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by Bob Holmes Lions might be one of the biggest threats to hyenas, but that doesn't stop the smaller animals teaming up to steal from the big cats. Nora Lewin from Michigan State University in East Lansing and her colleagues observed the mobbing behaviour at the Masai Mara National Reserve in Kenya. Hyenas were also spotted banding together to keep lions away from their dens. The mobbing involves a surprising degree of cooperation and communication. Male lions, which actively pursue and kill hyenas, are much more of a danger than females, who usually just make threats. This could be why the hyenas in the video above are confronting females. The team suggests the hyenas can identify their opponent's age and sex before deciding as a group whether or not to mob it. Levin and her colleagues are now investigating how the hyenas communicate to make a group decision. The findings were reported on 13 June at the annual meeting of the Animal Behavior Society in Anchorage, Alaska. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: 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: 21074 - Posted: 06.20.2015

Mo Costandi According to the old saying, the eyes are windows into the soul, revealing deep emotions that we might otherwise want to hide. Although modern science precludes the existence of the soul, it does suggest that there is a kernel of truth in this saying: it turns out the eyes not only reflect what is happening in the brain but may also influence how we remember things and make decisions. Our eyes are constantly moving, and while some of those movements are under conscious control, many of them occur subconsciously. When we read, for instance, we make a series of very quick eye movements called saccades that fixate rapidly on one word after another. When we enter a room, we make larger sweeping saccades as we gaze around. Then there are the small, involuntary eye movements we make as we walk, to compensate for the movement of our head and stabilise our view of the world. And, of course, our eyes dart around during the ‘rapid eye movement’ (REM) phase of sleep. What is now becoming clear is that some of our eye movements may actually reveal our thought process. Research published last year shows that pupil dilation is linked to the degree of uncertainty during decision-making: if somebody is less sure about their decision, they feel heightened arousal, which causes the pupils to dilate. This change in the eye may also reveal what a decision-maker is about to say: one group of researchers, for example, found that watching for dilation made it possible to predict when a cautious person used to saying ‘no’ was about to make the tricky decision to say ‘yes’. © 2015 Guardian News and Media Limited

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 7: Vision: From Eye to Brain
Link ID: 21011 - Posted: 06.02.2015

Monya Baker An ambitious effort to replicate 100 research findings in psychology ended last week — and the data look worrying. Results posted online on 24 April, which have not yet been peer-reviewed, suggest that key findings from only 39 of the published studies could be reproduced. But the situation is more nuanced than the top-line numbers suggest (See graphic, 'Reliability test'). Of the 61 non-replicated studies, scientists classed 24 as producing findings at least “moderately similar” to those of the original experiments, even though they did not meet pre-established criteria, such as statistical significance, that would count as a successful replication. The results should convince everyone that psychology has a replicability problem, says Hal Pashler, a cognitive psychologist at the University of California, San Diego, and an author of one of the papers whose findings were successfully repeated. “A lot of working scientists assume that if it’s published, it’s right,” he says. “This makes it hard to dismiss that there are still a lot of false positives in the literature.” But Daniele Fanelli, who studies bias and scientific misconduct at Stanford University in California, says the results suggest that the reproducibility of findings in psychology does not necessarily lag behind that in other sciences. There is plenty of room for improvement, he adds, but earlier studies have suggested that reproducibility rates in cancer biology and drug discovery could be even lower1, 2. “From my expectations, these are not bad at all,” Fanelli says. “Though I have spoken to psychologists who are quite disappointed.” © 2015 Nature Publishing Group,

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20871 - Posted: 05.02.2015

By JEFFREY ELY, ALEXANDER FRANKEL and EMIR KAMENICA IMAGINE the following situation. After a grueling day at work, you plop down in front of your TV, ready to relax. Your TiVo has recorded all of the day’s March Madness games. You’ve sequestered yourself away from any news about who won or lost. Which game to watch? Suddenly, your spouse pops in and tells you to stay away from Villanova versus Lafayette, which was a blowout, and to watch Baylor versus Georgia State, a nail-biter. Is this recommendation appreciated? Hardly. Baylor versus Georgia State was exciting because the unexpected happened: It was a back-and-forth affair in which Georgia State, the underdog, clinched the upset only in the final moments. But if you know in advance that it’s a nail-biter, you will expect the unexpected, ruining the surprise. It’s a lesson that the filmmaker M. Night Shyamalan, for one, seems to have missed. Once it’s common knowledge that your movie will have a dramatic, unexpected plot twist at the end, then your movie no longer has a dramatic, unexpected plot twist at the end. To be thrilling, you must occasionally be boring. This is one of several lessons that came out of our recent study of drama-based entertainment using the tools of information economics — the results of which were published in the Journal of Political Economy in February. When we recognize that the capacity to surprise an audience is a scarce resource (“You can’t fool all of the people all of the time”), it becomes natural to use economic theory to optimize that resource.

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20860 - Posted: 04.29.2015

Amy Coats Those split second decisions, made almost without thinking. When to put your foot on the pedal when you’re at the red light. When to check how those sausages are doing. Remembering to grab your lunch from the fridge seconds before you leave the house. Or – too often – 20 minutes after. And those carefully considered ones. Do I just finish this paragraph before I make a cup of tea? Or do I wait until the boss is clear of the kitchen? Timing, that is our perception and estimation of time, is key in determining how we behave and in the decisions we make. New findings suggest that time in the brain is relative, not absolute. This means that your brain ‘encodes’ your sense of time depending on what happens to you, and not by the second, minute or hour. And this in turn determines how you behave. Alas, you could be forgiven for feeling that the units of time common to everyone worldwide, except perhaps the odd Amazonian tribe, are pretty well ingrained. My partner and I will often make a quick bet on what time it is before we check our phone (all sigh!/rejoice! [delete as appropriate], the dwindling watch-less generation). And we’re both pretty good at getting to within 5 or 10 minutes, even if we haven’t known the exact time all day. He’s normally better at it, perhaps because he’s male? Perhaps it tends to fly/drag for me because I’m having more/less fun? Perhaps that’s another story. In the 2004 reality TV show Shattered, contestants who had been sleep-deprived for over 140 hours went head-to-head to predict when an arbitrary amount of time had passed – in this case, one minute and seven seconds. With the pressure of £100,000 prize money at stake, Dermot O’Leary grimacing nearby, a studio audience rustling in the darkness, and no cues except their ‘inner clock’, contestants were almost unbelievably close. The loser, Jonathan, was 0.4 seconds out, while Jimmy, the winner, was just one tenth of a second out. © 2015 Guardian News and Media Limited

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20859 - Posted: 04.29.2015

By Lawrence Berger A cognitive scientist and a German philosopher walk into the woods and come upon a tree in bloom: What does each one see? And why does it matter? While that may sound like the set-up to a joke making the rounds at a philosophy conference, I pose it here sincerely, as a way to explore the implications of two distinct strains of thought — that of cognitive science and that of phenomenology, in particular, the thought of Martin Heidegger, who offers a most compelling vision of the ultimate significance of our being here, and what it means to be fully human. When we feel that someone is really listening to us, we feel more alive, we feel our true selves coming to the surface — this is the sense in which worldly presence matters. It can be argued that cognitive scientists tend to ignore the importance of what many consider to be essential features of human existence, preferring to see us as information processors rather than full-blooded human beings immersed in worlds of significance. In general, their intent is to explain human activity and life as we experience it on the basis of physical and physiological processes, the implicit assumption being that this is the domain of what is ultimately real. Since virtually everything that matters to us as human beings can be traced back to life as it is experienced, such thinking is bound to be unsettling. For instance, an article in The Times last year by Michael S. A. Graziano, a professor of psychology and neuroscience at Princeton, about whether we humans are “really conscious,” argued, among other things, that “we don’t actually have inner feelings in the way most of us think we do.” © 2015 The New York Times Company

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20738 - Posted: 03.31.2015

Brian Owens Our choice between two moral options might be swayed by tracking our gaze, and asking for a decision at the right moment. People asked to choose between two written moral statements tend to glance more often towards the option they favour, experimental psychologists say. More surprisingly, the scientists also claim it’s possible to influence a moral choice: asking for an immediate decision as soon as someone happens to gaze at one statement primes them to choose that option. It’s well known that people tend to look more towards the option they are going to choose when they are choosing food from a menu, says Philip Pärnamets, a cognitive scientist from Lund University in Sweden. He wanted to see if that applied to moral reasoning as well. “Moral decisions have long been considered separately from general decision-making,” he says. “I wanted to integrate them.” In a paper published today in the Proceedings of the National Academy of Sciences1, Pärnamets and his colleagues explain how they presented volunteers with a series of moral statements, such as 'murder is sometimes justified,' 'masturbating with the aid of a willing animal is acceptable' and 'paying taxes is a good thing.' Then the psychologists tracked the volunteers’ gaze as two options appeared on a screen. Once the tracker had determined that a person had spent at least 750 milliseconds looking at one answer and 250 milliseconds at the other, the screen changed to prompt them to make a decision. Almost 60% of the time, they chose the most viewed option — indicating, says Pärnamets, that eye gaze tracks an unfolding moral decision. © 2015 Nature Publishing Group,

Related chapters from BP7e: 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: 20694 - Posted: 03.17.2015

|By Esther Landhuis As we age, we seem to get worse at ignoring irrelevant stimuli. It's what makes restaurant conversations challenging—having to converse while also shutting out surrounding chatter. New research bears out the aging brain's distractibility but also suggests that training may help us tune out interference. Scientists at Brown University recruited seniors and twentysomethings for a visual experiment. Presented with a sequence of letters and numbers, participants were asked to report back only the numbers—all the while disregarding a series of meaningless dots. Sometimes the dots moved randomly, but other times they traveled in a clear direction, making them harder to ignore. Older participants ended up accidentally learning the dots' patterns, based on the accuracy of their answers when asked which way the dots were moving, whereas young adults seemed able to suppress that information and focus on the numbers, the researchers reported last November in Current Biology. In a separate study published in Neuron, scientists at the University of California, San Francisco, showed they could train aging brains to become less distractible. Their regimen helped aging rats as well as older people. The researchers played three different sounds and rewarded trainees for identifying a target tone while ignoring distracter frequencies. As the subjects improved, the task grew more challenging—the distracting tone became harder to discriminate from the target. © 2015 Scientific American,

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 13: Memory, Learning, and Development
Link ID: 20681 - Posted: 03.12.2015

Robin Tricoles The first time it happened, I was 8. I was tucked in bed reading my favorite book when my tongue swelled up to the size of a cow’s, like the giant tongues I had seen in the glass display case at the neighborhood deli. At the same time, the far wall of my bedroom began to recede, becoming a tiny white rectangle floating somewhere in the distance. In the book I was holding, the typeface grew vast on the page. I was intrigued, I remember, but not afraid. Over the next six years, the same thing happened to me dozens of times. Forty years later, while working as a science writer, I stumbled on a scientific paper describing almost exactly what I had experienced. The paper attributed those otherworldly sensations to something called Alice in Wonderland syndrome, or its close cousin, Alice in Wonderland-like syndrome. People with Alice in Wonderland syndrome (AWS) perceive parts of their body to be changing size. For example, their feet may suddenly appear smaller and more distant, or their hands larger than they had been moments before. Those with the closely related Alice in Wonderland-like syndrome (AWLS) misperceive the size and distance of objects, seeing them as startlingly larger, smaller, fatter, or thinner than their natural state. People who experience both sensations, like I did, are classified as having AWLS. The syndrome’s name is commonly attributed to English psychiatrist John Todd, who in 1955 described his adult patients’ illusions of corporal and objective distortions in a paper in the Canadian Medical Association Journal. © 2015 by The Atlantic Monthly Group.

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20672 - Posted: 03.10.2015

by Helen Thomson We meet in a pub, we have a few drinks, some dinner and then you lean in for a kiss. You predict, based on our previous interactions, that the kiss will be reciprocated – rather than landing you with a slap in the face. All our social interactions require us to anticipate another person's undecided intentions and actions. Now, researchers have discovered specific brain cells that allow monkeys to do this. It is likely that the cells do the same job in humans. Keren Haroush and Ziv Williams at Harvard Medical School trained monkeys to play a version of the prisoner's dilemma, a game used to study cooperation. The monkeys sat next to each other and decided whether or not they wanted to cooperate with their companion, by moving a joystick to pick either option. Moving the joystick towards an orange circle meant cooperate, a blue triangle meant "not this time". Neither monkey could see the other's face, or receive any clues about their planned action. If the monkeys cooperated, both received four drops of juice. If one cooperated and the other decided not to, the one who cooperated received one drop, and the other received six drops of juice. If both declined to work together they both received two drops of juice. Once both had made their selections, they could see what the other monkey had chosen and hear the amount of juice their companion was enjoying. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20627 - Posted: 02.27.2015

By Christie Aschwanden Paul Offit likes to tell a story about how his wife, pediatrician Bonnie Offit, was about to give a child a vaccination when the kid was struck by a seizure. Had she given the injection a minute sooner, Paul Offit says, it would surely have appeared as though the vaccine had caused the seizure and probably no study in the world would have convinced the parent otherwise. (The Offits have such studies at the ready — Paul is the director of the Vaccine Education Center at the Children’s Hospital of Philadelphia and author of “Deadly Choices: How the Anti-Vaccine Movement Threatens Us All.”) Indeed, famous anti-vaxxer Jenny McCarthy has said her son’s autism and seizures are linked to “so many shots” because vaccinations preceded his symptoms. But, as Offit’s story suggests, the fact that a child became sick after a vaccine is not strong evidence that the immunization was to blame. Psychologists have a name for the cognitive bias that makes us prone to assigning a causal relationship to two events simply because they happened one after the other: the “illusion of causality.” A study recently published in the British Journal of Psychology investigates how this illusion influences the way we process new information. Its finding: Causal illusions don’t just cement erroneous ideas in the mind; they can also prevent new information from correcting them. Helena Matute, a psychologist at Deusto University in Bilbao, Spain, and her colleagues enlisted 147 college students to take part in a computer-based task in which they each played a doctor who specializes in a fictitious rare disease and assessed whether new medications could cure it. ©2015 ESPN Internet Ventures.

Related chapters from BP7e: 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: 20595 - Posted: 02.19.2015

Tom Stafford Trusting your instincts may help you to make better decisions than thinking hard, a study suggests. It is a common misconception that we know our own minds. As I move around the world, walking and talking, I experience myself thinking thoughts. "What shall I have for lunch?", I ask myself. Or I think, "I wonder why she did that?" and try and figure it out. It is natural to assume that this experience of myself is a complete report of my mind. It is natural, but wrong. There's an under-mind, all psychologists agree – an unconscious which does a lot of the heavy lifting in the process of thinking. If I ask myself what is the capital of France the answer just comes to mind – Paris! If I decide to wiggle my fingers, they move back and forth in a complex pattern that I didn't consciously prepare, but which was delivered for my use by the unconscious. The big debate in psychology is exactly what is done by the unconscious, and what requires conscious thought. Or to use the title of a notable paper on the topic, 'Is the unconscious smart or dumb?' One popular view is that the unconscious can prepare simple stimulus-response actions, deliver basic facts, recognise objects and carry out practised movements. Complex cognition involving planning, logical reasoning and combining ideas, on the other hand, requires conscious thought. A recent experiment by a team from Israel scores points against this position. Ran Hassin and colleagues used a neat visual trick called Continuous Flash Suppression to put information into participants’ minds without them becoming consciously aware of it.

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20594 - Posted: 02.19.2015

By Virginia Morell To prevent their hives from being attacked by invaders, wasps must quickly distinguish friend from foe. They typically do this by sniffing out foreigners, as outsiders tend to have a different scent than the home colony. Now researchers have discovered that, like a few other wasp species, a tiny social wasp (Liostenogaster flavolineata) from Malaysia employs an additional security measure: facial recognition. The wasps’ nests are typically found in large aggregations with as many as 150 built close together, and each colony faces persistent landing attempts by outsiders from these other nests. To find out why and how these wasps employ both vision and scent to determine if an incoming wasp is a comrade, scientists carried out a series of experiments on 50 colonies (see photo above) in the wild. Close to the nests, the researchers dangled lures made of captured and killed wasps. The lures had been given different treatments. For instance, some lures made from nest mates were coated with a foe’s scent, whereas outsiders were painted with the colony’s odor. The wasps, it turns out, pay more attention to facial markings than to scent when faced with a possible intruder, the team reports online today in the Proceedings of the Royal Society B. Indeed, in tests where the wasps could assess both an intruder’s face and scent, they relied solely on facial recognition and immediately attacked those whose faces they didn’t know, ignoring their odor. That’s the safest strategy, the scientists note, because the wasps can recognize another’s face at a distance, but need to actually touch another wasp to detect her scent—not a bad ploy for a tiny-brained insect. © 2015 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 15: Language and Our Divided Brain
Link ID: 20547 - Posted: 02.05.2015

By ERICA GOODE A study suggests that newborn chicks map numbers spatially, associating low numerical values with space to their left. Credit Rosa Rugani/University of Padova Asked to picture the numbers from one to 10, most people will imagine a straight line with one at the left end and 10 at the right. This “mental number line,” as researchers have termed it, is so pervasive that some scientists have argued that the spatial representation of numbers is hard-wired into the brain, part of a primitive number system that underlies humans’ capacity for higher mathematics. Now a team of Italian researchers has found that newborn chicks, like humans, appear to map numbers spatially, associating smaller amounts with the left side and larger amounts with the right side. The chicks, trained to seek out mealworms behind white plastic panels printed with varying numbers of identical red squares, repeatedly demonstrated a preference for the left when the number of squares was small and for the right when the number was larger. The research, led by Rosa Rugani, a psychologist who at the time was at the University of Padova, will appear in Friday’s issue of the journal Science. Researchers demonstrated that chickens naturally order numbers left to right. When the number five is in the middle, chickens naturally go left for lower numbers and to the right for higher numbers. Publish Date January 29, 2015. In their report, the researchers said the findings supported the idea that the left-right orientation for numbers is innate rather than determined by culture or education — a possibility that was raised by some studies that found that in Arabic-speaking countries where letters and numbers are read right to left, the mental number scale was reversed. But the new research, Dr. Rugani and her colleagues wrote, indicates that orienting numbers in space may represent “a universal cognitive strategy available soon after birth.” Tyler Marghetis, a doctoral candidate in psychology at the University of California, San Diego, who has published research on the spatial association of numbers, called the researcher’s studies “very cool.” © 2015 The New York Times Company

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition; Chapter 19: Language and Hemispheric Asymmetry
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 15: Language and Our Divided Brain
Link ID: 20538 - Posted: 01.31.2015

Alison Abbott If you have to make a complex decision, will you do a better job if you absorb yourself in, say, a crossword puzzle instead of ruminating about your options? The idea that unconscious thought is sometimes more powerful than conscious thought is attractive, and echoes ideas popularized by books such as writer Malcolm Gladwell’s best-selling Blink. But within the scientific community, ‘unconscious-thought advantage’ (UTA) has been controversial. Now Dutch psychologists have carried out the most rigorous study yet of UTA — and find no evidence for it. Their conclusion, published this week in Judgement and Decision Making, is based on a large experiment that they designed to provide the best chance of capturing the effect should it exist, along with a sophisticated statistical analysis of previously published data1. The report adds to broader concerns about the quality of psychology studies and to an ongoing controversy about the extent to which unconscious thought in general can influence behaviour. “The bigger debate is about how clever our unconscious is,” says cognitive psychol­ogist David Shanks of University College London. “This carefully constructed paper makes a great contribution.” Shanks published a review last year that questioned research claiming that various unconscious influences, including UTA, affect decision making2. © 2015 Nature Publishing Group

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 13: Memory, Learning, and Development
Link ID: 20528 - Posted: 01.28.2015

|By Christof Koch Faces are the glue that holds us together and that gives us our identity. All of us but the visually impaired and blind are experts at recognizing people's identity, gender, age and ethnicity from looking at their faces. First impressions of attractiveness or competence take but a brief glimpse of somebody's face. Newly born infants already tend to fixate on faces. This bias also turns up in art. Paintings and movies are filled with faces staring at the viewer. Who can forget the endless close-ups of the feuding husband and wife in Ingmar Bergman's Cimmerian masterpiece Scenes from a Marriage? Because recognizing a face is so vital to our social lives, it comes as no surprise that a lot of real estate in the cerebral cortex—the highly convoluted region that makes up the bulk of our brain—is devoted to a task crucial to processing faces and their identity. We note whether someone looks our way or not. We discern emotional expressions, whether they register joy, fear or anger. Indeed, functional brain imaging has identified a set of adjacent regions, referred to as the fusiform face area (FFA), that are situated on the left and the right sides of the brain, at the bottom of the temporal lobe of the cerebral cortex. The FFA turns up its activity when subjects look at portraits or close-ups of faces or even when they just think about these images. Two just published studies of the brain's visual networks, including the FFA, enlarge what we know about the physical basis of face perception. Both explore the unique access to the brain afforded by patients whose epileptic seizures have proved resistant to drugs. A surgical treatment finds the locations in the brain where the hypersynchronized activity that characterizes a seizure begins before spreading from its point of origin to engulf one or sometimes both hemispheres. If a single point—a focus where the seizure begins—can be found, it can be removed. After this procedure, a patient usually has significantly fewer seizures—and some remain seizure-free. To triangulate the location of the focus, neurosurgeons insert electrodes into the brain to monitor electrical activity that occurs during a seizure. © 2015 Scientific American

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20523 - Posted: 01.27.2015

|By Stephen L. Macknik and Susana Martinez-Conde To a neuroscientist, the trouble with cocktail parties is not that we do not love cocktails or parties (many neuroscientists do). Instead what we call “the cocktail party problem” is the mystery of how anyone can have a conversation at a cocktail party at all. Consider a typical scene: You have a dozen or more lubricated and temporarily uninhibited adults telling loud, improbable stories at increasing volumes. Interlocutors guffaw and slap backs. Given the decibel level, it is a minor neural miracle that any one of these revelers can hear and parse one word from any other. The alcohol does not help, but it is not the main source of difficulties. The cocktail party problem is that there is just too much going on at once: How can our brain filter out the noise to focus on the wanted information? This problem is a central one for perceptual neuroscience—and not just during cocktail parties. The entire world we live in is quite literally too much to take in. Yet the brain does gather all of this information somehow and sorts it in real time, usually seamlessly and correctly. Whereas the physical reality consists of comparable amounts of signal and noise for many of the sounds and sights around you, your perception is that the conversation or object that interests you remains in clear focus. So how does the brain accomplish this feat? One critical component is that our neural circuits simplify the problem by actively ignoring—suppressing—anything that is not task-relevant. Our brain picks its battles. It stomps out irrelevant information so that the good stuff has a better chance of rising to awareness. This process, colloquially called attention, is how the brain sorts the wheat from the chaff. © 2014 Scientific American

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 7: Vision: From Eye to Brain
Link ID: 20440 - Posted: 12.23.2014

Kate Szell “I once asked Clara who she was. It was so embarrassing, but she’d had a haircut, so how was I to know?” That’s Rachel, she’s 14 and counts Clara as one of her oldest and best friends. There’s nothing wrong with Rachel’s sight, yet she struggles to recognise others. Why? Rachel is face blind. Most of us take for granted the fact that we recognise someone after a quick glance at their face. We don’t realise we’re doing something very different when we look at a face compared with when we look at anything else. To get a feeling of how peculiar facial recognition is, try recognising people by looking at their hands, instead of their faces. Tricky? That’s exactly how Rachel feels – only she’s not looking at hands, she’s looking straight into someone’s eyes. Specific areas of the brain process facial information. Damage to those areas gives rise to prosopagnosia or “face blindness”: an inability or difficulty with recognising faces. While brain damage-induced prosopagnosia is rare, prosopagnosia itself is not. Studies suggest around 2% of the population could have some form of prosopagnosia. These “developmental” prosopagnosics seem to be born without the ability to recognise faces and don’t acquire it, relying instead on all manner of cues, from gait to hairstyles, to tell people apart. Kirsten Dalrymple from the University of Minnesota is one of a handful of researchers looking into developmental prosopagnosia. Her particular interest is in prosopagnosic children. “Some seem to cope without much of a problem but, for others, it’s a totally different story,” she says. “They can become very socially withdrawn and can also be at risk of walking off with strangers.” © 2014 Guardian News and Media Limited o

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20347 - Posted: 11.24.2014

By Meeri Kim Patients suffering from pagophagia compulsively crave and chomp on ice, even scraping buildup off freezer walls for a fix. The disorder appears to be caused by an iron deficiency, and supplements of the mineral tend to ease the cravings. But what is it about ice that makes it so irresistible? A new study proposes that, like a strong cup of coffee, ice may give those with insufficient iron a much-needed mental boost. Fatigue is the most common symptom of iron-deficiency anemia, which occurs when the body can’t produce enough oxygen-carrying hemoglobin because of low iron. “I had a friend who was suffering from iron-deficiency anemia who was just crunching through massive amounts of ice a day,” said study author Melissa Hunt, a clinical psychologist at the University of Pennsylvania. “She said: ‘It’s like a cup of coffee. I don’t feel awake until I have a cup of ice in my hand.’ ” Hunt and her colleagues had both anemic and healthy subjects complete a standardized, 22-minute attention test commonly used to diagnose attention deficit hyperactivity disorder. Just before the test, participants were given either a cup of ice or lukewarm water to consume. Iron-deficient subjects who had sipped on water performed far more slugglishly on the test than controls, as expected. But those who ate ice beforehand did just as well as their healthy counterparts. For healthy subjects, having a cup of ice instead of water appeared to make no difference in test performance. “It’s not like craving a dessert. It’s more like needing a cup of coffee or that cigarette,” Hunt said.

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Consciousness
Link ID: 20296 - Posted: 11.10.2014

By Greg Miller This robot causes people to experience the illusory sensation of someone standing behind them. © Alain Herzog/EPFL People who’ve stared death in the face and lived to tell about it—mountain climbers who’ve made a harrowing descent, say, or survivors of the World Trade Center attacks—sometimes report that just when their situation seemed impossible, a ghostly presence appeared. People with schizophrenia and certain types of neurological damage sometimes report similar experiences, which scientists call, aptly, “feeling of presence.” Now a team of neuroscientists says it has identified a set of brain regions that seems to be involved in generating this illusion. Better yet, they’ve built a robot that can cause ordinary people to experience it in the lab. The team was led by Olaf Blanke, a neurologist and neuroscientist at the Swiss Federal Institute of Technology in Lausanne. Blanke has a long-standing interest in creepy illusions of bodily perception. Studying these bizarre phenomena, he says, could point to clues about the biology of mental illness and the mechanisms of human consciousness. In 2006, for example, Blanke and colleagues published a paper in Nature that had one of the best titles you’ll ever see in a scientific journal: “Induction of an illusory shadow person.” In that study, they stimulated the brain of a young woman who was awaiting brain surgery for severe epilepsy. Surgeons had implanted electrodes on the surface of her brain to monitor her seizures, and when the researchers passed a mild current through the electrodes, stimulating a small region at the intersection of the temporal and parietal lobes of her brain, she experienced what she described as a shadowy presence lurking nearby, mimicking her own posture. Colored areas indicate regions of overlap in the lesions of neurological patients who experienced feeling of presence illusions. © 2014 Condé Nast.

Related chapters from BP7e: 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: 20290 - Posted: 11.08.2014