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By Hannah Tepper These days, we seem to be living in a new golden age of choice. One moment we’re tweeting, the next we are changing our profile picture. We get a hankering for hummus and next thing we know, it’s off to Yelp the nearest falafel place. In every choice and action we make, online or off, we have the unique sense that we are in control. This is what it feels like to have free will. But many neuroscientists have maintained a long-standing opinion that what we experience as free will is no more than mechanistic patterns of neurons firing in the brain. Although we feel like free agents contemplating and choosing, they would argue that these sensations are merely an emotional remnant that brain activity leaves in its wake. If these neuroscientists are right, then free will isn’t worth much discussion. Michael S. Gazzaniga, professor and director of the SAGE Center for the Study of the Mind at the University of California at Santa Barbara, seriously disagrees. In his new book out this month, “Who’s In Charge: Free Will and the Science of the Brain,“ Gazzaniga uses a lifetime of experience in neuroscientific research to argue that free will is alive and well. Instead of reducing free will to the sum of its neurological parts, he argues that it’s time for neuroscience to consider free will as a scientific fact in its own right. Through fascinating examples in chaos theory, physics, philosophy and, of course, neuroscience, Gazzaniga makes this interesting claim: Just as you cannot explain traffic patterns by studying car parts, neuroscience must abandon its tendency to reduce macro-level phenomena like free will to micro-level explanations. Along the way he provides fascinating and understandable information from brain evolution to studies involving infants and patients with severed brain hemispheres (split-brain patients). The final chapters of the book consider neuroscience as it implicates social responsibility, justice and how we treat criminal offense. © 2011 Salon Media Group, Inc.
By RAYMOND TALLIS The world of academe is currently in the grip of a strange and worrying ¬epidemic of biologism, which has also captured the popular imagination. Scientists, philosophers and quite a few toilers in the humanities believe—and would have the rest of us believe—that nothing fundamental separates humanity from animality. Biologism has two cardinal manifestations. One is the claim that the mind is the brain, or the activity of the brain, so that one of the most powerful ways to advance our understanding of ourselves is to look at our brains in action, using the latest scanning devices. The other is the claim that Darwinism explains not only how the organism Homo sapiens came into being (as, of course, it does) but also what motivates people and shapes their day-to-day behavior. These beliefs are closely connected. If the brain is an evolved organ, shaped by natural selection to ensure evolutionary success (as it most surely is), and if the mind is the brain and nothing more, then the mind and all those things we are minded to do can be explained by the evolutionary imperative. The mind is a cluster of apps or modules securing the replication of the genes that are expressed in our bodies. Many in the humanities have embraced these views with astonishing fervor. New disciplines, prefixed by "neuro" or "evolutionary" or even "neuro-evolutionary," have been invented. "Neuro-aesthetics" explains aesthetic pleasure in terms of activity in certain parts of the brain observed when people are enjoying works of art. A propensity for aesthetic brain-tingles, implanted in us by evolution, causes us to tingle to the right kinds of things, such as pictures of landscapes loaded with food. ©2011 Dow Jones & Company, Inc.
by Chelsea Whyte Signs of consciousness have been detected in three people previously thought to be in a vegetative state, with the help of a cheap, portable device that can be used at the bedside. "There's a man here who technically meets all the internationally agreed criteria for being in a vegetative state, yet he can generate 200 responses [to direct commands] with his brain," says Adrian Owen of the University of Western Ontario. "Clearly this guy is not in a true vegetative state. He's probably as conscious as you or I are." In 2005, Owen's team, used functional MRI to show consciousness in a person who was in a persistent vegetative state, also known as wakeful unconsciousness – where the body still functions but the mind is unresponsive – for the first time. However, fMRI is costly and time-consuming, so his team set about searching for simple and cost-effective solutions for making bedside diagnoses of PVS. Now, they have devised a test that uses the relatively inexpensive and widely available electroencephalogram (EEG). Owen and his team used an EEG on 16 people thought to be in a PVS and compared the results with 12 healthy controls while they were asked to imagine performing a series of tasks. Each person was asked to imagine at least four separate actions – either clenching their right fist or wiggling their toes. Journal reference: The Lancet, DOI:10.1016/S0140-6736(11)61224-5 © Copyright Reed Business Information Ltd.
By Bruce Bower SEATTLE — Good listeners inadvertently turn a deaf ear to unexpected sounds. Attending closely to a conversation creates a situation in which unusual, clearly audible background utterances frequently go totally unheard, says psychologist Polly Dalton of the University of London. This finding takes the famous “invisible gorilla effect” from vision into the realm of hearing, Dalton reported November 4 at the annual meeting of the Psychonomic Society. More than a decade ago, researchers observed that about half of volunteers watching a videotape of people passing a basketball fail to see a gorilla-suited person walking through the group if the viewers are instructed to focus on counting how many times the ball gets passed (SN: 5/21/11, p. 16). An ability to prioritize what sounds and sights to monitor supports daily activities, but it can also wipe out perceptions of obvious peripheral happenings. “We’re not aware of as much in the world as we think we are,” Dalton said. Dalton and her colleagues created a 69-second recording of two men talking as they prepared food for a party and two women chatting as they wrapped a party gift. Headphones delivered one conversation to each ear of 41 volunteers, creating a sense of the four characters moving around a room as they talked. Partway into the recording, a man dubbed “gorilla man” by the researchers appears in the acoustic scene for 19 seconds saying “I’m a gorilla” over and over. Participants were assigned to pay attention either to the men’s or the women’s conversation. © Society for Science & the Public 2000 - 2011
Related chapters from BP6e: Chapter 18: Attention and Higher Cognition; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 16009 - Posted: 11.08.2011
Megan Erickson The simplest description of a black hole is a region of space-time from which no light is reflected and nothing escapes. The simplest description of consciousness is a mind that absorbs many things and attends to a few of them. Neither of these concepts can be captured quantitatively. Together they suggest the appealing possibility that endlessness surrounds us and infinity is within. But our inability to grasp the immaterial means we’re stuck making inferences, free-associating, if we want any insight into the unknown. Which is why we talk obscurely and metaphorically about "pinning down" perception and “hunting for dark matter” (possibly a sort of primordial black hole). The existence of black holes was first hypothesized a decade after Einstein laid the theoretical groundwork for them in the theory of relativity, and the phrase "black hole" was not coined until 1968. Likewise, consciousness is still such an elusive concept that, in spite of the recent invention of functional imaging - which has allowed scientists to visualize the different areas of the brain - we may not understand it any better now than we ever have before. “We approach [consciousness] now perhaps differently than we have in the past with our new tools," says neuroscientist Joy Hirsch. "The questions [we ask] have become a little bit more sophisticated and we’ve become more sophisticated in how we ask the question," she adds - but we're still far from being able to explain how the regions of the brain interact to produce thought, dreams, and self-awareness. “In terms of understanding, the awareness that comes from binding remote activities of the brain together, still remains what philosophers call, ‘The hard problem.'"
Sharon Begley Like many colleges, Washington University in St. Louis offers children of its faculty free tuition. So Leonard Green, a professor of psychology there, did all he could to persuade his daughter to choose the school. He extolled its academic offerings, praised its social atmosphere, talked up its extracurricular activities—and promised that if Hannah chose Washington he would give her $20,000 each undergraduate year, plus $20,000 at graduation, for a nest egg totaling $100,000. She went to New York University. To many, this might seem like a simple case of shortsightedness, a decision based on today’s wants (an exciting city, independence) versus tomorrow’s needs (money, shelter). Indeed, the choice to spend rather than save reflects a very human—and, some would say, American—quirk: a preference for immediate gratification over future gains. In other words, we get far more joy from buying a new pair of shoes today, or a Caribbean vacation, or an iPhone 4S, than from imagining a comfortable life tomorrow. Throw in an instant-access culture—in which we can get answers on the Internet within seconds, have a coffeepot delivered to our door overnight, and watch movies on demand—and we’re not exactly training the next generation to delay gratification. “Pleasure now is worth more to us than pleasure later,” says economist William Dickens of Northeastern University. “We much prefer current consumption to future consumption. It may even be wired into us.” © 2011 The Newsweek/Daily Beast Company LLC
Related chapters from BP6e: Chapter 18: Attention and Higher Cognition; Chapter 4: The Chemical Bases of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 15984 - Posted: 11.05.2011
by Andy Coghlan Not all brain regions are created equal – instead, a "rich club" of 12 well-connected hubs orchestrates everything that goes on between your ears. This elite cabal could be what gives us consciousness, and might be involved in disorders such as schizophrenia and Alzheimer's disease. As part of an ongoing effort to map the human "connectome" – the full network of connections in the brain – Martijn van den Heuvel of the University Medical Center in Utrecht, the Netherlands, and Olaf Sporns of Indiana University Bloomington scanned the brains of 21 people as they rested for 30 minutes. The researchers used a technique called diffusion tensor imaging to track the movements of water through 82 separate areas of the brain and their interconnecting neurons. They found 12 areas of the brain had significantly more connections than all the others, both to other regions and among themselves. "These 12 regions have twice the connections of other brain regions, and they're more strongly connected to each other than to other regions," says Van den Heuvel. "If we wanted to look for consciousness in the brain, I would bet on it turning out to be this rich club," he adds. The elite group consists of six pairs of identical regions, with one of each pair in each hemisphere of the brain. Each member is known to accept only preprocessed, high-order information, rather than raw incoming sensory data. © Copyright Reed Business Information Ltd.
Related chapters from BP6e: Chapter 18: Attention and Higher Cognition; Chapter 4: The Chemical Bases of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 15974 - Posted: 11.03.2011
by David Eagleman Only a tiny fraction of the brain is dedicated to conscious behavior. The rest works feverishly behind the scenes regulating everything from breathing to mate selection. In fact, neuroscientist David Eagleman of Baylor College of Medicine argues that the unconscious workings of the brain are so crucial to everyday functioning that their influence often trumps conscious thought. To prove it, he explores little-known historical episodes, the latest psychological research, and enduring medical mysteries, revealing the bizarre and often inexplicable mechanisms underlying daily life. Eagleman’s theory is epitomized by the deathbed confession of the 19th-century mathematician James Clerk Maxwell, who developed fundamental equations unifying electricity and magnetism. Maxwell declared that “something within him” had made the discoveries; he actually had no idea how he’d achieved his great insights. It is easy to take credit after an idea strikes you, but in fact, neurons in your brain secretly perform an enormous amount of work before inspiration hits. The brain, Eagleman argues, runs its show incognito. Or, as Pink Floyd put it, “There’s someone in my head, but it’s not me.” There is a looming chasm between what your brain knows and what your mind is capable of accessing. Consider the simple act of changing lanes while driving a car. Try this: Close your eyes, grip an imaginary steering wheel, and go through the motions of a lane change. Imagine that you are driving in the left lane and you would like to move over to the right lane. Before reading on, actually try it. I’ll give you 100 points if you can do it correctly. © 2011, Kalmbach Publishing Co.
by Jessica Hamzelou HUMAN minds wander when they have nothing else to do. This is when people start to introspect, using a specific network of brain structures. The same network has now been identified in monkeys and rats, suggesting that "zoning out" might serve a key function in our survival. The findings raise questions over whether lower animals might also be capable of something akin to introspection. The default mode network (DMN) is one of about 10 networks of brain regions that are active when a person is at rest. What makes the DMN interesting is that it becomes active when a person is asked to let their mind wander, but the network's activity drops away completely as soon as that person is given an external task. This suggests that, in humans at least, the DMN is involved in self-reflection and introspective thought processing. Building on recent evidence that anaesthetised monkeys might have a similar network, Wim Vanduffel and his colleagues at the Catholic University of Leuven (KUL) in Belgium collected a host of data from 15 studies which imaged the brain activity of 10 awake monkeys. By looking at the baseline brain activity measured in each project, the group was able to spot a network of brain structures that were active when the monkeys were not engaged in a task. This network looked strikingly similar to the human DMN (Journal of Neuroscience, DOI: 10.1523/jneurosci.2318-11.2011). © Copyright Reed Business Information Ltd.
by Linda Geddes MONKSEATON High School in Tyneside, UK, has seen some amazing improvements in the past year. Absenteeism is down, punctuality is up and exam results have gone through the roof. Head teacher Paul Kelley cannot attribute these successes to better teaching or stricter discipline. Instead, he simply started opening the school at 10 am instead of 9 am. The change was designed to synchronise the school day with pupils' body clocks. Teenagers are notoriously owlish, preferring to stay up into the small hours and sleep in till lunchtime. This isn't entirely their own fault: natural delays in secretion of the sleep hormone melatonin causes their body clocks to be shifted several hours backwards (New Scientist, 2 September 2006, p 40). By aligning the school day with these biological rhythms, Monkseaton school avoids teaching teenagers when their brains are still half asleep. In the modern world our lives are largely dictated by time. But even in the absence of clocks, schedules and calendars, our bodies still march to the beat of internal timekeepers called circadian rhythms. Over each 24-hour period we experience cycles of physical and mental changes that are thought to prepare our brains and bodies for the tasks we're likely to encounter at certain times of the day. The most obvious is the sleep-wake cycle, but there are many others. Circadian rhythms affect everything from how we perform on physical and mental tasks to when drugs are more likely to be effective. "We're not the same organism at midday and midnight," says Russell Foster, who researches circadian rhythms at the University of Oxford. © Copyright Reed Business Information Ltd.
by Sara Reardon Snuffling around in a Plexiglas box that it knows well, a black and white rat catches a whiff of chocolate cookies. It scampers toward them—but suddenly, it finds itself teleported into another, equally familiar box. One could hardly blame the poor rat for being confused and disoriented for at least a fraction of a second, and researchers have now figured out why: cells in the memory center of its brain compete over where it is for exactly one-eighth of a second. The "teleportation" effect in rats is similar to the momentary disorientation you feel when elevator doors open and you step out onto the wrong floor. It occurs because the place you expect to see and the place you actually do are "mutually exclusive," says Edvard Moser, a neuroscientist at the Norwegian University of Science and Technology in Trondheim. Normally, the brain orients itself gradually as you move. The hippocampus, the brain's memory center, contains neurons known as place cells, which record both your environment and your movement within it in order to form memories that ensure you always know where you are. To update the brain on your position, place cells fire in a rhythm called a theta oscillation, which repeats itself every 125 milliseconds and is especially prominent when you're moving. To teleport rats, Edvard Moser and his wife, neuroscientist May-Britt Moser, built two rat boxes connected by a tunnel. One box had a circle of white light-emitting diodes shining up through the clear floor, and the other had a row of green LEDs around the ceiling. The researchers let a rat run back and forth between the two boxes and forage for food until it became familiar with both. They also implanted an electrode array into the rat's hippocampus and recorded firing patterns from individual neurons while the rat was in each box. © 2010 American Association for the Advancement of Science
By Laura Sanders Humans live in a world of uncertainty. A shadowy figure on the sidewalk ahead could be a friend or a mugger. By flooring your car’s accelerator, you might beat the train to the intersection, or maybe not. Last week’s leftover kung pao chicken could bring another night of gustatory delight or gut agony. People’s paltry senses can’t always capture what’s real. Luckily, though, the human brain is pretty good at playing the odds. Thanks to the brain’s intuitive grasp of probabilities, it can handle imperfect information with aplomb. “Instead of trying to come up with an answer to a question, the brain tries to come up with a probability that a particular answer is correct,” says Alexandre Pouget of the University of Rochester in New York and the University of Geneva in Switzerland. The range of possible outcomes then guides the body’s actions. A probability-based brain offers a huge advantage in an uncertain world. In mere seconds, the brain can solve (or at least offer a good guess for) a problem that would take a computer an eternity to figure out — such as whether to greet the approaching stranger with pepper spray or a hug. A growing number of studies are illuminating how this certitude-eschewing approach works, and how powerful it can be. Principles of probability, researchers are finding, may guide basic visual abilities, such as estimating the tilt of lines or finding targets hidden amid distractions. Other behaviors, and even simple math, may depend on similar number crunching, some scientists think. © Society for Science & the Public 2000 - 2011
Related chapters from BP6e: Chapter 17: Learning and Memory; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 11: Emotions, Aggression, and Stress
Link ID: 15831 - Posted: 09.24.2011
By Bruce Bower For an instant identity crisis, just peruse some photographs of a stranger’s face. In many instances, people view different mug shots of an unfamiliar person as entirely different individuals, say psychologist Rob Jenkins of the University of Glasgow, Scotland, and his colleagues. Yet photos of a celebrity or other recognizable person retain a uniform identity despite changes in lighting, facial expression and other factors across images, the scientists report in a paper published online September 3 in Cognition. To better understand issues such as eyewitness memory, and with an eye on creating reliable facial-recognition software, psychologists, vision researchers and computer scientists are studying how people recognize faces of individuals they’ve just seen and faces of those they’ve encountered over many years. These studies typically examine whether volunteers recognize an image of a person’s face and distinguish it from individual shots of other faces. Variability in photos of the same face has gone largely unexplored, but the issue could pose problems, researchers say. “A complete theory of face recognition should explain not only how we tell people apart, but also how we tell people together,” Jenkins’ team concludes. A strong tendency to see different people in different images of the same face raises questions about whether passports and other photo IDs provide reliable proof of identity, the researchers contend. © Society for Science & the Public 2000 - 2011
Four-year-olds who watched nine minutes of the fast-paced cartoon SpongeBob Squarepants showed temporary attention and learning problems, researchers found. The study compared 60 children who were randomly assigned to watch SpongeBob, the slower-paced PBS cartoon Caillou or to draw pictures as a control. After nine minutes, the children did four tests to tap their "executive function" — such as attention, problem-solving and delay of gratification — which allows people to set goals and implement them. Executive function is important for helping children to learn and function in school and be creative, the researchers said. "Just nine minutes of viewing a fast-paced television cartoon had immediate negative effects on four-year-olds’ executive function," Angeline Lillard and Jennifer Peterson of the psychology department at the University of Virginia concluded in Monday's issue of the journal Pediatrics. "Parents should be aware that fast-paced television shows could at least temporarily impair young children’s executive function." In the fast-paced show, the scenes changed, for example, from a swimming pool to a bedroom, every 11 seconds on average compared with every 34 seconds on average in the educational TV show, the researchers said. The children also watched for nine minutes, while many cartoons last 11 minutes. Two such episodes are often shown in a 30-minute programming slot, Lillard and Peterson noted in suggesting that watching a full fast-paced program could be more harmful. © CBC 2011
By Laura Sanders To one part of the brain, a bathroom equals toilet plus tub. In mental terms, certain scenes are sums of their objects, researchers report online September 4 in Nature Neuroscience. The results help explain how people quickly and accurately recognize complicated scenes such as playgrounds, kitchens and traffic intersections. Much of what scientists know about vision comes from studies of how people see simple objects in isolation, such as a line floating on a white screen, says cognitive neuroscientist Dirk Bernhardt-Walther of Ohio State University. The new work, in contrast, deals with messy, real-world scenes. “It’s an awesome study,” he says. A number of different brain areas are involved in telling us where we are, each relying on different types of information. In cases where the general outlines of a place offer little information, it appears, the brain homes in on specific objects within that space. “A bathroom and a kitchen may have similar three-dimensional shapes of the interior, but the objects will tell you a big difference,” says study coauthor Sean MacEvoy of Boston College. MacEvoy and Russell Epstein of the University of Pennsylvania measured the brain activity of 28 people viewing one of four scenes: a bathroom, kitchen, street intersection or playground. Participants then saw isolated objects associated with each scene, allowing the researchers to record the neural signature of each object. MacEvoy and Epstein focused on a particular part of the brain called the lateral occipital cortex, or LOC, which had responded to objects in previous studies. © Society for Science & the Public 2000 - 2011
by Mark Buchanan The fuzziness and weird logic of the way particles behave applies surprisingly well to how humans think THE quantum world defies the rules of ordinary logic. Particles routinely occupy two or more places at the same time and don't even have well-defined properties until they are measured. It's all strange, yet true - quantum theory is the most accurate scientific theory ever tested and its mathematics is perfectly suited to the weirdness of the atomic world. Yet that mathematics actually stands on its own, quite independent of the theory. Indeed, much of it was invented well before quantum theory even existed, notably by German mathematician David Hilbert. Now, it's beginning to look as if it might apply to a lot more than just quantum physics, and quite possibly even to the way people think. Human thinking, as many of us know, often fails to respect the principles of classical logic. We make systematic errors when reasoning with probabilities, for example. Physicist Diederik Aerts of the Free University of Brussels, Belgium, has shown that these errors actually make sense within a wider logic based on quantum mathematics. The same logic also seems to fit naturally with how people link concepts together, often on the basis of loose associations and blurred boundaries. That means search algorithms based on quantum logic could uncover meanings in masses of text more efficiently than classical algorithms. © Copyright Reed Business Information Ltd.
Related chapters from BP6e: Chapter 18: Attention and Higher Cognition; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 11: Emotions, Aggression, and Stress
Link ID: 15769 - Posted: 09.06.2011
Kerri Smith The experiment helped to change John-Dylan Haynes's outlook on life. In 2007, Haynes, a neuroscientist at the Bernstein Center for Computational Neuroscience in Berlin, put people into a brain scanner in which a display screen flashed a succession of random letters1. He told them to press a button with either their right or left index fingers whenever they felt the urge, and to remember the letter that was showing on the screen when they made the decision. The experiment used functional magnetic resonance imaging (fMRI) to reveal brain activity in real time as the volunteers chose to use their right or left hands. The results were quite a surprise. "The first thought we had was 'we have to check if this is real'," says Haynes. "We came up with more sanity checks than I've ever seen in any other study before." The conscious decision to push the button was made about a second before the actual act, but the team discovered that a pattern of brain activity seemed to predict that decision by as many as seven seconds. Long before the subjects were even aware of making a choice, it seems, their brains had already decided. As humans, we like to think that our decisions are under our conscious control — that we have free will. Philosophers have debated that concept for centuries, and now Haynes and other experimental neuroscientists are raising a new challenge. They argue that consciousness of a decision may be a mere biochemical afterthought, with no influence whatsoever on a person's actions. According to this logic, they say, free will is an illusion. "We feel we choose, but we don't," says Patrick Haggard, a neuroscientist at University College London. © 2011 Nature Publishing Group,
By Jennifer Viegas Years of either running from or running after animals left its mark in the human brain -- even just looking at a photo of an animal jolts our brains into action. No matter how high tech and urban we may become, animals continue to affect our brains like no other person, place or thing, shows new research in the latest issue of Nature Neuroscience. Co-author Ralph Adolphs explained to Discovery News "that it is important for the brain to be able to rapidly detect animals. The reasons for this are probably several, but would likely include the need to avoid predators and catch prey." "These abilities are at once critically important to survival and yet very difficult to do," added Adolphs, a professor of psychology, neuroscience and biology at the California Institute of Technology. "Both predator and prey detection requires fast, real-time detection of shapes that are often camouflaged in a cluttered environment." Adolphs, project leader Florian Mormann, and their colleagues recorded how the brains of 41 neurosurgical patients undergoing epilepsy monitoring responded to images of people, landmarks, animals, or objects. During 111 experimental sessions, the researchers monitored the subjects' brain activity as they sat in bed while viewing about 100 images per session. The monitoring was quite precise, showing how even individual neurons reacted. athletes © 2011 Discovery Communications, LLC
Related chapters from BP6e: Chapter 18: Attention and Higher Cognition; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 15743 - Posted: 08.30.2011
by Elizabeth Norton Time is what keeps everything from happening at once, the American theoretical physicist John Wheeler once said. In the mind, as in the outside world, the flow of events contains individual experiences strung together in sequence yet separated by gaps in time. New research shows that during these gaps, neurons in a part of the brain called the hippocampus encode each "empty" moment as precisely as the surrounding events, allowing the brain to make detailed representations of time. The hippocampus has long been known as a center for navigation and memory. Research into this sea horse-shaped structure shows the importance of "place cells," groups of which fire when a person or animal is at a certain location. The firing pattern provides the neural basis of the mental maps used to find one's way around. But the hippocampus also encodes "episodic" memories of events as they occur in time. Thus, many researchers wondered whether the hippocampus also contains "time cells." To test the idea, Howard Eichenbaum and colleagues at Boston University trained rats to perform a two-part task with a delay in the middle while fitted with surgically implanted electrodes that recorded neural activity in the hippocampus. The rats were taught to associate an object with an odor: a ball with oregano, for example, and a cube with cinnamon. Then they were presented with one of the objects, after which they entered a chamber for 10 seconds. After this delay, a partition opened, leading to a flowerpot full of scented sand. If the scent paired with the object seen earlier, the rats knew to dig for a food reward. If the odor and object didn't match, the rats refrained from digging. (This correct response was rewarded with a treat in another part of the run.) © 2010 American Association for the Advancement of Science
Analysis by Marianne English There's more to picking up math concepts than paying attention in class, according to recent research. It turns out kids' math performance may be better for those with a natural knack for sensing number quantities. Previous studies looked at how sensing numbers affected performance, but researchers didn't know whether the natural ability to sense numbers or proficiency seeing numbers as symbols limited math skills. Pinpointing which factor affects learning in children will help teachers and researchers develop better programs for kids who may enter formal education at a disadvantage. For example, flashing a number of dots -- some blue, others red -- and asking someone to determine which group of objects there was more of is a common way to measure people's ability to sense numbers. The dots appear and disappear so quickly that it becomes impossible to count, so the amounts have to be sensed instead. Also called the Approximate Number System (ANS), this innate ability has been studied in adults, children, infants and even non-human animals. So far, researchers suggest that the accuracy of a person's ANS improves throughout childhood. The concept also falls within a larger area teachers and researchers refer to as "number sense," or the ability to count, discern quantities, pick up on number patterns and "to rule out unreasonable results to arithmetic operations," according to the paper. Specifically, people and animals subitize, or perceive and estimate the number of objects by glance. © 2011 Discovery Communications, LLC