstacles that may keep you from achieving your aims.

Sometimes when we think about the future, we focus on our eventual success as well.  We may think about how good it will feel to succeed and what rewards we might get from completing a difficult task.  What role do these positive fantasies play?

Research by Gabriele Oettingen and her colleagues has shown that thinking about the benefits of success can actually make you less likely to achieve your goals.  They can reduce the amount of effort that you want to put into achieving your aims.

A nice demonstration of this effect comes from a paper by Heather Kappes, Eesha Sharma and Gabriele Oettingen published in the January, 2013 issue of the Journal of Consumer Psychology.

In one study, participants read about a charity that was addressing a health crisis in Sierra Leone.  Many people in that country do not have access to pain medications that they need.  College students read an article about this crisis and then were told about a charity that was helping to bring pain medications to this country.  Some participants were asked to form a positive fantasy by thinking about the most positive thing that would happen if that crisis was resolved.  Other participants were asked to give a factual description of the crisis after it was resolved.

Afterward, participants were asked to donate money to the charity.  They were either asked to give a small donation ($1) or a large donation ($25, which is a lot of money for the typical undergraduate). 

Participants who were asked to give $1 were quite likely to donate regardless of the condition they were in, and those who were encouraged to think positively were actually somewhat more likely to give than those who were not.  Participants who were asked to give $25 were much less likely to give overall.  In this case, though, participants who thought positively almost never donated, while about 25% of those who gave a factual description were willing to donate. 

Another study found a similar effect with participants who were asked to volunteer their time to a cause rather than donating money.  In this study, participants who engaged in a positive fantasy were unlikely to give their time when they were asked for a lot of effort compared to those who were asked to think factually about a charity. 

A third study demonstrated that this effect was a result of thinking positively and not an effect of the factual description in the control group.  In this study, the control group did a boring task for a few minutes rather than giving a factual description.  Once again, people asked to volunteer a lot of time were unwilling to do it if they had created a positive fantasy, but if they did a boring task for a few minutes, they were more willing to volunteer a lot of time to help a charity.

These studies are a nice demonstration of the potential danger of positive fantasies.  If we spend a lot of time envisioning our success, we may begin to feel some of the satisfaction that comes with actually achieving a goal.  It is hard to motivate yourself to work hard to succeed when you are already feeling some of the rewards of that success.

Ultimately, it is better to focus on the difficulties that lie ahead when faced with a difficult task.  It may not be pleasant to think about the problems you will face, but it will make you more likely to get past those barriers.

The pain of positive stereotypes

When we think of the problems that stereotypes cause, we typically focus on negative characteristics associated with groups.  Over the years, I have been part of conversations where someone uses the term “Jew” to refer to someone who is being cheap.  I leave those interactions frustrated and angry.

Presumably, though, there are positive stereotypes as well.  In the United States, there are cultural stereotypes that Asians are good at math and that Women are nurturing.  If hearing a negative stereotype about your group gets you upset, does hearing a positive stereotype have the opposite effect?

This question was explored in a series of studies by John Oliver Siy and Sapna Cheryan in the January, 2013 issue of the Journal of Personality and Social Psychology. 

In one study, Asian Americans were brought to the lab where they engaged in a task along with a White participant (who was actually one of the experimenters posing as a participant).  In the experiment, each participant was going to fill out a packet.  One packet had math problems in it, while the other had verbal problems in it.  After a rigged coin flip to make the selection process appear random, the White participant was chosen to select who would fill out each packet.

In the control condition, the White participant handed the math packet to the Asian participant and said, “How about you take this packet, and I’ll work on this one.”  In the positive stereotype condition, the White participant said, “I know all Asians are good at math, how about you take the math packet.  I’ll work on this one.”

After completing the packets, participants rated how much they liked their partner and they filled out some other scales including a measure of how much they felt like their partner depersonalized them by reducing them to a member of their racial group. 

Positive stereotypes did not make people feel good.  When the White participant used a positive stereotype, the Asian participant liked them less and felt more depersonalized.  The positive stereotype also made the participants angry.  Statistically, the amount of depersonalization they felt explained the amount of dislike they felt for their partner.

Other studies in this series demonstrated a similar effect with women who were told that they were nurturing or cooperative because of their gender.  These studies also ruled out some other explanations like the possibility that Asian Americans react negatively to the positive stereotype because it does not acknowledge that they are both Asians and Americans.

Across all of the studies done in this paper, a positive stereotype made people feel less like an individual.  Under some circumstances, though, this did not cause people to dislike the person who used the stereotype.  In one study, Asian American participants were primed to think of themselves either in independent or interdependent terms.  The independent prime asked people to think about ways that they were different from family and friends.  The interdependent prime asked people to think about ways that they were similar to family and friends. 

After this priming, participants were exposed either to a positive stereotype (in this case that Asians are hard working) or to no stereotype. Participants rated how much they liked the speaker as well as whether they felt depersonalized.  As in the other studies, hearing a positive stereotype led to greater feelings of being depersonalized for everyone in the study.  However, only the people with primed to think of themselves in independent terms strongly disliked the speaker.  Those primed to think of themselves in interdependent terms did not dislike the speaker significantly more after hearing a positive stereotype compared to no stereotype.

What is going on here?

Stereotypes of all kinds lump an individual into a group.  When you find a stereotype applied to you, it removes some of your individuality.  That happens whether the stereotype used was positive or negative.  It is frustrating to realize that someone views you just as a member of a group and not as an individual.  And in many situations, that leads you to dislike the person who made the comment.

It is fascinating, though, that when you feel more interconnected with others (as you do when you are primed to think of yourself in interdependent terms), the depersonalization caused by hearing a stereotype aimed at you does not lead to the same dislike of the speaker. 

Finally, I suspect there is an additional factor at play in these studies.  When someone uses a positive stereotype to judge you, it is reasonable to assume that it is only a matter of time until they apply negative stereotypes as well.  That is, you are making a judgment that the person you are talking to uses stereotypes to make judgments.

The studies in this series did find that depersonalization explained the negative effects of positive stereotypes above-and-beyond the judgment that the speaker was racist.  But, the judgment that the speaker was racist (and used stereotypes to judge people) also contributed to the effects.

Do you prefer more choice or less? It depends on distance.

The appeal of big box retailers has always been a mystery to me.  On those rare occasions when I have to go to a place like Bed, Bath, and Beyond, I often find it frustrating.  Not long ago, I had to get a new coffee maker, and I fought through the crowd in the parking lot into the store.  From there, I stood before the wall of coffee makers, struggling to decide which of the huge number of options would be best.  There were so many choices, that I am not at all sure that I got the best one.

So, why are these stores so crowded?

There is an interesting tradeoff at work here.  On the one hand, people want to have lots of options.  That gives them the feeling that their choice is not at all constrained.  On the other hand, as the number of options goes up, the choice gets more difficult to make, and that can make it hard to know whether you have made a good decision.

An interesting paper in the December, 2012 issue of the Journal of Consumer Research by Joseph Goodman and Selin Malkoc examined how people resolve this tradeoff.  They find that preferences for the size of a set of options depends on the distance to the choice.

Lots of work, starting with studies by Yaacov Trope and Nira Liberman have explored influences of distance on thinking.  This work suggests that as an event gets nearer in space or time, people think about it more specifically. When that event gets further in space or time, people think about it more abstractly. 

In the case of choices, thinking more specifically has two effects.  On the one hand, when you think about a choice specifically, each of the options feels distinct.  The individual properties of a set of coffee makers, for example, becomes important.  So, thinking specifically can make you want a larger set of options.  When you think about the choice abstractly, all of the options seem more similar, and so the size of the set of options becomes less important. 

However, thinking specifically can also make it clear how hard it is to choose from among a large set of options.  This choice difficulty is less prominent when thinking abstractly.

The researchers found that distance can have both influences on the way people evaluate sets of options.

In most normal cases, people are not that focused on how hard it will be to make a choice.  In those situations, decreasing distance to a choice makes people think about the options as distinct.

In one study, college students were told about two restaurants that were opening.  They were going to be offered a gift certificate good for a free entrée on the day the restaurant opened.  They had to pick which restaurant they wanted to try.  Participants saw the menus for each restaurant.  One restaurant had many options (14), while the other had only a few (7). Some participants were told that the restaurant was opening that day (near in time), while other participants were told the restaurant was opening in five months (far in time). 

When participants were making the choice for a restaurant opening that day, they picked the restaurant with the larger selection 63% of the time.  When they were selecting a restaurant that was opening in five months, they picked the one with the larger assortment only 46% of the time.

In another study, participants were told to imagine that they were planning a dinner party for friends that was taking place the next day or several months later.  They discovered that their blender had broken and they needed a new one before the party.  In this case, they had a choice between two stores, one of which had a larger assortment (18 blenders) than the other (6 blenders).  People saw descriptions of the blenders, which were designed to be of about the same quality.  Participants were also asked to look over the set and to rate how similar they thought the set of blenders was. 

As in the previous study, participants were more likely to select the store with the larger assortment when they were going shopping that day than when they were going shopping in several months.  In addition, people perceived the entire set of blenders to be less similar when they were going shopping that day than when they were going shopping in several months.  This combination of results shows that people see the items as more unique when they are near in time to the event than when they are far from it.

Another study in this series examined the case where people were also focused on the difficulty of making a choice.  This study was similar to the one I just described except that some people were also told that evaluating each blender in the store would take between 3 and 5 minutes.  That information made it clear that evaluating a larger assortment would take much more time than evaluating a smaller one. 

In this study, participants who were not focused on the difficulty of making a choice showed the same pattern as the previous studies.  They preferred the store with the larger assortment when they were making the choice that day than when they were making it in several months.  When people were focused on the difficulty of making a choice, though, the pattern flipped.  Now, they were more interested in the store with the smaller assortment when they were making the choice immediately and the store with the larger assortment when making the choice in several months.

Ultimately, both factors should play some role when making a choice.  In cases where it is critical that you find an option that perfectly fits your needs, it is good to have a large assortment (as long as you have the time and ability to evaluate all of the items).  Most of the time, though, you probably need something that is just good enough.  In those cases, it might be better to find a store with a smaller number of high-quality options. 

Finally, remember that you will think differently about the value of having many options depending on how far away the choice is from you. Take that into account when deciding where to shop.