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The so-called “love hormone” oxytocin, which is linked to a mother’s tender feelings for her child and long-term devotion between mates, may play a more general role in promoting the social cohesion of a group. In a small new study, researchers found that volunteers who got an oxytocin boost were better able to recognize faces they had seen the day before than people who got a placebo, but were no better at recognizing landscapes and and sculptures that they’d previously viewed.

The results are “striking,” says psychologist Thomas Insel, director of the National Institute of Mental Health in Bethesda, Maryland. Insel and colleagues have [previously] shown that oxytocin improves the ability of mice to recognize other mice, … but he notes that this is the first time such a specific effect has been seen in humans. The research “supports the notion that social memory is a unique form of memory, biologically distinct from general object memory,” he says [ScienceNOW Daily News].

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Playing the absorbing video game Tetris immediately after a traumatic experience could reduce the most jarring symptom of post-traumatic stress disorder (PTSD), the flashbacks in which the distressing memory invades the brain. In an odd new study, researchers showed volunteers ugly images of nasty accidents, crushed-up skulls and bloody entrails from various sources. Then they asked half of them to play Tetris. While the other half apparently did nothing…. The Tetris players apparently suffered significantly fewer nasty memories of those ugly images than did those who were left idle [CNET].

The Tetris players may have experienced fewer flashbacks because they were distracted during a crucial window of opportunity, the few hours after the traumatic incident when the brain is consolidating the memory. Says lead author Emily Holmes: “We wanted to find a way to dampen down flashbacks - the raw sensory images of trauma that are over-represented in the memories of those with PTSD. Tetris may work by competing for the brain’s resources for sensory information. We suggest it specifically interferes with the way sensory memories are laid down in the period after trauma and thus reduces the number of flashbacks that are experienced afterwards” [BBC News]. Playing Tetris could be considered a “cognitive vaccine” against flashbacks, Holmes suggested.

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The facial expressions that register human joy and disappointment may be hard-wired into our brains, according to a new study. To probe the origins of smiles and scowls, psychologist David Matsumoto and his team compared 4,800 photographs, capturing the expressions of sighted and blind judo athletes at medal ceremonies at the 2004 Olympic and Paralympic Games. In each case, the faces of gold and silver medal winning athletes were scrutinised [BBC News].

The researchers found that both the blind and sighted gold medal winners produced joyful smiles known as Duchenne smiles, in which the cheek muscles rise and the muscles around the eyes crease. In contrast, both blind and sighted silver medal winners initially showed sadness, with their mouths turned down, but put on “social smiles” that use only the mouth muscles when they received their medals.

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In a new study, most people willingly pulled a lever to deliver pain to others when instructed to do so, showing that little has changed in the near half-century since psychologist Stanley Milgram’s famous electric shock experiment. Milgram’s experiment revealed our propensity to do harm when encouraged by authority, a topic of great interest in the post-World War II years. A new iteration of the experiment (with added precautions) revealed that seven out of ten people will give painful electric shocks to another person as part of what they are told is a scientific investigation. “What we found is validation of the same argument—if you put people into certain situations, they will act in surprising, and maybe often even disturbing, ways,” [Reuters] says researcher Jerry Burger.

In the 1961 experiment, Yale University professor Milgram asked volunteers to deliver increasingly strong electric “shocks” to other people, who appeared to be test subjects but were really actors, if they answered certain questions incorrectly. Milgram found that, after hearing an actor cry out in pain at 150 volts, 82.5 percent of participants continued administering shocks, most to the maximum 450 volts [Reuters]. The results, now a fixture in psychology textbooks, suggested that people’s moral attitudes can be suppressed when they’re put in a situation of obedience. Although no actual shocks were delivered and the sounds of agony came from a tape-recording, many of the volunteers suffered stress from the task and replication of the experiments was deemed unethical.

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When a juror first makes a decision on the guilt of a defendant and then hands down a sentence, two entirely different regions of the brain are involved, a new brain imaging study has shown—and neither is as rational as we might want to believe. Researchers using functional MRI scans found that a brain in the process of making a decision about the guilt of another person looks a lot like the brain of a person deciding whether they themselves have been wronged; what’s more, decisions about punishment are linked to brain regions that process emotions. “Our judicial system based on third-party punishment is usually seen as cold and detached as opposed to … punishment by the victim of a crime,” [study coauthor René] Marois says. The new study shows that emotions play a part in impartial judgment too [Science News].

Judgments of the culpability of another person were linked to activity in the right dorsolateral prefrontal cortexes, researchers found; this region has previously been implicated in decisions of morality and fairness, as well as other functions unrelated to the law. When another team temporarily blocked [activity in this region] with a magnet, participants playing a financial game that tests trust failed to punish unfair offers. No-one expected that almost the same cognitive machinery kicks in when impartially making a decision about cheating and when you yourself are cheated [New Scientist], says study coauthor Owen Jones.

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Dogs have a sense of fairness, and get jealous and upset when several dogs perform a trick but only one is rewarded, a new study has found. “They are clearly unhappy with the unfair situation”, says [lead researcher Friederike] Range. She also suspects that this sensitivity might stretch beyond food to things like praise and attention. “It might explain why some dogs react with ‘new baby envy’ when their owners have a child”, she says [New Scientist].

While some owners may say that they’ve known about the deep emotional lives of their dogs for ages, the new experiments mark the first time a complicated emotion like jealousy has been observed in dogs in a controlled laboratory setting. “We are learning that dogs, horses, and perhaps many other species are far more emotionally complex than we ever realized,” [says] Paul Morris, a psychologist at the University of Portsmouth who studies animal emotions…. “They can suffer simple forms of many emotions we once thought only primates could experience” [Times Online].

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Happiness is catching and spreads like the flu, according to a study that followed a whole community of people for 20 years. The effect of one happy person could ripple through three degrees of separation, researchers report. “It is sometimes said that you can’t be happier than your least happy child. It is truly amazing to discover that when you replace the word ‘child’ with ‘best friend’s neighbor’s uncle,’ the sentence is still true,” [Boston Globe] said psychologist Daniel Gilbert, who was not involved in the study. The researchers liken the pattern of happiness transmission to the spread of a virus: those with the most number of happy contacts are the mostly likely to catch the happy bug.

The study, published in the British Medical Journal, followed more than 4,700 people living in Framingham, Massachusetts from 1983 to 2003. The participants answered periodic questionnaires about their emotional well-being and listed the names of relatives, friends, and co-workers, many of whom were also participating in the study. Researchers found that happiness wasn’t scattered evenly throughout the population but instead seemed to spread through social networks. “Happiness is like a stampede,” said [co-author] Nicholas Christakis… “Whether you’re happy depends not just on your own actions and behaviors and thoughts, but on those of people you don’t even know” [AP].

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It’s no fun being bullied, but new research supports what many teenagers have long suspected: A victim’s pain may be a bully’s gain. A new brain imaging study of aggressive teenage boys found that watching others being bullied triggered parts of their brains associated with pleasure. “It is entirely possible their brains are lighting in the way they are because they experience seeing pain in others as exciting and fun and pleasurable,”[Reuters] said co-author Dr. Benjamin Lahey.

The study subjects were 16 boys 16 to 18 years old, half of whom had aggressive conduct disorder and half of whom had no behavioral disorder. While their brains were hooked up to functional MRIs, the boys were shown video clips of people getting hurt either by accident, such as having a heavy object dropped on their hands, or by intentional actions by others, such as someone stomping on their feet. Lahey said he expected an emotionally indifferent response to pain from subjects with conduct disorder, a mental disorder characterized by aggressive, destructive or harmful behavior towards other people and animals and can include theft, substance abuse and sexual promiscuity, according to the American Academy of Child and Adolescent Psychiatry. Instead, fMRI scans showed a strong but highly atypical emotional response [ABC News].

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Volunteers who held a warm cup of coffee in their hands were more likely to rate other people as warm, generous, and sociable, a new study has found, in contrast to those subjects who cradled a cup of ice coffee. In a second experiment, people who held a heating pad were more likely to give a small reward to a friend than keep it for themselves, in contrast to those who held an icepack. In other words, researchers concluded, holding something warm makes you feel more generous toward others; holding something cold makes you, well, cold and selfish [Scientific American].

The findings offer a neat reversal of another recent study, which also studied the phenomenon of the unconscious “priming” of thoughts; in that earlier study, volunteers who experienced social rejection were found to prefer a hot beverage to a cold one, presumably as a way to restore their good spirits. The message of both studies is that very subtle cues from our environment can significantly influence behavior and feelings, said lead researcher Dr. Lawrence Williams…. Physical and psychological concepts “are much more closely aligned in the mind than we have previously appreciated,” said Williams [AP].

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In a counterintuitive new study, researchers have found that obese women get less pleasure from drinking a chocolate milkshake than average-weight women, and suggest that obese women are therefore more likely to overeat in an attempt to get that high. Researchers used a fMRI brain scanner to record women’s levels of the pleasure-providing brain chemical dopamine while they were sipping milkshakes, and found that obese women had a muted pleasure response.

They also studied a dopamine-regulating gene variant that has previously been linked to obesity, and showed that women with this variant had the lowest dopamine levels and were also very likely to gain weight over the ensuing year. Dopamine expert Nora Volkow says this furthers the research on the genetic component of obesity: “It takes the gene associated with greater vulnerability for obesity and asks the question why. What is it doing to the way the brain is functioning that would make a person more vulnerable to compulsively eat food and become obese?” [AP]

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People who feel that they lack control while participating in lab experiments are more likely to see patterns where none exist, researchers say, in a finding that helps explain persistent beliefs in superstitions and conspiracy theories. In a new study, researchers manipulated volunteers’ perception of control and then watched the insecure subjects find connections where none existed in an apparent attempt to restore a sense of order to the world.

In one experiment, researchers gave half the volunteers a feeling of powerlessness and confusion by randomly scoring them right and wrong (and mostly wrong) on a series of questions. Then the volunteers had to find patterns. In one task, they were asked to find faint images in grainy patterns of dots. Half of the pictures had images and the others were random dots. While people in both groups correctly spotted the images, the group that felt they lacked control from a previous part of the experiment also “saw” images in 43 percent of pictures that were not there [Reuters].

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Teenage boys with behavior problems may be able to blame their brain chemistry, according to a new study. Psychologists studied boys with a history of antisocial behavior and measured their levels of the hormone cortisol, which usually surges during stressful situations, causing people to focus and behave more cautiously. They found that the troubled boys didn’t have the normal cortisol spike when they were put under stress, suggesting that they weren’t getting a chemical signal to regulate their emotions and actions.

Researchers say the findings suggest that some bad behavior should be considered a form of mental illness. “Most research has looked at social factors like peer groups, family life and socioeconomic factors,” said [lead researcher] Graeme Fairchild…. “These findings basically indicate that antisocial behavior is probably more biologically based than many people recognize and is similar to conditions like depression and anxiety” [Reuters].

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Ever wondered what causes the spate of wild bidding in the last few minutes of an Ebay auction? Scientists say they now have answer: The irrational behavior is caused by people’s fear of losing, not their desire to win. While economists have recognized the concept of “loss aversion” for some time, a new set of experiments used brain scans and lab experiments to show how strongly the phenomenon plays out in auctions, and how it’s tied to overbidding.

In the first experiment, test subjects participated in either a lottery or an auction. During the games, scientists watched the responses of the subjects’ striata—the brain’s reward center—using functional magnetic resonance imaging (fMRI). The elation of winning was the same in both games, but the agony of defeat was crushing for losers of the auction. After auction, brain activity in the loser’s reward centers decreased substantially. But it hardly blipped when the person lost a lottery [Ars Technica]. What’s more, auction losers who had the steepest declines in striata activity were more likely to have overbid during the auction.

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A new psychological study has found that social exclusion made test subjects feel literally cold, and increased their preference for warm beverages and soup. It’s the latest finding from the field of embodied cognition, in which researchers have shown that the language of metaphor can activate physical sensations, and vice versa…. “We know that being excluded is psychologically painful,” said the lead author, Chen-Bo Zhong… “and here we found that it feels just like it’s described in metaphors,” like icy stare and frosty reception [The New York Times].

Researchers conducted two experiments in the study, which was published in the journal Psychological Science [article not yet online]. In the first, they divided 65 students into two groups. They asked the first group to recall a time when others left them out. The second group recalled a time when they were included by others. In the middle of this, purportedly in response to maintenance staff, they were asked to estimate the temperature of the room [WebMD]. They found that the students who had been remembering an emotionally painful moment of rejection estimated that the room was much colder than the other students.

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The debate over the roots of homosexuality is possibly the most contentious manifestation of the “nature versus nurture” argument; gay rights advocates, gay rights opponents, and scientists have all joined the fray, advancing and criticizing different theories. With a new brain imaging study, the “nature” proponents seem to have gained a point in their favor.

Swedish researchers did MRI scans of 50 heterosexual men and women and 40 homosexual men and women and found surprising parallels. The brains of lesbians and straight men were anatomically symmetrical while the brains of gay men and straight women had a larger right brain hemisphere.

The researchers also looked at the amygdala, a part of the brain that’s associated with emotions, and found that straight women and gay men both have more connections between the amygdala and brain regions associated with anxiety and mood disorders. Meanwhile, the amygdala of lesbians and straight men had more connections to the region that controls fight or flight reactions.

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