By BENEDICT CAREY Staring at a pattern meant to evoke an optical illusion is usually an act of idle curiosity, akin to palm reading or astrology. The dot disappears, or it doesn’t. The silhouette of the dancer spins clockwise or counterclockwise. The three-dimensional face materializes or not, and the explanation always seems to have something to do with the eye or creativity or even personality. The radiating lines trick the brain into perceiving motion forward, so the center appears to bulge. That’s the usual cue to nod and feign renewed absorption in the pattern. In fact, scientists have investigated such illusions for hundreds of years, looking for clues to how the brain constructs a seamless whole from the bouncing kaleidoscope of light coming through the eyes. Brain researchers today call the illusions perceptual, not optical, because the entire visual system is involved, and their theories about what is occurring can sound as exotic as anyone’s. In the current issue of the journal Cognitive Science, researchers at the California Institute of Technology and the University of Sussex argue that the brain’s adaptive ability to see into the near future creates many common illusions. “It takes time for the brain to process visual information, so it has to anticipate the future to perceive the present,” said Mark Changizi, the lead author of the paper, who is now at Rensselaer Polytechnic Institute. “One common functional mechanism can explain many of these seemingly unrelated illusions.” His co-authors were Andrew Hsieh, Romi Nijhawan, Ryota Kanai and Shinsuke Shimojo. Copyright 2008 The New York Times Company

Keyword: Vision
Link ID: 11698 - Posted: 06.24.2010

By Elsa Youngsteadt Sometimes seizures become a nightmare without end. Roughly 15% of epileptics will, at some point, experience status epilepticus, a medical emergency in which convulsions can only be stopped with strong anesthetics. Now researchers have found a piece of cellular machinery--an acid-activated ion channel-- that helps bring seizures under control. They hope the discovery will lead to new drugs that could stop these deadly events. For decades, researchers have suspected a link between brain acidity and seizures. In 1929, doctors noted that patients breathing CO2 had shorter seizures; the gas boosts the acidity of blood reaching the brain. Even without intervention, brain pH can drop during a seizure due to changes in breathing and metabolism. John Wemmie, a psychiatrist at the University of Iowa in Iowa City and colleagues wondered if an ion channel called ASIC1a might play a role, as it is known to activate neurons by pumping calcium and sodium across the cell membrane when the brain becomes acidic. Wemmie's team compared normal mice with those that were genetically engineered to lack the channel. When they injected these knockouts and controls with chemicals that cause epilepsy-like seizures, the normal mice fared much better than the ones without ASIC1a. A compound called kainate produced serious whole-body convulsions in all seven knockout mice, whereas the six normal mice had only minor seizures in their heads and fore-limbs. A second group of knockouts injected with a different drug, PTZ, had longer seizures than control mice--and those seizures were several times more likely to become deadly tonic-clonic whole-brain seizures (formerly known as "grand mal" seizures). In contrast, mice genetically engineered to have double the normal number of ASIC1a channels had shorter and less severe seizures than wild-type mice, the team reports online this week in Nature Neuroscience. © 2008 American Association for the Advancement of Science

Keyword: Epilepsy
Link ID: 11697 - Posted: 06.24.2010

-- Relentless evolution towards more intelligent species may have been driven not just by progressively larger brains but by the increasingly complex way in which they were wired, reports a study released Sunday. Scientists in Britain probing the origins of the human brain focused on the role of synapses, the junctions between nerves which transfer electrical signals -- and information -- from one brain cell to the next via a series of biochemical switches. Most research to date has assumed that synapses, made of proteins, are essentially the same in all animals, ranging from the lowly earthworm all the way up the evolutionary ladder to humans. What makes some species more intelligent than others, according to this prevailing wisdom, is sheer mass -- more neurons equals greater data-processing capacity. "The view that 'more nerves' is sufficient to explain 'more brain power' is simply not supported by our study," said lead researcher Seth Grant, who heads the Genes to Cognition Program at the Wellcome Trust Sanger Institute in Britain. Looking at the density and molecular makeup of synapses, the study, published in Nature Neuroscience, found dramatic differences between species. © 2008 Discovery Communications, LLC

Keyword: Evolution; Intelligence
Link ID: 11696 - Posted: 06.24.2010

Colin Barras The brain region responsible for one of humankind's neatest mental tricks may have been identified. We think nothing of singling out one person's voice at a party buzzing with people chatting. But researchers have struggled to understand just how the human brain manages to filter out a single thread of conversation from a tangle of similar background noises. The phenomenon was labelled the "cocktail party effect" in the 1950s by Colin Cherry, a British cognitive scientist. Now, if we don't know exactly how, at least we may know where. Researchers conducting brain scans of people listening to multiple sounds, say that the secondary auditory cortex – located in the temporal lobe at the side of the head – does much of the work. Hidden tone Alexander Gutschalk at the Ruprecht-Karl University of Heidelberg in Germany and his team decided to study brain activity during this "informational masking". They hooked volunteers up to a Magnetoencephalography (MEG) imager and played them a sound file containing a large number of randomly repeating tones across a range of frequencies. © Copyright Reed Business Information Ltd

Keyword: Hearing
Link ID: 11695 - Posted: 06.24.2010

By Susan Gaidos To the brain, remembering the past and visualizing the future look surprisingly similar When Alice climbs through the looking glass, she encounters a topsy-turvy world. People are punished before committing a crime, and sometimes fingers bleed before a pinprick occurs. Those strange events reflect a memory that works both ways in that world, allowing people to remember things before they happen. As the Queen explains to Alice: “It’s a poor sort of memory that only works backwards.” Now, back in this world, scientists are discovering that human memory does indeed work forward. A growing number of studies show that the mental machinery for reliving your past performs another—perhaps more vital—task: envisioning your future. Other studies show that total amnesiacs report a “blank” when asked about their personal futures. And severely depressed patients, who tend to think about both the past and future in a nonspecific manner, have difficulty visualizing positive future events. Such findings have stimulated scientists to rethink the role of memory. Rather than viewing it as a mere storehouse of facts and autobiographical data, researchers are beginning to recognize that memory also constructs, simulates and predicts possible future events in an ever-changing environment. Perhaps, some say, this kind of autobiographical memory exists precisely for this purpose. © Society for Science & the Public 2000 - 2008

Keyword: Learning & Memory
Link ID: 11694 - Posted: 06.24.2010

By Lauren Cahoon Call it the chicken-and-egg debate of the addiction world: Cocaine addicts are known for being frenetic, but which came first, the behavior or the habit? New research indicates that, at least in rats, it's the behavior that begets addiction. What's more, the study has pinpointed the character trait--impulsiveness--that is responsible for developing true drug dependence. Experts believe that the findings may lead to new approaches for treating addiction. Scientists who study drug addiction have a common problem: The individuals they deal with are already addicted, so it's hard to tell what, if any, behaviors led to the initial dependence. What they do know is that two traits--impulsiveness and thrill-seeking--tend to define most drug addicts. Although the behaviors are similar, scientists have been able to parse them in the lab: Highly impulsive rats jump the gun on simple tasks--pushing a button, for example, before they are signaled to do so; thrill-seeking rats, meanwhile, will rapidly explore any new environment--immediately sniffing various objects in a new cage, for example--whereas normal rats would wait until they felt comfortable in their surroundings. In hopes of discovering if either of these two traits might be a catalyst for drug addiction, psychologists David Belin and Barry Everitt, both of the University of Cambridge in the U.K., hooked up the sensation-seeking rats and the impulsive rats to a device that dispensed cocaine directly into the rats' brains. The rats could control the dispenser, so they could take the cocaine whenever they wanted. As the team reports in today's issue of Science, the thrill seekers tried the cocaine immediately, taking it in sky-high doses. The impulsive rats weren't as quick to turn to the drug, however, and when they did, they took it in smaller amounts. © 2008 American Association for the Advancement of Science.

Keyword: Drug Abuse
Link ID: 11693 - Posted: 06.24.2010

Daniel Cressey Controlling your anger and reacting sensibly when someone treats you badly can be a problem. And if you have low levels of serotonin, it can be even more of a problem, a new study has found. Molly Crockett at the University of Cambridge, UK, and her colleagues gave volunteers a drink that temporarily lowered their levels of serotonin, a brain 'neurotransmitter' linked to happy mood. They then had them play ‘the Ultimatum Game’, which involves accepting or rejecting offers of money. Those with lower serotonin levels showed increased retaliation to offers that they perceived to be unfair. “We’ve suspected for years that there’s a link between serotonin and impulsive aggression and emotional regulation,” says Crockett. “Until this study it wasn’t clear whether serotonin was playing a causal role.” It has long been known that low serotonin levels are associated with groups of people prone to impulsiveness and problems with emotional control, such as alcoholics, violent criminals and suicide attempters. Low serotonin is also found in clinical conditions such as depression and anxiety. “We’ve known for 30 years that low serotonin is associated with impulsivity, inwardly directed aggression and outwardly directed aggression,” says David Nutt, head of the Psychopharmacology Unit at the University of Bristol’s Faculty of Medicine and Dentistry, who was not involved in the new study. “What we are doing now is externally manipulating it. We need to study it in a more controlled environment.” © 2008 Nature Publishing Group

Keyword: Emotions; Aggression
Link ID: 11692 - Posted: 06.24.2010

An active social life appears to delay memory loss as we age, a new study shows. The finding, which appears in the July issue of The American Journal of Public Health, suggests that strong social ties, through friends, family and community groups, can preserve our brain health as we age and that social isolation may be an important risk factor for cognitive decline in the elderly. Researchers at the Harvard School of Public Health used data gathered from 1998 to 2004 from the Health and Retirement Study, a large, nationally representative population of American adults ages 50 and older. Participants took memory tests at two-year intervals during the study period. Testers read a list of 10 common nouns to survey respondents, who were then asked to recall as many words as possible immediately and again after a five-minute delay. The researchers also measured social integration based on marital status, volunteer activities, and contact with parents, children and neighbors. The results showed that individuals who in their 50s and 60s engaged in a lot of social activity also had the slowest rate of memory decline. In fact, compared to those who were the least socially active, study subjects who had the highest social integration scores had less than half the rate of memory loss. The researchers controlled for variables like age, gender, race and health status. Those who had the fewest years of formal education appeared to have the most to gain from an active social life as they aged. The study showed that the protective effect of social integration was greatest among individuals with fewer than 12 years of education. Copyright 2008 The New York Times Company

Keyword: Alzheimers; Learning & Memory
Link ID: 11691 - Posted: 06.05.2008

By Seth Borenstein WASHINGTON - A little strategically placed makeup quickly turns the wimpiest of male barn swallows into chick magnets, amping up their testosterone and even trimming their weight, new research shows. It's a "clothes make the man" lesson that — with some caveats — also applies to human males, researchers say. Using a $5.99 marker, scientists darkened the rust-colored breast feathers of male New Jersey barn swallows, turning lighter birds to the level of those naturally darkest. They had already found, in a test three years ago, that the marked-up males were more attractive to females and mated more often. This time they found out that the more attractive appearance, at least in the bird world, triggered changes to the animals' body chemistry, increasing testosterone. "Other females might be looking at them as being a little more sexy, and the birds might be feeling better about themselves in response to that," said study co-author Kevin McGraw, an evolutionary biology professor at Arizona State University. © 2008 The Associated Press.

Keyword: Sexual Behavior; Evolution
Link ID: 11690 - Posted: 06.24.2010

By John Bohannon Today's couch potato lifestyle has been blamed for skyrocketing rates of obesity, but the cause of this trend may have more to do with the potato than the couch. An analysis of 20 years of published data on people's daily energy expenditure indicates that overeating, rather than a sedentary existence, is the major cause of the industrial world's obesity epidemic. What is certain about obesity is that it is ultimately caused by an imbalance in people's energy budgets. When you take in more calories than you burn, your body squirrels the excess away as fat. The imbalance can stem from too much food, too little physical activity, or a combination of the two. Studies of self-reported exercise and eating habits have suggested that daily physical activity has decreased in recent decades, while daily caloric intake has remained steady. But people's accounting of their own behaviors is notoriously inaccurate. To get more reliable data, biologists Klaas Westerterp of Maastricht University in the Netherlands and John Speakman of the University of Aberdeen in the U.K. turned to a technique called the doubly labeled water (DLW) method. Over 2 weeks, subjects are given trace amounts of water molecules whose hydrogen or oxygen atoms contain extra neutrons. The body draws on the oxygen atoms for metabolism, expelling some of them in carbon dioxide. By tracking the ratio of heavy hydrogen and oxygen in the urine, researchers can estimate a person's overall rate of metabolism. © 2008 American Association for the Advancement of Science

Keyword: Obesity; Genes & Behavior
Link ID: 11689 - Posted: 06.24.2010

If you're a sucker for sweets, it might be in your genes. Researchers at the University of Toronto discovered a genetic difference in people who consume extra sugar in their diet. "Certainly environmental factors can influence the foods that we like and dislike," says nutrigenomics researcher Ahmed El-Sohemy. “But what this line of research demonstrates is that there is also a biological or a genetic basis for some of our likes and dislikes of foods." El-Sohemy and his colleagues studied two large groups of volunteers, who completed detailed records of their daily diet. Analyzing blood samples, they found that people with a different form of a gene called GLUT 2 had consistently higher daily sugar intakes. “Initially what we were interested in finding is why some people show a more dramatic rise in blood sugar after a meal,” El-Sohemy explains. “The reason we focused on this particular gene is because it’s known to function primarily in the pancreas. That’s the organ that’s responsible for sensing changes in blood sugar and producing insulin in response to clear it. We found there was no difference in how quickly individuals with the two versions of the gene cleared glucose from their blood, but surprisingly, those who had a particular version of this gene just consumed more sugar... the fat intake was the same, protein was the same, other types of carbohydrates was the same. So it seemed to be very specific to sugar.” © ScienCentral, 2000-2008.

Keyword: Genes & Behavior; Chemical Senses (Smell & Taste)
Link ID: 11688 - Posted: 06.24.2010

-- It doesn't pay to be smart and ignorance really is bliss if you want a long life -- at least if you're a fly, according to new research by a Swiss university. Scientists Tadeusz Kawecki and Joep Burger at the University of Lausanne said Wednesday they had discovered a "negative correlation between an improvement in a fly's mental capacity and its longevity". As part of their research project, the results of which are published in the journal Evolution, they divided into two a group of flies from the Basel region of northwestern Switzerland. One half was left in a natural state while the other had its intelligence boosted by Pavlovian methods, such as associating smell and taste with particular food or experiences. Over 30 to 40 generations, these methods led to flies which clearly learned better and remembered things for longer. The flipside was that the flies left in their natural state lived longer on average than their "cleverer" counterparts, with a lifespan of 80-85 days rather than the normal 50-60.. © 2008 Discovery Communications, LLC

Keyword: Learning & Memory; Evolution
Link ID: 11687 - Posted: 06.24.2010

Katharine Sanderson Human stem cells have been used to correct abnormal brain development in mice with fatal brain disorders, offering hope for treating a range of neurological disorders including some deadly childhood genetic diseases. Those behind the new treatment hope that human clinical trials could be just a few years away. The treatment uses human glial progenitor cells — cells that can differentiate into the glial cells that, among other things, make up myelin. Myelin, a protein that insulates the long 'arms' of nerve cells, called axons, helps the conduction of neural signals throughout the nervous system. A team led by Steven Goldman, at the University of Rochester in New York, took the progenitor cells from white matter in the fetal human brain and injected them into the spinal cords of mutant shiverer mice shortly after their birth. The mice, which shiver and shake as their name suggests, have severe neurological defects caused by a genetic mutation that stops them producing myelin. Without myelin, neural signals get stuck, causing potentially fatal disease. “There’s no way we’d be able to conduct a [neural] signal very far if it weren’t for myelin,” Goldman explains. As they develop, shiverer mice become unable to walk forwards, have increasing numbers of seizures, and typically die at just 18–21 weeks of age. © 2008 Nature Publishing Group

Keyword: Multiple Sclerosis; Glia
Link ID: 11686 - Posted: 06.24.2010

By Bob Guldin "Wow!" I said. "Is that a psychedelic light show?" I was at a party, and I could see a bright shimmer of purple across the room. It reminded me of my misspent rock-and-roll youth. My wife looked at me quizzically. "There's no light show; it's just a light," she said. I looked at it hard and could tell she was right. So what had I just seen? I didn't know it, but I had entered the unsettling sphere of retinal detachment, a Twilight Zone where you can't believe your eyes. And as I had yet to learn, recognizing the symptoms of a displacement of the light-sensitive tissue lining the eye could mean the difference between saving and losing your sight. In the weeks that followed, I saw more flashes of light that I knew weren't there. I saw growing numbers of "floaters," odd shapes that drifted across my field of vision. Once, while washing dishes, I panicked at the sight of a swarm of them congregating around a basket of bananas. Surprise! My floaters were actually fruitflies. (Somehow, I was not comforted.) When I got worried enough to visit my eye doctor, he told me my eye tricks might signal a developing tear or detachment of the retina, the layer of cells that receives images and sends them to the brain via the optic nerve. If you see something like a curtain crossing your vision from any direction, he warned, come in right away. © 2008 The Washington Post Company

Keyword: Vision
Link ID: 11685 - Posted: 06.24.2010

By DAN HURLEY There was nothing very interesting in Katherine P. Rankin’s study of sarcasm — at least, nothing worth your important time. All she did was use an M.R.I. to find the place in the brain where the ability to detect sarcasm resides. But then, you probably already knew it was in the right parahippocampal gyrus. What you may not have realized is that perceiving sarcasm, the smirking put-down that buries its barb by stating the opposite, requires a nifty mental trick that lies at the heart of social relations: figuring out what others are thinking. Those who lose the ability, whether through a head injury or the frontotemporal dementias afflicting the patients in Dr. Rankin’s study, just do not get it when someone says during a hurricane, “Nice weather we’re having.” “A lot of the social cognition we take for granted and learn through childhood, the ability to appreciate that someone else is being ironic or sarcastic or angry — the so-called theory of mind that allows us to get inside someone else’s head — is characteristically lost very early in the course of frontotemporal dementia,” said Dr. Bradley F. Boeve, a behavioral neurologist at the Mayo Clinic in Rochester, Minn. “It’s very disturbing for family members, but neurologists haven’t had good tools for measuring it,” he went on. “That’s why I found this study by Kate Rankin and her group so fascinating.” Copyright 2008 The New York Times Company

Keyword: Emotions; Brain imaging
Link ID: 11684 - Posted: 06.24.2010

Ewen Callaway They may never hustle a blackjack table, but nautiluses display a simple form of memory, according to new research. Unlike more cerebral cephalopods, such as cuttlefish, octopus and squid, the humble nautilus has a puny brain without the evolutionary flourishes that hint at memory. But a simple experiment reminiscent of Pavlov's work with dogs now shows that the deep-dwelling invertebrates can learn to associate a flash of light with food – and hold onto that memory for hours. "We were quite surprised to see memory at all," says Robyn Crook, a marine biologist at Brooklyn College in New York, who led the study. She, like most researchers, assumed the nautilus's daily trips up and down a coral reef didn't require memory. "Because their brain is so simple and because it lacks the dedicated learning regions of octopus and cuttlefish and squid it had been implied they would have some deficits in learning and memory," she says. Sometimes called living fossils, nautiluses seem to have changed little over millions of years. The shelled cephalopods spend their days at depths of around 300 metres, while at night they venture near the surface to feast on dead sea life. © Copyright Reed Business Information Ltd

Keyword: Learning & Memory; Evolution
Link ID: 11683 - Posted: 06.24.2010

The body's immune system could be harnessed to fight back against Alzheimer's disease, research suggests. Turning off a part of the immune system cleared away harmful brain deposits and improved memory, the mouse study found. US scientists, reporting their discovery in the journal Nature Medicine, said it was like a "vacuum cleaner" had been working in the brain. The Alzheimer's Society said more research would reveal if the process also worked in humans. Alzheimer's disease patients are gradually deprived of their memories and their ability to live normally. The damage is caused by the formation of "amyloid plaques" in their brain cells. Scientists have been searching for ways to break up and dispose of these plaques, and perhaps halting or even reversing the symptoms. So far, while there are some drugs which can delay the progress of the disease in some patients, there is no cure. One of the biggest obstacles to a successful treatment is the blood-brain barrier, which stops large molecules getting into the brain, ruling out many complex drugs which might otherwise be used. The researchers from Yale University took a different approach. They used genetic engineering to block an immune system response in mice, but only in cells outside the brain. Researchers had expected the change to worsen the Alzheimer's by sending the immune response into overdrive, causing too much inflammation inside the brain. But they found up to 90% of the plaque material disappeared from the brains of the mice. And when the animals' memories were tested using mazes, significant improvements were found. (C)BBC

Keyword: Alzheimers; Neuroimmunology
Link ID: 11682 - Posted: 06.02.2008

By SALLY SARA His Superman T-shirt was bold and bright, but his face was creased with confusion. Gerry Thomas was stumped by a question most men can answer in an instant. “What’s your favorite beer?” asked his sister, Beth Thomas. Mr. Thomas, 50, sitting in the house he and his sister share in Queens, squinted with intense concentration. He struggled to unravel the question, let alone remember the answer. Finally, he gave his sister an apologetic smile and shook his head. “I think I’m losing it,” he said. Doctors had predicted that Mr. Thomas, born with Down syndrome, would be lucky to reach his 10th birthday. His longevity has come at a price, though. Two years ago, it was determined that Mr. Thomas, at 48, had early-onset Alzheimer’s disease, adding new challenges of dementia to his already significant disabilities. In a cruel coincidence that scientists do not yet fully understand, research has shown that people with Down syndrome, a chromosomal abnormality, have a much higher incidence of Alzheimer’s disease at an early age. Some studies have said that 60 to 75 percent of people over age 60 with Down syndrome will have Alzheimer’s, though Dr. Ira Lott, who is in charge of the Down syndrome program at the School of Medicine at the University of California, Irvine, said those studies have been limited in scope. Copyright 2008 The New York Times Company

Keyword: Development of the Brain; Alzheimers
Link ID: 11681 - Posted: 06.24.2010

By Nikhil Swaminathan Although many neuroscientists are trying to figure out how the brain works, Mark Changizi is bent on determining why it works that way. In the past, the assistant professor of cognitive science at Rensselaer Polytechnic Institute has demonstrated that the shapes of letters in 100 writing systems reflect common ones seen in nature: Take the letter "A"—it looks like a mountain, he says. And "Y" might remind one of a tree with branches. He also showed that across different languages most characters take three strokes to write out. That's because, he says, three is the highest quantity a person's brain can perceive without resorting to counting. But Changizi's theories aren't limited to writing. He also believes that primates developed the ability to see in color so that they could figure out if peers were sending emotional cues. He hatched that theory by comparing the light wavelengths given off by the facial skin of someone blushing to that of a person not flushed. The prolific Changizi recently published two papers: one that sets out to explain how our lexical systems evolved and another that suggests how the brain's visual system is adapted to anticipate the future a fraction of a second before we actually see it. (See related slideshow here.) Changizi spoke to ScientificAmerican.com about his newest research; what his forthcoming book, The Vision R(evolution): How the Latest Research Overturns Everything We Thought We Knew About Human Vision, has to do with superheroes; and what kind of scientist he is. My goal is to understand the principles underlying the design of the brain or visual system or cultural artifact, like language or writing systems. I'm not as interested in the mechanisms per se. People like me make the point that you can't even study those mechanisms without having an idea what those mechanisms are trying to compute. So you have to have some opinion about what the design or function of those mechanisms are for to even do that. So, I am focusing on the function from a teleological [purposive] point of view. Of course it's unpacked with natural selection or cultural evolution. © 1996-2008 Scientific American Inc.

Keyword: Language; Vision
Link ID: 11680 - Posted: 06.24.2010

By Patrick Barry Macaque monkeys with electrodes implanted in their brains learned to control a robotic arm with their thoughts, researchers report. Scientists gently restrained the monkeys’ own arms and positioned the mechanical arm at each animal’s left shoulder as if it were a real arm. After practicing for several days, the monkeys appeared to treat the robotic arm as their own and could feed themselves with the arm using fluid, rapid motions. “The thing that struck me was how naturally the animals interacted with the device,” comments John Kalaska, a neuroscientist from the University of Montreal who wrote a commentary that appeared with the research online May 28 in Nature. “It’s a further proof of principle that, down the line, we will be able to develop all the hardware necessary to allow paraplegic or quadriplegic patients to have prosthetic limbs that they can control in a natural way with their thoughts.” Such devices for humans are still years away, Kalaska cautions. The computers that interpreted the monkeys’ brain signals in the current experiments are bulky, making them impractical for a portable prosthetic. And in past research, electrodes implanted into the brains of animals or humans lost contact with the nerve cells after months or weeks because cells in the brain treated the electrodes as foreign objects and attacked them. Both of these obstacles would have to be overcome before thought-controlled robotic arms or legs for people would be feasible, Kalaska says. © Society for Science & the Public 2000 - 2008

Keyword: Robotics
Link ID: 11679 - Posted: 06.24.2010