Thursday, 30 May 2013

How does the brain react to a romantic breakup?

Image: JAMIE CARROLL iStockphot

Xiaomeng (Mona) Xu, a postdoctoral research fellow at the Warren Alpert Medical School at Brown University and at the Miriam Hospital, responds:
You're in the midst of a breakup and feel like a different person. You find yourself spending a lot of time longing for your ex, constantly checking her Facebook updates, and wondering what went wrong. This shift in patterns of thought and behavior may be caused by neural changes that occur after a breakup.
Neuroimaging studies have found that being rejected, even by a stranger, activates many of the same regions in the brain as when experiencing physical pain. In one study, biological anthropologist Helen Fisher of Rutgers University recruited brave participants who held still in a functional MRI scanner while they looked at pictures of the person who had recently dumped them. These participants exhibited increased brain activity in several regions associated with reward, motivation, addiction and obsessive-compulsive disorder, which helps to explain why you might struggle to let go after a romantic relationship ends.
Grief can also be a part of the breakup process. In another brain-scanning study, researchers asked women who had gone through a recent breakup to think about their ex in an fMRI machine. They found patterns of brain activity consistent with feelings of sadness, rumination and chronic depression.
For some people, heartache can continue months after a split. A team of German investigators, studying a small group of people who were still hung up on an ex up to six months after the relationship had ended, also found brain patterns consistent with depression, such as decreased activity in the insula and the anterior and posterior cingulate cortices.
Although such studies show that heartbreak is associated with obsession and grief, the findings are limited. Our understanding primarily comes from research in which participants are asked to actively think about their ex, something people probably don't do all the time. Additionally, studies tend to be about the heartbroken, rather than the heartbreakers, and focus only on the period of misery postsplit. Luckily for many people, the heartache from a lost relationship fades over time, and life goes back to normal. For some, the rupture might even become a positive experience, allowing a person to get away from a dysfunctional relationship and fall in love again.


You Are Less Beautiful Than You Think

beauty, self perception
Image: iStock/ Gruizza
In April 15, 2013 Dove launched a 3-minute video entitled “Dove Real Beauty Sketches.” The video achieved instant popularity and has been watched millions of times — a successful viral campaign which has been widely talked about. In the video, a small group of women are asked to describe their faces to a person whom they cannot see. The person is a forensic artist who is there to draw pictures of the women based on their verbal descriptions. A curtain separates the artist and the women, and they never see each other. Before all this, each woman is asked to socialize with a stranger, who later separately describes the woman to the forensic artist. In the end, the women are shown the two drawings, one based on their own description, the other based on the stranger’s description. Much to their amazement and delight, the women realize that the drawings based on strangers’ descriptions depict much more beautiful women. The video ends: “You are more beautiful than you think.”
The idea is quite appealing. Perhaps too many women are unhappy with their looks. It would be a big relief if we all suddenly realized, like Christian Andersen’s ugly duckling, that we are in fact beautiful.
However, what Dove is suggesting is not actually true. The evidence from psychological research suggests instead that we tend to think of our appearance in ways that are more flattering than are warranted. This seems to be part of a broader human tendency to see ourselves through rose colored glasses. Most of us think that we are better than we actually are — not just physically, but in every way.
The most direct evidence that the Dove commercial is misleading comes from the work of Nicholas Epley of the University of Chicago and Erin Whitchurch of the University of Virginia. In a series of studies, Epley and Whitchurch showed that we see ourselves as better looking than we actually are. The researchers took pictures of study participants and, using a computerized procedure, produced more attractive and less attractive versions of those pictures. Participants were told that they would be presented with a series of images including their original picture and images modified from that picture. They were then asked to identify the unmodified picture. They tended to select an attractively enhanced one.
Epley and Whitchurch showed that people display this bias for themselves but not for strangers. The same morphing procedure was applied to a picture of a stranger, whom the study participant met three weeks earlier during an unrelated study. Participants tended to select the unmodified picture of the stranger.
People tend to say that an attractively enhanced picture is their own, but Epley and Whitchurch wanted to be sure that people truly believe what they say. People recognize objects more quickly when those objects match their mental representations. Therefore, if people truly believe that an attractively enhanced picture is their own, they should recognize that picture more quickly, which is exactly what the researchers found.
Inflated perceptions of one’s physical appearance is a manifestation of a general phenomenon psychologists call “self-enhancement.” Researchers have shown that people overestimate the likelihood that they would engage in a desirable behavior, but are remarkably accurate when predicting the behavior of a stranger. For example, people overestimate the amount of money they would donate to charity while accurately predicting others’ donations. Similarly, people overestimate their likelihood to vote in an upcoming presidential election, while accurately predicting others’ likelihood to vote.
Most people believe that they are above average, a statistical impossibility. The above average effects, as they are called, are common. For example, 93 percent of drivers rate themselves as better than the median driver. Of college professors, 94 percent say that they do above-average work. People are unrealistically optimistic about their own health risks compared with those of other people. For example, people think that they are less susceptible to the flu than others. Stock pickers think the stocks they buy are more likely to end up winners than those of the average investor. If you think that self-enhancement biases exist in other people and they do not apply to you, you are not alone. Most people state that they are more likely than others to provide accurate self-assessments.
Why do we have positively enhanced self-views? The adaptive nature of self-enhancement might be the answer. Conveying the information that one has desirable characteristics is beneficial in a social environment. People may try to deceive others about their characteristics, but deception has two main disadvantages. First, it is cognitively taxing because the deceiver has to hold two conflicting representations of reality in mind: the true state of affairs and the deception. The resulting cognitive load reduces performance in other cognitive functions. Second, people are good at detecting deception and they show strong negative emotional reactions toward deceivers. Since in self-enhancement people truly believe that they have desirable characteristics, they can promote themselves without having to lie. Self-enhancement also boosts confidence. Researchers have shown that confidence plays a role in determining whom people choose as leaders and romantic partners. Confident people are believed more and their advice is more likely to be followed.


Age Brings Happiness

eldery asian lady, old lady, elderly lady, senior citizen
Image: ZHANG BO Getty Images
Do people get happier or crankier as they age? Stereotypes of crotchety neighbors aside, scientists have been trying to answer this question for decades, and the results have been conflicting. Now a study of several thousand Americans born between 1885 and 1980 reveals that well-being indeed increases with age—but overall happiness depends on when a person was born.
Previous studies that have compared older adults with the middle-aged and young have sometimes found that older adults are not as happy. But these studies could not discern whether their discontent was because of their age or because of their different life experience. The new study, published online January 24 in Psychological Science, teased out the answer by examining 30 years of data on thousands of Americans, including psychological measures of mood and well-being, reports of job and relationship success, and objective measures of health.
The researchers found, after controlling for variables such as health, wealth, gender, ethnicity and education, that well-being increases over everyone's lifetime. But people who have lived through extreme hardship, such as the Great Depression, start off much less happy than those who have had more comfortable lives. This finding helps to explain why past studies have found conflicting results—experience matters, and tough times can influence an entire generation's happiness for the rest of their lives. The good news is, no matter what we've lived through, we can all look forward to feeling more content as we age.


Scientists Discover Children’s Cells Living in Mothers’ Brains

pregnant woman
A living connection Image: ock / Анастасия Попова
The link between a mother and child is profound, and new research suggests a physical connection even deeper than anyone thought. The profound psychological and physical bonds shared by the mother and her child begin during gestation when the mother is everything for the developing fetus, supplying warmth and sustenance, while her heartbeat provides a soothing constant rhythm.
The physical connection between mother and fetus is provided by the placenta, an organ, built of cells from both the mother and fetus, which serves as a conduit for the exchange of nutrients, gasses, and wastes. Cells may migrate through the placenta between the mother and the fetus, taking up residence in many organs of the body including the lung, thyroid muscle, liver, heart, kidney and skin. These may have a broad range of impacts, from tissue repair and cancer prevention to sparking immune disorders.
It is remarkable that it is so common for cells from one individual to integrate into the tissues of another distinct person. We are accustomed to thinking of ourselves as singular autonomous individuals, and these foreign cells seem to belie that notion, and suggest that most people carry remnants of other individuals. As remarkable as this may be, stunning results from a new study show that cells from other individuals are also found in the brain. In this study, male cells were found in the brains of women and had been living there, in some cases, for several decades. What impact they may have had is now only a guess, but this study revealed that these cells were less common in the brains of women who had Alzheimer’s disease, suggesting they may be related to the health of the brain.
We all consider our bodies to be our own unique being, so the notion that we may harbor cells from other people in our bodies seems strange. Even stranger is the thought that, although we certainly consider our actions and decisions as originating in the activity of our own individual brains, cells from other individuals are living and functioning in that complex structure. However, the mixing of cells from genetically distinct individuals is not at all uncommon. This condition is called chimerism after the fire-breathing Chimera from Greek mythology, a creature that was part serpent part lion and part goat. Naturally occurring chimeras are far less ominous though, and include such creatures as the slime mold and corals.
 Microchimerism is the persistent presence of a few genetically distinct cells in an organism. This was first noticed in humans many years ago when cells containing the male “Y” chromosome were found circulating in the blood of women after pregnancy. Since these cells are genetically male, they could not have been the women’s own, but most likely came from their babies during gestation.
In this new study, scientists observed that microchimeric cells are not only found circulating in the blood, they are also embedded in the brain. They examined the brains of deceased women for the presence of cells containing the male “Y” chromosome. They found such cells in more than 60 percent of the brains and in multiple brain regions. Since Alzheimer’s disease is more common in women who have had multiple pregnancies, they suspected that the number of fetal cells would be greater in women with AD compared to those who had no evidence for neurological disease. The results were precisely the opposite: there were fewer fetal-derived cells in women with Alzheimer’s. The reasons are unclear.
Microchimerism most commonly results from the exchange of cells across the placenta during pregnancy, however there is also evidence that cells may be transferred from mother to infant through nursing. In addition to exchange between mother and fetus, there may be exchange of cells between twins in utero, and there is also the possibility that cells from an older sibling residing in the mother may find their way back across the placenta to a younger sibling during the latter’s gestation. Women may have microchimeric cells both from their mother as well as from their own pregnancies, and there is even evidence for competition between cells from grandmother and infant within the mother.
What it is that fetal microchimeric cells do in the mother’s body is unclear, although there are some intriguing possibilities. For example, fetal microchimeric cells are similar to stem cells in that they are able to become a variety of different tissues and may aid in tissue repair. One research group investigating this possibility followed the activity of fetal microchimeric cells in a mother rat after the maternal heart was injured: they discovered that the fetal cells migrated to the maternal heart and differentiated into heart cells helping to repair the damage. In animal studies, microchimeric cells were found in maternal brains where they became nerve cells, suggesting they might be functionally integrated in the brain. It is possible that the same may true of such cells in the human brain.
These microchimeric cells may also influence the immune system. A fetal microchimeric cell from a pregnancy is recognized by the mother’s immune system partly as belonging to the mother, since the fetus is genetically half identical to the mother, but partly foreign, due to the father’s genetic contribution. This may “prime” the immune system to be alert for cells that are similar to the self, but with some genetic differences. Cancer cells which arise due to genetic mutations are just such cells, and there are studies which suggest that microchimeric cells may stimulate the immune system to stem the growth of tumors. Many more microchimeric cells are found in the blood of healthy women compared to those with breast cancer, for example, suggesting that microchimeric cells can somehow prevent tumor formation. In other circumstances, the immune system turns against the self, causing significant damage. Microchimerism is more common in patients suffering from Multiple Sclerosis than in their healthy siblings, suggesting chimeric cells may have a detrimental role in this disease, perhaps by setting off an autoimmune attack.