A DRUG which minimises brain damage when given three hours after stroke has proved successful in monkeys and humans. A lack of oxygen in the brain during a stroke can cause fatal brain damage. There is only one approved treatment - tissue plasminogen activator - but it is most effective when administered within 90 minutes after the onset of stroke. Immediate treatment isn't always available, however, so drugs that can be given at a later time have been sought. In a series of experiments, Michael Tymianski and colleagues at Toronto Western Hospital in Ontario, Canada, replicated the effects of stroke in macaques before intravenously administering a PSD-95 inhibitor, or a placebo. PSD-95 inhibitors interfere with the process that triggers cell death when the brain is deprived of oxygen. To test its effectiveness the team used MRI to measure the volume of damaged brain for 30 days following the treatment, and conducted behavioural tests at various intervals within this time. Monkeys treated with the PSD-95 inhibitor one hour after stroke had 55 per cent less damaged tissue in the brain after 24 hours and 70 per cent less after 30 days, compared with those that took a placebo. These animals also did better in behavioural tests. Importantly, the drug was also effective three hours after stroke (Nature, DOI: 10.1038/nature10841). © Copyright Reed Business Information Ltd

Keyword: Stroke
Link ID: 16462 - Posted: 03.01.2012

By BENEDICT CAREY Daily doses of a drug used to treat Parkinson’s disease significantly improved function in severely brain-injured people thought to be beyond the reach of treatment, scientists reported on Wednesday, providing the first rigorous evidence to date that any therapy reliably helps such patients. The improvements were modest, experts said, and hardly amounted to a cure, or a quick means of “waking up” someone who has long been unresponsive. But the progress was meaningful, experts said, and, if replicated, would give rehabilitation doctors something they have never had: a standard treatment for injuries that are not at all standard or predictable in the ways they affect the brain. Some 50,000 to 100,000 Americans live in states of partial consciousness, and perhaps 15,000 in an unresponsive “vegetative” condition. According to the Department of Defense, more than 6,000 veterans have had severe brain injuries since 2000 and would potentially benefit from this therapy. The new report, appearing in The New England Journal of Medicine, gives doctors a solid basis to address such injuries, if not yet a predictable outcome. “This study puts the traumatic brain injury field on the first step of the ladder to developing scientific treatments. We’ve been trying to get there for a long time,” said Dr. Ramon Diaz-Arrastia, director of clinical research at the Center for Neuroscience and Regenerative Medicine at the Uniformed Services University of the Health Sciences in Rockville, Md., who was not involved in the research. “And there’s no reason to doubt that this therapy would also be effective in people with less severe brain injuries” than in the study. © 2012 The New York Times Company

Keyword: Brain Injury/Concussion; Parkinsons
Link ID: 16461 - Posted: 03.01.2012

By Sheila Eldred In the weeks and months following a tragedy like this week's school shooting in Ohio, experts and lawyers and school psychologists and classmates will try to make sense of the actions of the 17-year-old suspect. In all likelihood, though, no one will ever be able to pinpoint a single reason, said pyschologist David Walsh, author of "Why Do They Act That Way? A Survival Guide to the Adolescent Brain for You and Your Teen." "There are usually multiple factors that take a long time to sort out," Walsh said. "It's irrational, so looking for a reason can be somewhat frustrating. There are many kids who probably share that profile who don't do anything remotely like what he did. Science, however, can shed some light on how he and other teenagers think. "Adolescents can make good decisions," insists B. J. Casey, a neuroscientist at Weill Cornell Medical College. "They can make better decisions than you or I. But it is in the heat of the moment that they get into trouble." That's because the reward-sensitive areas of the brain are maturing with the onset of puberty. There's been a long-held view that teens make poor decisions because they don't think through consequences. Since the 1990s, we've known that brains go through extensive development in adolescence. © 2012 Discovery Communications, LLC

Keyword: Development of the Brain; Emotions
Link ID: 16460 - Posted: 03.01.2012

By Janet Raloff Exposure to certain pollutants early in a rat’s pregnancy can foster disease in her offspring during their adulthood as well as in subsequent generations, a new study shows. A wide range of pollutants elicited such lasting effects, despite future generations never encountering the triggering pollutant. Some chemicals tested led to premature puberty among great-granddaughters, with an increased risk of disease in reproductive tissues. In some tests, the chemicals disrupted ovarian function, something that in humans could lead to infertility or premature menopause. And another chemical exposure caused premature death of sperm-forming cells in the great-grandsons, researchers report online February 28 in PLoS ONE. Rather than altering genes, the tested pollutants altered chemical switches that regulate genes, reports Michael Skinner and his colleagues at Washington State University in Pullman. These epigenetic switches can lock a gene on or off. These master switches for DNA are fairly easy to modify throughout life. Early in development, a fetus erases any epigenetic changes acquired during its parents’ lifetimes, resetting those switches back to healthy, default programming. Because the fetus has a mechanism to erase such changes, a pollutant’s epigenetic effects shouldn’t occur in subsequent generations, says epigeneticist John McCarrey of the University of Texas at San Antonio, who was not involved in the study. That they did emerge in the new study “is pretty heavy in terms of their potential significance,” he says. © Society for Science & the Public 2000 - 2012

Keyword: Development of the Brain; Epigenetics
Link ID: 16459 - Posted: 03.01.2012

by Elizabeth Norton Bottlenose dolphins have a knack for language. They can understand both the meaning and the order of words conveyed through human hand gestures—correctly putting an item on the right side of their tank into a basket on the left, for example. Now humans, too, are beginning to understand dolphin language as more than just a cacophony of clicks, pulses, and whistles. A new study shows that dolphins use their own unique calls, known as signature whistles, to introduce themselves to others when meeting at sea. Until recently, researchers could study signature whistles only in captive animals—raising the question of whether the whistle developed in response to capture, isolation, or stress. A 2004 study showed that a group of free-swimming bottlenose dolphins in Florida did indeed use signature whistles. But information about how they used these sounds was scant. Marine biologists Vincent Janik and Nicola Quick of the Sea Mammal Research Unit at the University of St. Andrews in the United Kingdom were focusing on signature whistles as a way of understanding how dolphins communicate in the natural world. "Dolphins are comparable to great apes in their cognitive skills, but all we know is what they do in a lab," Janik explains. "We wanted to understand how dolphins use their intelligence outside of the tasks that humans set for them." © 2010 American Association for the Advancement of Science.

Keyword: Animal Communication; Language
Link ID: 16458 - Posted: 03.01.2012

By Jason G. Goldman When you dive into the frigid waters of the Pacific Ocean off the coast of southern California, the first thing you notice is the silence. Other than the bitter cold. Your body begins to adapt to the chilly water as blades of slimy kelp brush across your ankles. You spit out the bit of brackish saltwater that inevitably seeps into your mouth. Then you quickly dunk your head into the sea so that you might wet your hair and wipe it away from your eyes. It’s in that moment – when you’re entirely submerged under the rolling waves – that you notice the silence. You can almost hear the oscillating thuds of the waves breaking against the sand. As your heart beats faster to push warm blood into your arms and legs, perhaps you might even be able to hear your own heartbeat. Even against the auditory backdrop of the pounding of the waves and your heart, you can’t help but perceive the quiet. If only it were so for the blue whales that call this corner of the ocean home, at least for part of the year. Each summer, groups of endangered blue whales (Balaenoptera musculus) pass along the coast of Southern California between San Diego and Los Angeles. It isn’t a secret that the ocean is a noisy place if you’re a whale. In addition to the natural soundscape of the ocean, whales can hear sounds that have human origins, like sonar, passing ships, or underwater explosions. Considerable scientific attention has been paid to the effects of high-intensity anthropogenic noise on the communication abilities of whales and other marine mammals. After all, these animals communicate over vast distances by producing clicks, whistles, and songs. Previous findings have confirmed that the presence of ships interrupts blue whale songs. And some whales have been observed increasing the amplitude of their foraging calls in noisy environments, in an effort to aid others in distinguishing their communication from the undersea cacophony. Imagine having to pick out the sounds of only the cellos from amid an entire orchestra. © 2012 Scientific American

Keyword: Animal Communication; Hearing
Link ID: 16457 - Posted: 03.01.2012

The belief that older people tend to suffer worse sleep may be false - in fact the reverse may be true, according to US researchers. A telephone survey of more than 150,000 adults suggested that, apart from a blip in your 40s, sleep quality gets better with age. Those in their 80s reported the best sleep, says the study in Sleep journal. A UK sleep researcher said while poor health could affect sleep, it was a "myth" that age alone was a factor. While universities have equipment which can measure sleep duration and disturbance in study volunteers, this does not always match the volunteer's own opinion on their night's rest. The research, conducted by the Center for Sleep and Circadian Neurobiology at the University of Pennsylvania, instead focused on asking large numbers of randomly selected people about their sleep. They were also asked about their race, income, education, mood and general health. While being depressed or having health problems was linked to poor sleep quality, once the researchers had adjusted the results to compensate for this, a distinct pattern emerged. BBC © 2012

Keyword: Sleep; Development of the Brain
Link ID: 16456 - Posted: 03.01.2012

By Stephen Dougherty Today anesthetics are considered as routine as a trip to the dentist. They have been around at least since the 18th century when a talented chemist named Humphry Davy discovered the mysterious effect of nitrous oxide (laughing gas). Davy, young and ambitious, set out to rigorously test the gas’s effect, inhaling nitrous oxide daily for several months. Under slightly less rigorous conditions, Davy shared the gas with a distinguished group of friends including Samuel Taylor Coleridge, James Watt, and Robert Southey—who wrote in a letter that “the atmosphere of the highest of all possible heavens must be composed of this gas.” These early trials laid the foundation for anesthesia’s emergence in medicine today. Yet in the modern era, despite tremendous advances in the quality and selectivity of anesthetics, we still have a poor understanding of how anesthetics work in the brain. Highlighting these fundamental gaps in knowledge, a group of researchers recently made a surprising discovery about how we transition out of consciousness and back. The common view holds that going under (induction) and coming back up (emergence) are the same process, albeit in different directions. However, a recent study published in the journal PLoS ONE suggests that going under is not the same as coming back up. The researchers, led by Dr. Max Kelz at the University of Pennsylvania School of Medicine, observed that less anesthetic is required to keep the brain anesthetized than to induce unconsciousness. To explain these observations, the researchers have introduced a concept they call “neural inertia,” referring to the brain’s resistance to transitions between consciousness and unconsciousness. © 2012 Scientific American

Keyword: Sleep
Link ID: 16455 - Posted: 03.01.2012

By Lena Groeger Our five senses–sight, hearing, touch, taste and smell–seem to operate independently, as five distinct modes of perceiving the world. In reality, however, they collaborate closely to enable the mind to better understand its surroundings. We can become aware of this collaboration under special circumstances. In some cases, a sense may covertly influence the one we think is dominant. When visual information clashes with that from sound, sensory crosstalk can cause what we see to alter what we hear. When one sense drops out, another can pick up the slack. For instance, people who are blind can train their hearing to play double duty. Those who are both blind and deaf can make touch step in—to say, help them interpret speech. For a few individuals with a condition called synesthesia, the senses collide dramatically to form a kaleidoscope world in which chicken tastes like triangles, a symphony smells of baked bread or words bask in a halo of red, green or purple. (For more on how the senses can cross each other and into unusual territory, see “Edges of Perception,” by Ariel Bleicher, Scientific American Mind, March/April 2012.) Our senses must also regularly meet and greet in the brain to provide accurate impressions of the world. Our ability to perceive the emotions of others relies on combinations of cues from sounds, sights and even smells (see “I Know How You Feel,” by Janina Seubert and Christina Regenbogen, Scientific American Mind, March/April 2012). Perceptual systems, particularly smell, connect with memory and emotion centers to enable sensory cues to trigger feelings and recollections, and to be incorporated within them. © 2012 Scientific American

Keyword: Vision; Hearing
Link ID: 16454 - Posted: 03.01.2012

By Stephani Sutherland The lifelong mental benefits of exercising have long been known, from improving learning in kids to staving off dementia in seniors. Yet how working up a sweat leads to better cognition is much less clear. A study in the Journal of Applied Physiology reveals that the key may lie in the body’s power supply. Just as a booming metropolis might build new power plants to meet a rising need for electricity, our muscles respond to the demands of exercise by producing new mitochondria, the tiny structures inside cells that supply the body with energy. J. Mark Davis, a physiologist at the University of South Carolina, and his colleagues wondered if brain cells might do the same thing. While studying mice, they found that quantities of a signaling molecule, dubbed by researchers “a master regulator” of mitochondria production, increased in the brain after half an hour a day of treadmill running. The mice’s brain cells also had more mitochondrial DNA—distinct from the regular cellular DNA found in the nucleus—providing “gold standard” evidence of more mitochondria. It appears that the brain “adapts and changes by bringing more of these power­houses” online, Davis says. The increased energy supply allows the brain to work faster and more efficiently. The finding could help scientists understand how exercise staves off age- and disease-related declines in brain function, because neurons naturally lose mito­chondria as we age, Davis explains. Although past research has shown that exercise encourages the growth of new neurons in certain regions, the widespread expansion of the energy supply could underlie the benefits of exercise to more general brain functions such as mood regulation and dementia pre­vention. “The evidence is accumulating rapidly that exercise keeps the brain younger,” Davis says. © 2012 Scientific American

Keyword: Alzheimers
Link ID: 16453 - Posted: 03.01.2012

By Maia Szalavitz Sticks and stones may break your bones, but names can hurt just as much. Indeed, according to converging evidence reported in a new review in Current Directions in Psychological Science, physical and social pain are processed in some of the same regions of the brain. Naomi Eisenberger, co-director of the Social Cognitive Neuroscience Lab at UCLA, published the first brain-imaging paper revealing the overlap in 2003. She had been studying participants’ reactions to being rejected by other players (actually just a computer opponent) in a video game. “The first time we noticed the similarity, I was analyzing data next to a colleague of mine who was analyzing data on physical pain in irritable bowel syndrome,” she says. “We noticed similarities in the way that the neural data looked.” Physical pain has two components, Eisenberger explains: sensory and emotional. The sensory part of physical pain is mapped in the brain depending on which part of the body is hurt, but the emotional component — how distressing your brain determines the pain to be — is registered in the dorsal anterior cingulate cortex (dACC). That’s also where the sting of social pain is processed. “The affective component, which tells you more how much the pain is bothering [you], how much suffering it is causing — that experience seems to be more localized to the dACC and the anterior insula,” Eisenberger says. © 2012 Time Inc.

Keyword: Emotions; Pain & Touch
Link ID: 16452 - Posted: 03.01.2012

How many neurons are there in the human brain? It was a question that scientists thought they had nailed – and the answer was 100bn (give or take). If you went looking you would find that figure repeated widely in the neuroscience literature and beyond. But when a researcher in Brazil called Dr Suzana Herculano-Houzel started digging, she discovered that no one in the field could actually remember where the 100bn figure had come from – let alone how it had been arrived at. So she set about discovering the true figure (HT to the excellent Nature neuroscience podcast NeuroPod). This involved a remarkable – and to some I suspect unsettling – piece of research. Her team took the brains of four adult men, aged 50, 51, 54 and 71, and turned them into what she describes as "brain soup". All of the men had died of non-neurological diseases and had donated their brains for research. "It took me a couple of months to make peace with this idea that I was going to take somebody's brain or an animal's brain and turn it into soup," she told Nature. "But the thing is we have been learning so much by this method we've been getting numbers that people had not been able to get … It's really just one more method that's not any worse than just chopping your brain into little pieces." She told me that so far, she has only looked at four brains, all of them from men. © 2012 Guardian News and Media Limited

Keyword: Miscellaneous
Link ID: 16451 - Posted: 03.01.2012

By NICHOLAS BAKALAR Low blood levels of omega-3 fatty acids are associated with smaller brain volume and poorer performance on tests of mental acuity, even in people without apparent dementia, according to a new study. In the analysis, published online Monday in the journal Neurology, scientists examined 1,575 dementia-free men and women whose average age was 67. The researchers analyzed the fatty acids of the subjects’ red blood cells, a more reliable measurement than a plasma blood test or an estimate based on diet. They used an M.R.I. scan to measure brain volume and white matter hyperintensities, a radiological finding indicative of vascular damage. People in the lowest one-quarter for omega-3 levels had significantly lower total cerebral brain volume than those in the highest one-quarter, even after adjusting for age, body mass index, smoking and other factors. They also performed significantly worse on tests of visual memory, executive function and abstract memory than those in the highest one-quarter. There was no significant association with white matter hyperintensity volume. “We feel that omega-3’s reduce vascular pathology and thus reduce the rate of brain aging,” said Dr. Zaldy S. Tan, the lead author and associate professor of medicine at the University of California, Los Angeles. Few in the study were taking omega-3 supplements, Dr. Tan said. The main reason that some had higher blood levels of omega-3’s was that they ate more fatty fish. © 2012 The New York Times Company

Keyword: Alzheimers
Link ID: 16450 - Posted: 02.28.2012

By RONI CARYN RABIN Many people are unaware that dozens of painkillers, antihistamines and psychiatric medications — from drugstore staples to popular antidepressants — can adversely affect brain function, mostly in the elderly. Regular use of multiple medications that have this effect has been linked to cognitive impairment and memory loss. Called anticholinergics, the drugs block the action of the neurotransmitter acetylcholine, sometimes as a direct action, but often as a side effect. Acetylcholine is a chemical messenger with a range of functions in the body, memory production and cognitive function among them. The difficulty for patients is that the effect of anticholinergic drugs is cumulative. Doctors are not always aware of all of the medications their patients take, and they do not always think to review the anticholinergic properties of the ones they prescribe. It’s a particular problem for older patients, who are more vulnerable to the effects of these drugs and who tend to take more medicines over all. Now a spate of new research studies has focused on anticholinergic medicines. After following more than 13,000 British men and women 65 or older for two years, researchers found that those taking more than one anticholinergic drug scored lower on tests of cognitive function than those who were not using any such drugs, and that the death rate for the heavy users during the course of the study was 68 percent higher. © 2012 The New York Times Company

Keyword: Drug Abuse; Alzheimers
Link ID: 16449 - Posted: 02.28.2012

By Michelle Roberts Health reporter, BBC News Sleeping pills used by thousands of people in the UK appear to be linked with a higher death risk, doctors warn. The American study in BMJ Open compared more than 10,000 patients on tablets like temazepam with 23,000 similar patients not taking these drugs. Death risk among users was about four times higher, although the absolute risk was still relatively low. Experts say while the findings highlight a potential risk, proof of harm is still lacking. They say patients should not be alarmed nor stop their medication, but if they are concerned they should discuss this with their doctor or pharmacist. UK guidelines for NHS staff say hypnotic drugs should only be used for short periods of time because of tolerance to the drug and the risk of dependency. But they make no mention of an associated death risk, despite other studies having already reported this potential risk. The Medicines and Healthcare products Regulatory Agency said it would consider the results of this latest study and whether it has any implications for current prescribing guidance. BBC © 2012

Keyword: Sleep
Link ID: 16448 - Posted: 02.28.2012

By Laura Sanders SALT LAKE CITY — When it comes tough financial decisions, people are often clueless. But some cash-savvy nerve cells deep in the brain know what to do. And these cells know the plan seconds before the person actually decides on a course of action, new research shows. The findings, presented February 25 at the Computational and Systems Neuroscience meeting, may help scientists understand how people make difficult decisions. Shaun Patel of Massachusetts General Hospital and colleagues enlisted eight people undergoing experimental therapy to alleviate severe depression or obsessive-compulsive disorder that involved implanting electrodes deep into the brain. During surgery, the electrodes eavesdropped on the behavior of individual nerve cells in an otherwise unreachable area of the brain called the nucleus accumbens. Other places in the brain feed lots of diverse signals to the nucleus accumbens: Information about a person’s emotions, memories and more sophisticated reasoning — key ingredients for decision making — all flow into this area. While in the operating room, participants played about 250 rounds of a simplified version of the card game “War,” in which two players each receive a card, and the higher card wins. The deck contained only cards numbered 2, 4, 6, 8 and 10 — all spades. © Society for Science & the Public 2000 - 2012

Keyword: Attention; Consciousness
Link ID: 16447 - Posted: 02.28.2012

by Daniel Strain Red dresses muddle men's minds, just ask The Matrix's Neo. In a scene from the 1999 sci-fi film, the hero is famously ambushed after becoming distracted by a woman on the street wearing a slinky red outfit. Now, a new study shows how such duds attain their sway. Men rate women wearing red clothing as being more interested in sex, hinting that humans may be conditioned to associate the color with fertility. The pull of red is nothing new. Women have donned pinkish blush and bright lipstick for nearly 12,000 years. And, if you're lucky enough to get a Valentine's Day card, it will probably come decorated in tiny red hearts. It's an effect that likely stems from biology, says Adam Pazda, a psychologist at the University of Rochester in New York state and an author of the new study. When many primate females—from chimpanzees to types of baboons called mandrills—become fertile, their estrogen levels peak, opening up their blood vessels and turning their faces bright red. This flushed complexion seems to give males the signal that it's time to make their move. The same could be true for humans, Pazda says. In a previous study, scientists showed that men seem to be more attracted to women clothed in red rather than in a blah color such as white. That's regardless of the cut, he adds. "It doesn't have to be a red dress or a sexy outfit," he says. "It can be a red T-shirt." To understand why, Pazda and his colleagues conducted a simple experiment. They showed 25 men a photo of a single woman doctored to look, in different cases, like she was wearing either a red or white T-shirt. The researchers then asked the volunteers to gauge, on a scale from 1 to 9, how keen the model seemed to be on romance. In other words, the men answered the question: "Is she interested in sex?" © 2010 American Association for the Advancement of Science.

Keyword: Sexual Behavior; Emotions
Link ID: 16446 - Posted: 02.28.2012

by Michael Marshall WHEN a new leader takes control of a troop of gelada monkeys, he is likely to kill the offspring of his predecessor. His arrival is also bad news for young yet to be born: they'll be aborted within weeks. Named for Hilda Bruce who first observed it in mice, the "Bruce effect" is common in lab animals. In fact, some biologists suspect it is an artefact of keeping animals in labs. Jacinta Beehner of the University of Michigan in Ann Arbor and colleagues have now found evidence of the effect in wild geladas (Theropithecus gelada), an Ethiopian monkey related to baboons. They found that the number of births fell sharply in the six months after a new dominant male took over a group, suggesting females were aborting their fetuses. As a check, Beehner took hormone samples from females' faeces, allowing her to track 60 pregnancies closely. Of nine failures, eight occurred in the two weeks after the father was replaced. Beehner says the strategy makes sense, because females don't want to waste energy on offspring likely to be killed after they are born. We don't know how the females do it, says Peter Brennan of the University of Bristol, UK, who was not part of the study. It may simply be a response to the stress of the takeover. Journal reference: Science, DOI: 10.1126/science.1213600 © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Evolution
Link ID: 16445 - Posted: 02.28.2012

By Karen Weintraub Marjorie Nicholas, associate chairwoman of the department of communication sciences and disorders at the MGH Institute of Health Professions, is an expert in the language disorder aphasia, and has been treating former Arizona Representative Gabrielle Giffords, who has the condition. Q. What is aphasia and how do people get it? A. Aphasia affects your ability to speak, to understand language, to read and to write. It’s extremely variable. Some might have a severe problem in expression but really pretty good understanding of spoken language, and somebody else might have a very different profile. Typically, people get aphasia by having a stroke that damages parts of the left side of the brain, which is dominant for language. People can also get aphasia from other types of injuries like head injuries, or in Gabby’s case, a gunshot wound to the head that damages that same language area of the brain. It is more common than people realize. Q. How does Giffords fit into the spectrum of symptoms you’ve described? A. Her understanding of spoken language is really very good. Her difficulties are more in the expression. Q. You obviously can’t violate her privacy, but what can you say about your work with Giffords? A. I worked with her for two weeks last fall, and [colleague Nancy Helm-Estabrooks of the University of North Carolina] and I are planning to work with her again for a week this spring. We’ll need to see where she is again. I’m assuming she will have continued to improve and we’ll want to keep her going on that track. © 2012 NY Times Co

Keyword: Language; Brain Injury/Concussion
Link ID: 16444 - Posted: 02.28.2012

By NATALIE ANGIER You may think you’re pretty familiar with your hands. You may think you know them like the back of your hand. But as the following exercises derived from the latest hand research will reveal, your pair of bioengineering sensations still hold quite a few surprises up their sleeve. • Make a fist with your nondominant hand, knuckle side up, and then try to extend each finger individually while keeping the other digits balled up tight. For which finger is it extremely difficult, maybe even impossible, to comply? • Now hold your hand palm up, fingers splayed straight out, and try curling your pinky inward without bending the knuckles of any other finger. Can you do it? • Imagine you’re an expert pianist or touch-typist, working on your chosen keyboard. For every note or letter you strike, how many of your fingers will move? • You’re at your desk and, without giving it much thought, you start reaching over for your water bottle, or your pen. What does your hand start doing long before it makes contact with the desired object? And a high-five to our nearest nonhuman kin: • What is the most important difference between a chimpanzee’s hands and our own? (a) the chimpanzee’s thumbs are not opposable; (b) the chimpanzee’s thumbs are shorter than ours; or (c) the chimpanzee’s thumbs are longer than ours. © 2012 The New York Times Company

Keyword: Evolution; Muscles
Link ID: 16443 - Posted: 02.28.2012