Most Recent Links

Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.

Links 41 - 60 of 21077

Angus Chen English bursts with consonants. We have words that string one after another, like angst, diphthong and catchphrase. But other languages keep more vowels and open sounds. And that variability might be because they evolved in different habitats. Consonant-heavy syllables don't carry very well in places like windy mountain ranges or dense rainforests, researchers say. "If you have a lot of tree cover, for example, [sound] will reflect off the surface of leaves and trunks. That will break up the coherence of the transmitted sound," says Ian Maddieson, a linguist at the University of New Mexico. That can be a real problem for complicated consonant-rich sounds like "spl" in "splice" because of the series of high-frequency noises. In this case, there's a hiss, a sudden stop and then a pop. Where a simple, steady vowel sound like "e" or "a" can cut through thick foliage or the cacophony of wildlife, these consonant-heavy sounds tend to get scrambled. Hot climates might wreck a word's coherence as well, since sunny days create pockets of warm air that can punch into a sound wave. "You disrupt the way it was originally produced, and it becomes much harder to recognize what sound it was," Maddieson says. "In a more open, temperate landscape, prairies in the Midwest of the United States [or in Georgia] for example, you wouldn't have that. So the sound would be transmitted with fewer modifications." © 2015 npr

Keyword: Language; Evolution
Link ID: 21616 - Posted: 11.07.2015

By Elahe Izadi The days growing shorter and colder can be more than just a nuisance; the seasonal change can also trigger clinical depression. Those who suffer from seasonal affective disorder, or SAD, may turn to a light box to help make them feel better. But a new study suggests another form of therapy could be more powerful and enduring: talking. The benefits of cognitive behavioral therapy — a form of talk therapy — outlasted light therapy sessions for people suffering from SAD, according to a study published Thursday in the American Journal of Psychiatry. "Light therapy is a treatment that suppresses symptoms as long as you're using it," said lead author Kelly Rohan, a psychology professor at the University of Vermont. "So if you're not using it, there's no reason to expect the continued benefit for a treatment that works that way, whereas cognitive behavioral therapy teaches skills." And the people who learn those skills can use them long after their therapy sessions. For the study, researchers tracked 177 people who suffer from major depression that follows a recurring seasonal pattern. About half of the subjects received six weeks of daily light therapy; the others received 12 sessions of cognitive behavioral therapy over the same period of time.

Keyword: Depression; Biological Rhythms
Link ID: 21615 - Posted: 11.07.2015

By Rachel E. Gross For decades, Michael Jackson had struggled to fall asleep at night. But in 2009 the pop singer was preparing for his worldwide comeback tour, and he couldn’t afford to be at anything less than 100 percent. Desperate for sleep, he convinced an unscrupulous physician to give it to him synthetically in the form of an anesthetic so strong that it sent him almost immediately into a “druglike coma.” At first, Jackson would wake up feeling refreshed. But the nightly injections conferred only the shadow of true sleep, with none of the deep, dream-filled REM cycles that his body needed. Soon he was fading fast, his mind and mood slipping away. Within two months Jackson was dead of an overdose. If that hadn’t killed him, doctors later testified during his wrongful death trial, he would have died of sleep deprivation. Jackson’s is a particularly dramatic case. But his struggle for oblivion rings true to anyone who has dealt with insomnia. “I’m for anything that gets you through the night,” Frank Sinatra once said, “be it prayer, tranquilizers, or a bottle of Jack Daniel’s.” If you have insomnia, you’ll understand this sentiment, and you’re not alone: Regular sleep eludes up to 15 percent of the population, making insomnia the most commonly diagnosed sleep problem in America. Fortunately, the nighttime affliction is becoming steadily less mysterious—at least from the perspective of neuroscience. While insomniacs toss and turn, researchers are finally starting to understand this elusive disease. As it turns out, chronic insomnia may be more hard-wired into our brains than we had thought, and indicative of larger differences that separate the brains of the sleepless from those who so effortlessly enter the land of dreams. © 2015 The Slate Group LLC

Keyword: Sleep
Link ID: 21614 - Posted: 11.07.2015

by Laura Sanders Babies’ minds are mysterious. Thoughts might be totally different in a brain that lacks words, and sensations might feel alien in a body so new. Are babies’ perceptions like ours, or are they completely different? Even if babies could talk, words would surely fail to convey what it’s like to experience, oh, every single thing for the first time. A recent paper offers a sliver of insight into young babies’ inner lives. The study, published October 19 in Current Biology, finds an example in which 4-month-old babies are happily oblivious to the external world. The research focuses on a perceptual trick that suckers adults and 6-month-old babies alike. When the hands are crossed, people often mistake which hand feels a touch. Let’s say your left hand (now crossed over to the right side of your body) gets a tickle. Your eyes would see a hand on the right side of your body get touched — a place usually claimed by your right hand, but now occupied by your left. Those mismatches between sight, touch and expectation can thwart you from quickly and correctly saying which hand was touched. Here’s the twist: 4-month-old babies don’t fall for this trick, Andrew Bremner of Goldsmiths, University of London and his colleagues found. In the experiment, a researcher would hold infants’ legs in either a crossed position or straight, while one of two remote-controlled buzzers taped to their feet tickled one foot. The researchers then watched which foot or leg wiggled as a result. If the buzzed foot moved, that meant that the baby got it right. © Society for Science & the Public 2000 - 2015.

Keyword: Development of the Brain; Pain & Touch
Link ID: 21613 - Posted: 11.07.2015

By Erika Beras From the backseat of a cab, the moves a driver makes may at times seem, let’s say, daring. In fact, cabbies may actually be better, more agile drivers than the rest of us. Because they know their streets so well. Previous research found that the hippocampus in the brain of a typical cab driver is enlarged. That’s the part of the brain used in navigation. But now a study confirms that learning detailed navigation information does indeed cause that part of the brain to grow. The findings are in the journal NeuroImage. Researchers had young adults who were not regular gamers play a driving simulation game. Some practiced maneuvering the same route 20 times, while other players were confronted with 20 different routes. The participants’ brains were scanned before they performed the simulated driving and again after. Researchers found that subjects who kept repeating the same route increased their speed more than those driving multiple routes. The single-route drivers were also much better able to put in order a sequence of random pictures taken along the way and to draw a map of the route. The investigators also found increases in the single-route drivers in the functional connectivity between the hippocampus and other parts of the brain involved with navigation. And the amount of change was directly related to the amount of improvement each participant displayed. © 2015 Scientific American

Keyword: Learning & Memory
Link ID: 21612 - Posted: 11.07.2015

By Kelli Whitlock Burton More than half of Americans over the age of 70 have cataracts, caused by clumps of proteins collecting in the eye lens. The only way to remove them is surgery, an unavailable or unaffordable option for many of the 20 million people worldwide who are blinded by the condition. Now, a new study in mice suggests eye drops made with a naturally occurring steroid could reverse cataracts by teasing apart the protein clumps. “This is a game changer in the treatment of cataracts,” says Roy Quinlan, a molecular biologist at Durham University in the United Kingdom who was not part of the study. “It takes decades for the cataracts to get to that point, so if you can reverse that by a few drops in the eye over a couple of weeks, that’s amazing.” The proteins that make up the human lens are among the oldest in the body, forming at about 4 weeks after fertilization. The majority are crystallins, a family of proteins that allow the eye to focus and keep the lens clear. Two of the most abundant crystallins, CRYAA and CRYAB, are produced in response to stress or injury. They act as chaperones, identifying and binding to damaged and misfolded proteins in the lens, preventing them from aggregating. But over the years, as damaged proteins accumulate in the lens, these chaperones become overwhelmed. The mutated proteins then clump together, blocking light and producing the tell-tale cloudiness of cataracts. © 2015 American Association for the Advancement of Science

Keyword: Vision
Link ID: 21611 - Posted: 11.06.2015

THINK twice before you tell that fib. By watching courtroom videos, a computer has learned to predict if someone is telling the truth or a lie. A machine learning algorithm trained on the faces of defendants in recordings of real trials, including that of Andrea Sneiderman (above) who was convicted of lying, correctly identified truth-tellers about 75 per cent of the time. Humans managed just 59.5 per cent. The best interrogators can reach 65 per cent. “We’re actually pretty bad lie detectors,” says Rada Mihalcea at the University of Michigan in Ann Arbor. Mihalcea and her colleagues took 121 videos from sources such as the Innocence Project, a non-profit group in Texas dedicated to exonerating people with wrongful convictions. This is superior to simulated conversation because the speakers are more invested in what they are saying. Transcriptions of the videos that included the speaker’s gestures and expressions were fed into a machine learning algorithm, along with the trial’s outcome. To hone it further, the team plans to feed in even more data. Such a system could one day spot liars in real-time in court or at airport customs, says Mihalcea, who will present the work at the International Conference on Multimodal Interaction this month in Seattle, Washington. © Copyright Reed Business Information Ltd.

Keyword: Emotions
Link ID: 21610 - Posted: 11.06.2015

Nancy Shute In September, we reported on a charming little study that found people who feel blue after watching sad videos have a harder time perceiving colors on the blue-yellow axis. Now the researchers may be feeling blue themselves. On Thursday they retracted their study, saying that errors in how they structured the experiment skewed the results. Shortly after the study was published online, commenters started looking skeptically at the results. And because the researchers had posted their data online, those commenters were able to run the numbers themselves. They didn't like what they found. As one blogger wrote: "A major problem is that the authors are claiming that they've found an interaction between video condition and color axis, but they haven't actually tested this interaction, they've just done a pair of independent t-tests and found different results." As the indefatigable crew at the Retraction Watch blog points out, it's not the first time scientists have messed this up. "This exact experimental oversight occurs all too often, according to a 2011 paper in Nature Neuroscience, which found that the same number of papers performed the procedure incorrectly as did it correctly." And there were other problems, too, such as not testing participants' color perception before the study. © 2015 npr

Keyword: Emotions; Vision
Link ID: 21609 - Posted: 11.06.2015

David Cyranoski A Chinese neuroscientist has been sacked after reporting he had used magnetic fields to control neurons and muscle cells in nematode worms (pictured), using a protein that senses magnetism. Tsinghua University in Beijing has sacked a neuroscientist embroiled in a dispute over work on a long-sought protein that can sense magnetic fields. The university has not given a specific reason for its dismissal, however, and the scientist involved, Zhang Sheng-jia, says that he will contest their action. In September, Zhang reported in the journal Science Bulletin1 that he could manipulate neurons in worms by applying a magnetic field — a process that uses a magnetic-sensing protein. But a biophysicist at neighbouring Peking University, Xie Can, who claims to have discovered the protein’s magnetic-sensing capacity and to have a paper detailing his research under review, complained that Zhang should not have published his paper before Xie’s own work appeared. Xie said that by publishing, Zhang violated an agreement that the pair had reached — although the two scientists tell different versions about the terms of their agreement, and have different explanations of how Zhang came to be working with the protein. © 2015 Nature Publishing Group

Keyword: Animal Migration
Link ID: 21608 - Posted: 11.06.2015

Paul Ibbotson and Michael Tomasello The natural world is full of wondrous adaptations such as camouflage, migration and echolocation. In one sense, the quintessentially human ability to use language is no more remarkable than these other talents. However, unlike these other adaptations, language seems to have evolved just once, in one out of 8.7 million species on earth today. The hunt is on to explain the foundations of this ability and what makes us different from other animals. The intellectual most closely associated with trying to pin down that capacity is Noam Chomsky. He proposed a universal grammatical blueprint that was unique to humans. This blueprint operated like a computer program. Instead of running Windows or Excel, this program performed “operations” on language – any language. Regardless of which of the 6000+ human languages that this code could be exposed to, it would guide the learner to the correct adult grammar. It was a bold claim: despite the surface variations we hear between Swahili, Japanese and Latin, they are all run on the same piece of underlying software. As ever, remarkable claims require remarkable evidence, and in the 50 years since some of these ideas were laid out, history has not been kind. First, it turned out that it is really difficult to state what is “in” universal grammar in a way that does justice to the sheer diversity of human languages. Second, it looks as if kids don’t learn language in the way predicted by a universal grammar; rather, they start with small pockets of reliable patterns in the language they hear, such as Where’s the X?, I wanna X, More X, It’s a X, I’m X-ing it, Put X here, Mommy’s X-ing it, Let’s X it, Throw X, X gone, I X-ed it, Sit on the X, Open X, X here, There’s a X, X broken … and gradually build their grammar on these patterns, from the “bottom up”. © 2015 Guardian News and Media Limited

Keyword: Language
Link ID: 21607 - Posted: 11.06.2015

Laura Sanders Specialized cells that make up the brain’s GPS system have an expanding job description. In addition to mapping locations, these cells can keep track of distance and time, too, scientists report in the Nov. 4 Neuron. Those specialized cells, called grid cells, were thought to have a very specific job, says neuroscientist Loren Frank of the University of California, San Francisco. But, he says, the new study says, “not so fast, everybody.” These cells’ ability to detect time and distance is unexpected. “And I think it’s important,” Frank says. The growing to-do list of grid cells shows that the brain’s navigational system is surprisingly flexible. The discovery of grid cells, found in a part of the brain called the entorhinal cortex, was recognized with the Nobel Prize last year (SN Online: 10/6/14). These brain cells fire off regular signals as animals move around in space, partially forming an internal map of the environment. Neuroscientist Howard Eichenbaum of Boston University and colleagues wondered what those cells do when an animal stays put. By training rats to run on a treadmill, the researchers had a way to study grid cells as time and distance marched forward, but location remained the same. Unlike recently discovered “speed cells” (SN: 8/8/15, p. 8), these grid cells don’t change their firing rates to correspond to changes in the rats’ swiftness, the researchers found. Instead, these cells stay tuned to distance or time, or both. © Society for Science & the Public 2000 - 2015.

Keyword: Learning & Memory
Link ID: 21606 - Posted: 11.05.2015

Natasha Gilbert The eye-catching plumage of some male songbirds has long been explained as a result of sexual selection: brighter males compete more successfully for mates, so evolution favours their spread. Females, by contrast, remain drab. A new study turns this explanation on its head. Sexual-selection pressures drive females to evolve dull feathers more strongly than they drive males to become colourful, argues James Dale, an evolutionary ecologist at Massey University in Auckland, New Zealand. That surprising conclusion is based on a data set of plumage colour in nearly 6,000 songbirds, which Dale and his colleagues built. They used their data to ask how various potential evolutionary factors drive male and female plumage colour. If a particular songbird species was polygynous (that is, the males had more than one mate), displayed a large difference in size between males and females, and left care of the young mainly up to the females, then the researchers judged that sexual selection was likely to be an important factor in that species' evolution. The study, published in Nature1, found that sexual selection does play an important role in creating colour differences between male and female plumage. But the contrast is largely driven by females evolving to become drab. “Females are the chief architect of the difference,” says Dale. © 2015 Nature Publishing Group

Keyword: Sexual Behavior; Evolution
Link ID: 21605 - Posted: 11.05.2015

Laura Sanders Blood tells a story about the body it inhabits. As it pumps through vessels, delivering nutrients and oxygen, the ruby red liquid picks up information. Hormones carried by blood can hint at how hungry a person is, or how scared, or how sleepy. Other messages in the blood can warn of heart disease or announce a pregnancy. When it comes to the brain, blood also seems to be more than a traveling storyteller. In some cases, the blood may be writing the script. A well-fed brain is crucial to survival. Blood ebbs and flows within the brain, moving into active areas in response to the brain’s demands for fuel. Now scientists have found clues that blood may have an even more direct and powerful influence. Early experiments suggest that, instead of being at the beck and call of nerve cells, blood can actually control them. This role reversal hints at an underappreciated layer of complexity — a layer that may turn out to be vital to how the brain works. The give-and-take between brain and blood appears to change with age and with illness, researchers are finding. Just as babies aren’t born walking, their developing brain cells have to learn how to call for blood. And a range of age-related disorders, including Alzheimer’s disease, have been linked to dropped calls between blood and brain, a silence that may leave patches of brain unable to do their jobs. © Society for Science & the Public 2000 - 2015

Keyword: Brain imaging
Link ID: 21604 - Posted: 11.05.2015

Doubts are emerging about one of our leading models of consciousness. It seems that brain signals thought to reflect consciousness are also generated during unconscious activity. A decade of studies have lent credence to the global neuronal workspace theory of consciousness, which states that when something is perceived unconsciously, or subliminally, that information is processed locally in the brain. In contrast, conscious perception occurs when the information is broadcast to a “global workspace”, or assemblies of neurons distributed across various brain regions, leading to activity over the entire network. Proponents of this idea, Stanislas Dehaene at France’s national institute for health in Gif-sur-Yvette, and his colleagues, discovered that when volunteers view stimuli that either enter conscious awareness or don’t, their brains show identical EEG activity for the first 270 milliseconds. Then, if perception of the stimuli is subliminal, the brain activity peters out. However, when volunteers become conscious of the stimuli, there is a sudden burst of widespread brain activity 300 ms after the stimulus. This activity is characterised by an EEG signal called P3b, and has been called a neural correlate of consciousness. Brian Silverstein and Michael Snodgrass at the University of Michigan in Ann Arbor, and colleagues wondered if P3b could be detected during unconscious processing of stimuli. © Copyright Reed Business Information Ltd.

Keyword: Consciousness
Link ID: 21603 - Posted: 11.05.2015

By Nicholas Bakalar A person with depression is at higher risk for heart disease, and a person with heart disease is at higher risk for depression. The link between the two diseases is complex and not entirely understood. Many of the effects of depression — feeling unable to exercise or eat properly, for example — and the behaviors associated with depression, like smoking and abusing alcohol, are well established risk factors for heart disease. Some studies have suggested that insomnia, another symptom of depression, may also increase the risk for cardiovascular illness. Depression can also make heart disease worse. Heart patients with depression may find it more difficult to take medications and comply with the behavioral demands of living with heart disease. Depression may also have destructive physiological effects on heart rhythm, blood pressure, stress hormone levels and blood clotting, studies have shown. These may be among the reasons why depressed patients with stable cardiovascular disease, or those who have survived a heart attack or had coronary bypass surgery, are at two to three times higher risk of dying than similar patients without depression. Treating depressed heart patients with drugs like Prozac may help. These drugs, known as selective serotonin reuptake inhibitors, or S.S.R.I.’s, in addition to relieving depression, have blood-thinning effects that may be beneficial against heart disease. “It is clear that treatment with an S.S.R.I. reduces cardiac mortality in depressed patients post heart attack,” said Dr. Steven P. Roose, a professor of psychiatry at Columbia. “What is not clear is whether the reduction in mortality results from the antidepressant effect of the medication or the anti-platelet effect of the medication.” © 2015 The New York Times Company

Keyword: Depression; Neuroimmunology
Link ID: 21602 - Posted: 11.05.2015

By DAVE ITZKOFF and BENEDICT CAREY For the first time in more than a year, the widow of the actor Robin Williams is speaking publicly about the circumstances that preceded Mr. Williams’s death, and sharing details about a disease he had when he died. Stories from Our Advertisers In interviews with People magazine and with ABC News, the widow, Susan Schneider Williams, laid the blame for her husband’s suicide in 2014 not on depression but on diffuse Lewy body dementia. “It was not depression that killed Robin,” Mrs. Williams said in the People magazine interview. “Depression was one of let’s call it 50 symptoms and it was a small one.” She added: “This was a very unique case and I pray to God that it will shed some light on Lewy bodies for the millions of people and their loved ones who are suffering with it. Because we didn’t know. He didn’t know.” Parts of an interview with Mrs. Williams were shown Tuesday on ABC’s “Good Morning America,” with further segments scheduled for that evening on the network’s “World News Tonight” and “Nightline” programs, and Friday on its morning talk show “The View.” Robin Williams was one of the most explosively, exhaustingly, prodigiously verbal comedians who ever lived, says film critic A. O. Scott. And the only thing faster than Williams’s mouth was his mind. By Adam Freelander on Publish Date August 12, 2014. Photo by ABC, via Associated Press. Watch in Times Video » Mr. Williams, the stand-up comic and star of “Mork & Mindy,” “Good Morning, Vietnam,” “Good Will Hunting” (for which he won an Oscar) and “Dead Poets Society,” killed himself on Aug. 11, 2014, in the home he shared with Mrs. Williams in Tiburon, Calif. He was 63. © 2015 The New York Times Company

Keyword: Alzheimers; Depression
Link ID: 21601 - Posted: 11.04.2015

Sara Reardon Military-service members can suffer brain injury and memory loss when exposed to explosions in enclosed spaces, even if they do not sustain overt physical injury. A strategy designed to improve memory by delivering brain stimulation through implanted electrodes is undergoing trials in humans. The US military, which is funding the research, hopes that the approach might help many of the thousands of soldiers who have developed deficits to their long-term memory as a result of head trauma. At the Society for Neuroscience meeting in Chicago, Illinois, on 17–21 October, two teams funded by the Defense Advanced Research Projects Agency presented evidence that such implanted devices can improve a person’s ability to retain memories. By mimicking the electrical patterns that create and store memories, the researchers found that gaps caused by brain injury can be bridged. The findings raise hopes that a ‘neuro­prosthetic’ that automatically enhances flagging memory could aid not only brain-injured soldiers, but also people who have had strokes — or even those who have lost some power of recall through normal ageing. Because of the risks associated with surgically placing devices in the brain, both groups are studying people with epilepsy who already have implanted electrodes. The researchers can use these electrodes both to record brain activity and to stimulate specific groups of neurons. Although the ultimate goal is to treat traumatic brain injury, these people might benefit as well, says biological engineer Theodore Berger at the University of Southern California (USC) in Los Angeles. That is because repeated seizures can destroy the brain tissue needed for long-term-memory formation. © 2015 Nature Publishing Group

Keyword: Learning & Memory; Robotics
Link ID: 21600 - Posted: 11.04.2015

Your sense of smell might be more important than you think. It could indicate how well your immune system is functioning, a study in mice suggests. Evidence of a connection between the immune system and the olfactory system – used for sense of smell – has been building for some time. For instance, women seem to prefer the scent of men with different immune system genes to their own. Meanwhile, other studies have hinted that the robustness of your immune system may influence how extraverted you are. To investigate further, Fulvio D’Acquisto at Queen Mary University of London and his colleagues studied mice missing a recombinant activating gene (RAG), which controls the development of immune cells. Without it, mice lack a working immune system and some genes are expressed differently, including those involved in the olfactory system. “That rang bells, because people with immune deficiencies often lose their sense of smell,” says D’Acquisto. Systemic lupus erythematosus, an autoimmune disease in which the immune system mistakenly attacks tissues in the skin, joints, kidneys, brain, and other organs, is one such example. His team measured how long it took mice to find chocolate chip cookies buried in their cages. Those missing RAG took five times as long as normal mice. They also failed to respond to the scent of almond or banana, which mice usually find very appealing – although they did still react to the scent of other mice. Further study uncovered abnormalities in the lining of their noses; physical evidence that their sense of smell might be disrupted. © Copyright Reed Business Information Ltd.

Keyword: Chemical Senses (Smell & Taste); Neuroimmunology
Link ID: 21599 - Posted: 11.04.2015

Scientists have come up with a questionnaire they say should help diagnose a condition called face blindness. Prosopagnosia, as doctors call it, affects around two in every 100 people in the UK and is the inability to recognise people by their faces alone. In its most extreme form, people cannot even recognise their family or friends. Milder forms, while still distressing, can be tricky to diagnose, which is why tests are needed. People with prosopagnosia often use non-facial cues to recognise others, such as their hairstyle, clothes, voice, or distinctive features. Some may be unaware they have the condition, instead believing they have a "bad memory for faces". But prosopagnosia is entirely unrelated to intelligence or broader memory ability. One [anonymous] person with prosopagnosia explains: "My biggest problem is seeing the difference between ordinary-looking people, especially faces with few specific traits. "I work at a hospital with an awful lot of employees and I often introduce myself to colleagues with whom I have worked several times before. I also often have problems recognising my next-door neighbour, even though we have been neighbours for eight years now. She often changes clothes, hairstyle and hair colour. When I strive to recognise people, I try to use technical clues like clothing, hairstyle, scars, glasses, their dialect and so on." Doctors can use computer-based tests to see if people can spot famous faces and memorise and recognise a set of unfamiliar faces. And now Drs Richard Cook, Punit Shah and City University London and Kings College London have come up with a 20-item questionnaire to help measure the severity of someone's face blindness. © 2015 BBC

Keyword: Attention
Link ID: 21598 - Posted: 11.04.2015

By Christof Koch Artificial intelligence has been much in the news lately, driven by ever cheaper computer processing power that has become effectively a near universal commodity. The excitement swirls around mathematical abstractions called deep convolutional neural networks, or ConvNets. Applied to photographs and other images, the algorithms that implement ConvNets identify individuals from their faces, classify objects into one of 1,000 distinct categories (cheetah, husky, strawberry, catamaran, and so on)—and can describe whether they see “two pizzas sitting on top of a stove top oven” or “a red motorcycle parked on the side of the road.” All of this happens without human intervention. Researchers looking under the hood of these powerful algorithms are surprised, puzzled and entranced by the beauty of what they find. How do ConvNets work? Conceptually they are but one or two generations removed from the artificial neural networks developed by engineers and learning theorists in the 1980s and early 1990s. These, in turn, are abstracted from the circuits neuroscientists discovered in the visual system of laboratory animals. Already in the 1950s a few pioneers had found cells in the retinas of frogs that responded vigorously to small, dark spots moving on a stationary background, the famed “bug detectors.” Recording from the part of the brain's outer surface that receives visual information, the primary visual cortex, Torsten Wiesel and the late David H. Hubel, both then at Harvard University, found in the early 1960s a set of neurons they called “simple” cells. These neurons responded to a dark or a light bar of a particular orientation in a specific region of the visual field of the animal. © 2015 Scientific American

Keyword: Vision; Robotics
Link ID: 21597 - Posted: 11.03.2015