Thursday, July 22, 2010

READING THE LOOK OF LOVE

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How fast you can judge whether a person of the opposite sex is looking at you depends on how masculine or feminine they look, according to a new study. The researchers speculate that there may be an evolutionary advantage to quickly noticing when a hottie is looking at you.

Psychologists have debated how we determine whether someone else is looking at us or not. One point of view is that "it's almost a geometric problem," says Benedict C. Jones, of the University of Aberdeen in Scotland – that people just look at the whites of the eyes and other features of the face, without being influenced by the face in general. But Jones and his colleagues, Julie Main, Lisa DeBruine, and Lisa Welling of the University of Aberdeen and Anthony Little of Stirling University, thought there was more to it. They designed an experiment to see whether how masculine or feminine the face was affected how quickly a viewer could assess its gaze.

Volunteers looked at faces with exaggerated or reduced male or female features; the faces had been morphed to look either more or less masculine or feminine. As the faces flashed on a computer screen, the volunteer was supposed to hit a key as quickly as possible to indicate whether the face was looking at them or away from them. Both women and men could do that more quickly when the face had exaggerated sexual characteristics. "Women were quickest to classify gaze direction when they were looking at hunky, masculine-looking guys. Guys were quicker when they were looking at pretty, feminine women," says Jones. The research is published in Psychological Science, a journal of the Association for Psychological Science.

Jones speculates that this ability to perceive things about attractive people faster may have been useful to early humans. Previous research shows that feminine women and masculine men make the healthiest mates. "There's likely to be quite a big advantage to detecting when a particularly good potential mate's looking at you," says Jones. "If I'm in a bar and there's a pretty woman looking at me – if I wasn't married – I would want to catch her eye before someone else did."

Psychological Science

IS YOUR LEFT HAND MORE MOTIVATED THAN YOUR RIGHT HAND?

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Motivation doesn't have to be conscious; your brain can decide how much it wants something without input from your conscious mind. Now a new study shows that both halves of your brain don't even have to agree. Motivation can happen in one side of the brain at a time.

Psychologists used to think that motivation was a conscious process. You know you want something, so you try to get it. But a few years ago, Mathias Pessiglione, of the Brain & Spine Institute in Paris, and his colleagues showed that motivation could be subconscious; when people saw subliminal pictures of a reward, even if they didn't know what they'd seen, they would try harder for a bigger reward. In the earlier study, volunteers were shown pictures of either a one-euro coin or a one-cent coin for a tiny fraction of a second. Then they were told to squeeze a pressure-sensing handgrip; the harder they squeezed it, the more of the coin they would get. The image was subliminal, so volunteers didn't know how big a coin they were squeezing for, but they would still squeeze harder for one euro than one cent. That result showed that motivation didn't have to be conscious.

For the new study, in Psychological Science, a journal of the Association for Psychological Science, Pessiglione and his colleagues Liane Schmidt, Stefano Palminteri, and Gilles Lafargue wanted to know if they could dig even farther down and show that one side of the brain could be motivated at a time. The test started with having the subject focus on a cross in the middle of the computer screen. Then the motivational coin – one euro or one cent – was shown on one side of the visual field. People were only subliminally motivated when the coin appeared on the same side of the visual field as the squeezing hand. For example, if the coin was on the right and they were squeezing with the right hand, they would squeeze harder for a euro than for a cent. But if the subliminal coin appeared on the left and they were squeezing on the right, they wouldn't squeeze any harder for a euro.

The research shows that it's possible for only one side of the brain, and thus one side of the body, to be motivated at a time, says Pessiglione. "It changes the conception we have about motivation. It's a weird idea, that your left hand, for instance, could be more motivated than your right hand." He says this basic research helps scientists understand how the two sides of the brain get along to drive our behavior.

Psychological Science

STUDY FINDS ROMANTIC REJECTION STIMULATES AREAS OF BRAIN INVOLVED IN MOTIVATION, REWARD AND ADDICTION

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The pain and anguish of rejection by a romantic partner may be the result of activity in parts of the brain associated with motivation, reward and addiction cravings, according to a study published in the July issue of the Journal of Neurophysiology (http://jn.physiology.org/).

The study’s findings could have implications for understanding why feelings related to romantic rejection can be hard to control, and may provide insight into extreme behaviors associated with rejection, such as stalking, homicide and suicide—behaviors that occur across many cultures throughout the world.

In the study, researchers used functional magnetic resonance imaging (fMRI) to record brain activity in 15 college-age, heterosexual men and women who had recently been rejected by their partners but reported that they were still intensely “in love.” The average length of time since the initial rejection and the participants’ enrollment in the study was 63 days, and all participants scored high on a psychological test called the Passionate Love Scale, which determines the intensity of romantic feelings. All participants said they spent more than 85% of their waking hours thinking of the person who rejected them, they yearned for the person to return and they wanted to get back together.

Participants each viewed a photograph their former partners. Then they completed a simple math exercise, such as counting backwards from a random four-digit number by 7, to distract them from their romantic thoughts. Finally, they viewed a photograph of a familiar “neutral” person, such as a roommate’s friend.

The researchers found that looking at photographs of the participants’ former partners stimulated several key areas of the participants’ brains more than looking at photos of neutral persons did. The areas are:

*the ventral tegmental area in the mid-brain, which controls motivation and reward and is known to be involved in feelings of romantic love,
*the nucleus accumbens and orbitofrontal/prefrontal cortex, which are associated with craving and addiction, specifically the dopaminergic reward system evident in cocaine addiction, and
*the insular cortex and the anterior cingulate, which are associated with physical pain and distress.

The researchers note that their findings supply evidence that “the passion of ‘romantic love’ is a goal-oriented motivation state rather than a specific emotion” and that their results are “consistent with the hypothesis that romantic rejection is a specific form of addiction.” Those who are coping with a romantic rejection may be fighting against a strong survival system that appears to be the basis of many addictions. The data help to explain why the beloved is so difficult to give up.

There is hope for the lovelorn, however: The researchers found that the greater the number of days since the rejection, the less activity there was in the area of the brain associated with attachment, the right ventral putamen/pallidum area, when the participants viewed photographs of their former partners. Also, areas associated with reappraising difficult emotional situations and assessing one's gains and losses were activated, suggesting that rejected individuals are trying to understand and learn from their difficult situation--what could be an adaptive response to rejection. If attachment responses decrease as the days go by and falling out of love is a learning process, there could very well be physiological evidence that time heals all wounds.

The American Psychological Society

SURPRISING FIND MAY YIELD NEW AVENUE OF TREATMENT FOR PAINFUL HERNIATED DISCS

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An immune cell known to cause chronic inflammation in autoimmune disorders has been identified as a possible culprit in low back pain associated with herniated discs, according to doctors at Duke University Medical Center.

The finding implicates the cytokine molecule interleukin-17, and supports the burgeoning theory that an immune response plays a significant role in disc disease, says William J. Richardson, MD, an orthopedic surgeon at Duke. It may also open the door for new, therapeutic approaches that target a specific immune response in hopes of halting disc destruction, and possibly reversing the disease process.

“By identifying the specific subpopulation of lymphocytes (immune cells that are excited into action by the cytokine), it may soon be possible to arrest the body’s inflammatory response to disc cells,” says Richardson, senior author of the research published online this week in the July issue of Arthritis and Rheumatism. Doing so could reduce the painful inflammation associated with degenerative disc disease, and halt the evolution of arthritis. It may also reduce the need for back surgery.

“Mechanical forces may initiate the degenerative process, but biochemical inflammatory changes certainly play a role in disc pathology,” says the study’s first author, Mohammed Shamji, MD, PhD, senior neurosurgery resident at The Ottawa Hospital, Ontario, Canada, who participated in the research while at Duke. Decreasing the inflammation may arrest or reverse the patient’s disease process and perhaps reduce the need for surgery. “Now we are learning which pathways we have to block.”

Low back pain is one of the most common reasons people seek medical care, and both degenerative and herniated discs -- also referred to as slipped discs or ruptured discs -- are common causes of that pain. The economic impact of medical care for herniated discs in the U.S. is estimated to be as high as $200 billion per year.

Herniated discs occur when the tough outer layer of cartilage cracks, allowing pieces of the softer inner material to protrude into the spinal canal. Until recently, it was thought that pain occurs when the material touches a nerve. Now doctors believe the pain is the result of an immune response caused by the presence of inflammatory cells.

“The center of the disc is immune-privileged since it has never been exposed to the immune system,” says Shamji. When a disc is injured or degenerates, the body reacts against the invading inner material as it would against any virus or foreign body, and launches a response targeted at destruction. The nerve root, which is present near the protruding disc material, becomes painfully inflamed, swollen and damaged during that cascade of events.

In recent years, several anti-immune therapies, including steroids, have been injected into the space between the disc and the nerve, but with limited success, doctors say, because they don’t target a specific immune response, and because low doses are used to minimize potentially serious side effects that include a higher predisposition to infection, activation of tuberculosis and a six-fold increase in lymphoma incidence.

The identification of IL-17 in the cascade of events is significant, Shamji says. “It’s a product of a specific subgroup of immune cells that are involved in auto immune phenomena like rheumatoid arthritis and asthma, but not in the body’s response against infection or tumor. If you target this specific lymphocyte, you may avoid compromising the body’s ability to protect itself against infection or tumor.”

Researchers say they’re still several steps away from human studies of IL-17 blockers currently in development.

Duke University Medical Center

COLUMBIA RESEARCHERS SHED LIGHT ON BIRTH OF THE FIRST STARS

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In the beginning, there were hydrogen and helium. Created in the first three minutes after the Big Bang, these elements gave rise to all other elements in the universe. The factories that made this possible were stars. Through nuclear fusion, stars generated elements such as carbon, oxygen, magnesium, silicon and the other raw materials necessary for making planets and ultimately life.

But how did the first stars come to be? New research from Columbia University shows that it all boils down to this simple reaction:

H- + H → H2 + electron

“In order for us to follow the chain of events responsible for how we got here, we need to understand the beginning,” said Daniel Wolf Savin, a senior research scientist in Columbia University’s Astrophysics Laboratory. The work of Savin and his collaborators, who include lead author and former group member Holger Kreckel, now at the University of Illinois, was published July 2 in the journal Science.

Savin’s research details a key chemical reaction that took place in the universe about a million years after the Big Bang. That reaction, called associative detachment, allowed clouds in the universe to cool, condense and form the first stars.

“In order to understand how the first stars formed, we need to know how the clouds that gave birth to them cooled. Molecular hydrogen (H2) radiated the heat out of the clouds, so we need to know how much H2 was in the cloud. This in turn requires understanding the chemical process by which the H2 formed. That’s what we’ve measured,” said Savin.

H2 is formed when two hydrogen atoms come together and bind to one another to make a molecule. Savin’s group measured this probability. His results show that the likelihood for this is higher than previous theoretical calculations and experiments have shown.

“The previous uncertainty in this reaction limited our ability to predict if a cloud of gas would form a star or not, and if it did, then what the mass of that star would be,” said Savin. “That’s an important thing to quantify, because the mass of a star determines the elements it will synthesize.”

The predicted masses for the first stars depend on the initial conditions of the primordial clouds from which they formed. These conditions are highly uncertain and still an active area of research. By comparing model predictions to observations of the universe astronomers can approximate what these initial conditions must have been. But the accuracy of these estimates depends critically on our understanding of the underlying chemical reactions, particularly those measured by Savin and his group. With the new data in hand, cosmologists will be better able to determine what the initial conditions were in the early universe leading to the formation of the first stars.

(Photo: Ralf Kaehler and Tom Abel)

Columbia University

GIANT SPERM WHALE FROM THE MIOCENE PERIOD DISCOVERED IN PERU

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The sperm whale fossil record had still not revealed all its secrets – until now! With the exception of a few isolated, large teeth, only animals significantly smaller than modern sperm whales have been discovered. In November 2008, during excavations organised by an international team (Muséum National d'Histoire Naturelle / Centre National de la Recherche Scientifique (CNRS); Museo de Historia Natural, Lima; Università di Pisa, Pisa; Natuurhistorisch Museum, Rotterdam; Muséum des Sciences Naturelles, Bruxelles) in the coastal desert of the Ica region (southern Peru), the remains of a very large fossil sperm whale were unearthed in Miocene beds (12-13 million years ago) at the Cerro Colorado site. The skull, lower jaw and teeth of this giant predator were recovered and prepared and have formed the object of a joint study, the results of which will be published in this week's edition of the journal Nature.

The morphology of the newly discovered sperm whale differs considerably from that of the modern sperm whale. Despite its similar size, with a skull which is 3 metres long and an estimated total body length of between 13.5 and 17.5 metres, this animal, which has been named Leviathan melvillei in honour of Herman Melville and his famous novel “Moby Dick”, has extremely strong teeth (on the lower jaw as well as the upper jaw). In fact, the largest teeth are more than 36cm long and have a diameter which can reach 12cm!

Given its size and the strength of its jaws and teeth, Leviathan was probably a superpredator, capable of feeding on large prey by trapping it in its powerful jaws and using its impressive teeth to kill it. Furthermore, Leviathan was discovered in geological layers dating from an epoch (end of the middle Miocene) during which the diversity of mysticetes (baleen whales) considerably increased. Some species of whale also reached significant sizes (around ten metres). Therefore, scientists have put forward the hypothesis that this large predator fed on baleen whales, as a large number of skeletons have been found at the Cerro Colorado site, where Leviathan was discovered.

It is also interesting to note that the teeth of another very large marine predator, the giant fossil shark Carcharocles megalodon, have also been discovered in large numbers at the Cerro Colorado site. So there could have been two superpredators fighting over prey with a very high nutritional value - baleen whales.

While the descendants of squid-hunting sperm whales have survived into our times, as modern sperm whales (Physeter), Leviathan and other predatory sperm whales disappeared at the end of the Miocene or Pliocene epochs. Scientists still do not know why, but decreased diversity in their prey, baleen whales, at the end of the Miocene period, as well as climate change, may have played a role in their extinction. During the Pliocene, another group of toothed cetaceans would specialize in hunting large marine mammals; this group includes modern killer whales, Orcinus orca. Although significantly smaller than Leviathan (total size of less than 9 metres), through working together, killer whales are able to kill and consume large cetaceans (rorquals, humpback whales, grey whales, etc.).

This giant sperm whale's skull is on display at the Lima Natural History Museum (Peru).

Centre National de la Recherche Scientifique

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