Five thousand years ago, marauding waves of nomadic horsemen swept out of the bleak Caspian steppes across Eurasia. The Kurgans, as they’re now called, were a warring culture who imposed their leadership and language on large swathes of people. From its violent origins, their tongue would give rise to the world’s most successful language family—at least according to one theory among linguists.

Proto-Indo-European was the ancestral language that, over millennia, branched into hundreds of languages spoken by 45 percent of the world’s population, including English, Hindi, Russian, and Urdu. The location of its birth has been the subject of fiery debate for centuries.

A fascinating and contentious new study in Science supports an origins theory that couldn’t be more different from the Kurgan hypothesis. In this alternate scenario, the proto-language spread and evolved not through conquest, but rather with the gradual, peaceful expansion of agriculture out of present-day Turkey.

The research team reached this conclusion through the innovative use of computational models borrowed from evolutionary biology. Languages, like DNA, mutate at measurable rates. If you can trace the evolution of similar words across different languages, you should be able to project backwards to identify their points of divergence and ultimate origins. Full Article »

In 1996, when I was seven-and-a-half, approximately sixty miles north of Seattle, I counted bald eagles on the Skagit river. In that one morning, in about two hours, I saw 126 eagles. I know this because I kept count.

For the purpose, my dad had given me a clicker, a small sleek shiny metal device whose entire job was to be a number. The clicker had a satisfactorily cool feel to it and felt dense owing to its durable metal construction. On the right hand side was a silver knob with ridges. Twist the knob, and four centered analog dials with stenciled white Courier New numbers behind a centered crystal display would satisfactorily click-click-click and advance from 0000 to 9999 to reset the clicker. Further up, and closer to the side of the clicker, was a metal lever that looked something like a gas pedal that had been bent out of shape. It stuck out enough from the rest of the clicker that any absentminded flick of the fingers would advance the count by one. On the left hand side you could put your thumb through a rotating metal ring to make sure that the clicker did not fall out of your hand. Hence your number would stay with you, always a palm away at your fingertips.

I remember that first counting experience vividly because it was the beginning of a long indoctrination of the certainty that numbers provide. In the sixteen years since that time I could sleep soundly knowing exactly how many eagles I saw that crisp fall morning. Knowing was a satisfactory feeling. Counting seemed simple at the time, but my days of naïveté were numbered.

Are numbers really as certain as we make them out to be in school? From an early age we are taught to deal with numbers. Perhaps we learn how to count things we know the answer to, like the number of bananas or cookies on a Sesame Street set, because it is the easiest way to see how a three dimensional object can be represented, first by two dimensions (describing the object as a word), and then by something even simpler: a number. Flip through any children’s book, and you will also see collections of animals that are very countable and verifiable.

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Given only vocal cues, humans can identify fear faster in other voices than happiness, say researchers.

The cause lies in biological-survival imperatives. And the implications may prevent your next computer technical-support call from ending in a one-sided screaming match with a voice recording.

Understanding the time it takes to identify an emotion can help engineers develop better automated call centers, aid psychologists in training people with autism to learn subtle social cues, and assist public speakers to analyze the effectiveness of their speeches.

Researchers at McGill University in Canada and the Max Planck Institute for Human Cognitive and Brain Sciences in Germany have measured the time it takes for people to correctly identify certain emotions (anger, disgust, fear, sadness, happiness). Experimenters speak a neutral, meaningless phrase (e.g., The rivix jolled the silling), which is then broken into seven pieces based on syllables. The time each participant takes to react to each piece is recorded.

Marc Pell, from McGill University’s School of Communication Sciences and Disorders, says emotion recognition studies of the voice are important, though rarely studied compared with facial expression.

“When you look at a face, all of the information that will allow you to recognize the emotion is available instantaneously if you’re focusing on it,” says Pell. “What is different about the voice is that emotions have to evolve over time.” Full Article »

Researchers at MIT have designed a computer chip that emulates brain synapses—the junctions between neurons—at a new level of detail.

Recently, they’ve used these chips as a model to study how the connections between neurons strengthen over time, a process thought to be integral to learning and memory, according to a paper published in the Proceedings of the National Academy of Sciences.

But beyond helping us understand the brain, these chips could eventually be part of brain-machine interfaces used by amputees to control artificial limbs, says Chi-Sang Poon, senior author of the paper. Someday he believes they could even build prosthetic brain parts to replace damaged brain tissue—or to augment users’ natural abilities.

Since a neuron either fires or doesn’t, digital computers with their binary language of ones and zeroes seems ideal to replicate neuron activity. So scientists wanting to produce models of brain behavior often write programs or build digital systems that replicate neuron firing patterns.

But at a deeper level, neurons are more complicated than a simple on/off switch. Whether a neuron fires or not relies on a cascade of smaller internal processes dependent on the neuron’s ion channels—small “gates” through which charged particles can flow in and out of the cell. Therefore, while the outward behavior of the neuron can be captured in the black-or-white of a digital system, what happens on the inside is characterized by infinite shades of gray. So Poon and his colleagues have recreated these immensely complex processes at the level of the neuron’s ion channels in a more analog model.

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Psychiatrists in Germany have found a difference in brain arousal that marks men most vulnerable to sexual dysfunction upon taking antidepressant drugs.

By showing pornographic film clips to eighteen young men in a brain scanner, after a week of antidepressant treatment and sexual-function surveys, the researchers determined what goes wrong when these drugs cause sexual problems.

Men who showed high impulsiveness on a personality test were more likely to have trouble getting aroused and to show the weakened brain response to erotic movies. Psychiatrists may use this factor to predict depressed patients at risk for sex problems and to treat them.

Sexual dysfunction, especially difficulty achieving orgasm, is a common side effect of SSRIs, or serotonin-selective re-uptake inhibitors, the most prescribed antidepressants. Sexual problems are the main reason depressed patients stop taking their medicine, which can lead to suicide. So identifying the 64 percent of patients at risk for sexual side effects to SSRIs is an important concern in psychiatry.

In the German study, subjects reported sexual side-effects to an SSRI—the most popular type of antidepressants, which includes Prozac, Lexapro, Zoloft, Paxil, Celexa— more than on a placebo or bupropion, a non-serotonin antidepressant. Since bupropion can cause anxiety and sleeplessness, it is less often prescribed than serotonin-targeted antidepressants, but is less likely to cause sexual side effects. Full Article »

People who practice meditation show changes in alpha brain waves indicating improved attention, according to a study published in Brain Research Bulletin in May.

While the alpha brain wave long has been associated in a general way with meditation, this joint study conducted by researchers from Harvard Medical School, Massachusetts General Hospital (MGH), and MIT shows changes in the alpha wave after only eight weeks of meditation practice.

This alteration of the alpha wave after meditation training holds promise for people suffering from chronic pain, says Dr. Cathy Kerr, one of the lead authors on the study. First, she says, mindfulness training can lower pain intensity. Second, it may make patients better able to direct their attention away from painful areas—something chronic pain sufferers often find difficult; and third, the training may help patients break the cycles of “rumination,” or repetitive thoughts, that often develop in response to chronic pain. Upcoming research will examine explicitly how these meditation-mediated improvements in attention control affect pain and quality of life in chronic pain sufferers.

Kerr, who was part of the Osher Research Center at Harvard Medical School at the time of the study’s publication (she’s since moved to Brown University), says that the changes in the alpha waves of meditators’ brains suggest that they are better able to “turn down the volume” on irrelevant sensory input.

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Laughter is like dope: addictive and inebriating. People use laughs as social lubricant, the way we drink alcohol to ease tension and loosen up.

But this laughter high may be more than a metaphor, a study from Oxford University suggests. Laughing together may drug our brains with the opiates that numb pain. Laughter’s intoxicating effect on the brain, like the buzz we get from morphine, sex, or running, may also help hook us on companionship. The study’s lead author, Robin Dunbar, argues that humans may have evolved laughter to promote group-bonding.

When anthropologists showed groups of people fifteen-minute snippets of comedy videos, like The Simpsons, Friends, and Mr. Bean, as well as live-improv by the comedy troupe the Oxford Imps, the audience spent about a third of the time laughing. In contrast, subjects shown “neutral” videos—golf or nature shows—didn’t laugh at all.

Afterward, the scientists measured everyone’s pain tolerance using ice-cold wine sleeves, blood pressure cuffs, and a painful wall-squat. Viewers of the funny shows could stand pain significantly longer than the ones who watched boring or happy videos. This suggested that actual laughter dulled the pain, beyond the mere positive-vibe of the nature shows.

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It’s said a joy shared is doubled. There may be some truth to that. An international team of researchers has found that shared laughter makes us more resistant to pain: Five minutes of belly-laughing makes people less sensitive to pain by an average of ten percent.

The team, led by Robin Dunbar of the University of Oxford in England, tested people’s pain sensitivity before and after they watched a fifteen-minute film. Some saw bits of comedy (Mr. Bean, for example), while others watched something neutral (like a golf instruction video). To check that the effect didn’t just come from being put in a good mood, others watched feel-good videos that were positive without being funny. As the researchers found out, feel-good isn’t good enough. What people really needed was a good laugh.

It’s thought that laughter reduces pain by releasing endorphins, brain chemicals known for their pain-killing powers. But faked or forced laughter doesn’t cut it; only the spontaneous, contagious, eye-crinkling kind of laughter increases people’s pain tolerance. Full Article »

Impulse-control problems in delinquent teenagers may be driven by immature brain networks, a recent study of teen prisoners suggests, raising the possibility of early intervention to prevent crime.

Brain-network maturity relates to impulse-control in teenager law-breakers, the study found. The disturbing possibility that criminal behavior may be driven by brain abnormality may challenge our notion of guilt: Is the ethical response to crime punishment or mental-health treatment?

The new study, published in the journal Proceedings of the National Academy of Science in July, suggests that unusually impulsive teenagers may in part have children’s brains. Patterns of brain connectivity in the impulsive teens—how the motor-planning area talks to other parts—resembled those of younger children. If scientists understand the brain-dynamics behind such immaturity, they may design interventions to help “train the brain” to promote neural development that could “mature” deviant teenage convicts into healthy adults.

Dr. Ben Shannon of Washington University in St. Louis led the study which scanned the brains of 107 teenage inmates at a juvenile prison in New Mexico. Full Article »

There is a brain on an airplane, bound from Boston to San Francisco. This brain is disembodied, floating in a portable refrigerator, seatbelted next to a scientist, the neurologist Dr. Jacapo Annesse. His carry-on is one of the most famous brains in the world—freshly dissected out of patient HM. Yesterday, HM was alive. Today his brain is airborne while his 82-year-old body lies in a morgue in Boston. The memory of the man with no memory endures, even as his empty brain is flown across the country.

I remember the day HM died. I was working in a brain-imaging lab in Kyoto. I got to work to find four emails from friends in my old Memory Lab at Princeton. To memory researchers, the death of HM was a huge event. In the New York Times obituary, we finally learned his name: Henry Molaison.

Today you can see a slice of this brain on a wall at the MIT Museum—an exhibit courtesy of MIT professor Suzanne Corkin, a neuroscientist who worked with HM. The brain is stained in blue, labeled with red marker: “1953 surgical ablation”; “Temporal Lobe.” The two words and the picture tell what happened: a surgeon excised the middle of HM’s temporal lobes in 1953, when he was 27, as an experimental treatment for his epilepsy. What the picture doesn’t say is what the brain-surgery did to HM’s mind and to the history of neuroscience. That day Henry lost his hippocampus—the seahorse-shaped part in the brain beneath his temples— and he never formed another memory of an event in his life. Though he was born the same year as my grandfather, Henry was stuck forever with the memories of a man the age I am today. In the fifty years that followed—from studies on what HM could and could not learn, from what he did and did not remember after his surgery—neuroscience learned most of what we think we know about memory in the brain.

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