Chapter 14. Attention and Consciousness
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Hannah Devlin The human brain is predisposed to learn negative stereotypes, according to research that offers clues as to how prejudice emerges and spreads through society. The study found that the brain responds more strongly to information about groups who are portrayed unfavourably, adding weight to the view that the negative depiction of ethnic or religious minorities in the media can fuel racial bias. Hugo Spiers, a neuroscientist at University College London, who led the research, said: “The newspapers are filled with ghastly things people do ... You’re getting all these news stories and the negative ones stand out. When you look at Islam, for example, there’s so many more negative stories than positive ones and that will build up over time.” The scientists also uncovered a characteristic brain signature seen when participants were told a member of a “bad” group had done something positive - an observation that is likely to tally with the subjective experience of minorities. “Whenever someone from a really bad group did something nice they were like, ‘Oh, weird,’” said Spiers. Previous studies have identified brain areas involved in gender or racial stereotyping, but this is the first attempt to investigate how the brain learns to link undesirable traits to specific groups and how this is converted into prejudice over time. © 2016 Guardian News and Media Limited
Link ID: 22821 - Posted: 11.02.2016
Laura Sanders The eyes may reveal whether the brain’s internal stopwatch runs fast or slow. Pupil size predicted whether a monkey would over- or underestimate a second, scientists report in the Nov. 2 Journal of Neuroscience. Scientists knew that pupils get bigger when a person is paying attention. They also knew that paying attention can influence how people perceive the passage of time. Using monkeys, the new study links pupil size and timing directly. “What they’ve done here is connect those dots,” says neuroscientist Thalia Wheatley of Dartmouth College. More generally, the study shows how the eyes are windows into how the brain operates. “There’s so much information coming out of the eyes,” Wheatley says. Neuroscientist Masaki Tanaka of Hokkaido University School of Medicine in Japan and colleagues trained three Japanese macaques to look at a spot on a computer screen after precisely one second had elapsed. The study measured the monkeys’ subjective timing abilities: The monkeys had to rely on themselves to count the milliseconds. Just before each trial, the researchers measured pupil diameters. When the monkeys underestimated a second by looking too soon, their pupil sizes were slightly larger than in trials in which the monkeys overestimated a second, the researchers found. That means that when pupils were large, the monkeys felt time zoom by. But when pupils were small, time felt slower. |© Society for Science & the Public 2000 - 2016.
Link ID: 22818 - Posted: 11.02.2016
Nicola Davis The proficiency of elite football referees could be down to their eagle eyes, say researchers. A study of elite and sub-elite referees has found that a greater tendency to predict and watch contact zones between players contributes to the greater accuracy of top-level referees. “Over the years they develop so much experience that they now can anticipate, very well, future events so that they can already direct their attention to those pieces of information where they expect something to happen,” said lead author Werner Helsen from the University of Leuven. Keith Hackett, a former football referee and former general manager of the Professional Game Match Officials Limited, said the research chimed with his own experiences. “In working with elite referees for a number of years I have recognised their ability to see, recognise think and then act in a seamless manner,” he said. “They develop skill sets that enable them to see and this means good game-reading and cognitive skills to be in the right place at the right time.” Mistakes, he believes, often come down to poor visual perception. “Last week, we saw an elite referee fail to detect the violent act of [Moussa] Sissoko using his arm/elbow, putting his opponent’s safety at risk,” he said. “The review panel, having received confirmation from the referee that he failed to see the incident despite looking in the direction of the foul challenge, were able to act.” Writing in the journal Cognitive Research, researchers from the University of Leuven in Belgium and Brunel University in west London say they recruited 39 referees, 20 of whom were elite referees and 19 were experienced but had never refereed at a professional level. © 2016 Guardian News and Media Limited
Link ID: 22817 - Posted: 11.01.2016
By Jesse Singal For a long time, the United States’ justice system has been notorious for its proclivity for imprisoning children. Because of laws that grant prosecutors and judges discretion to bump juveniles up to the category of “adult” when they commit crimes deemed serious enough by the authorities, the U.S. is an outlier in locking up kids, with some youthful defendants even getting life sentences. Naturally, this has attracted a great deal of outrage and advocacy from human-rights organizations, who argue that kids, by virtue of not lacking certain judgment, foresight, and decision-making abilities, should be treated a bit more leniently. Writing for the Marshall Project and drawing on some interesting brain science, Dana Goldstein takes the argument about youth incarceration even further: We should also rethink our treatment of offenders who are young adults. As Goldstein explains, the more researchers study the brain, the more they realize that it takes decades for the organ to develop fully and to impart to its owners their full, adult capacities for reasoning. “Altogether,” she writes, “the research suggests that brain maturation continues into one’s twenties and even thirties.” Many of these insights come from the newest generation of neuroscience research. “Everyone has always known that there are behavioral changes throughout the lifespan,” Catherine Lebel, an assistant professor of radiology at the University of Calgary who has conducted research into brain development, told Goldstein. “It’s only with new imaging techniques over the last 15 years that we’ve been able to get at some of these more subtle changes.” ! © 2016, New York Media LLC.
By Diana Kwon Can you feel your heart beating? Most people cannot, unless they are agitated or afraid. The brain masks the sensation of the heart in a delicate balancing act—we need to be able to feel our pulse racing occasionally as an important signal of fear or excitement, but most of the time the constant rhythm would be distracting or maddening. A growing body of research suggests that because of the way the brain compensates for our heartbeat, it may be vulnerable to perceptual illusions—if they are timed just right. In a study published in May in the Journal of Neuroscience, a team at the Swiss Federal Institute of Technology in Lausanne conducted a series of studies on 143 participants and found that subjects took longer to identify a flashing object when it appeared in sync with the rhythm of their heartbeats. Using functional MRI, they also found that activity in the insula, a brain area associated with self-awareness, was suppressed when people viewed these synchronized images. The authors suggest that the flashing object was suppressed by the brain because it got lumped in with all the other bodily changes that occur with each heartbeat—the eyes make tiny movements, eye pressure changes slightly, the chest expands and contracts. “The brain knows that the heartbeat is coming from the self, so it doesn't want to be bothered by the sensory consequences of these signals,” says Roy Salomon, one of the study's co-authors. © 2016 Scientific American
By Melissa Dahl A rule that spans time and space and morning routines: It is entirely too easy to underestimate the time it takes to get to work. Maybe once — one time — it took just 20 minutes to get to work, but it typically takes 25 to 30, and you know that, but still you leave late and, thus, arrive late. It’s dumb. It is also, maybe, human nature. As Christian Jarrett at BPS Research Digest reports, a team of neuroscientists has just uncovered a very handy if rather complicated excuse for tardiness — it seems people tend to underestimate how long it will take to travel familiar routes. The laws of time and space do not actually bend in order to transport you to work or school more quickly, but at least part of you believes that they will. And yet the oddest part of this new study, published in the journal Hippocampus, is that the participants tended to overestimate the physical length of those routes, even as they underestimated how long it would take to travel them. It does make a certain amount of sense that people would exaggerate the breadth of familiar distances, because the level of detail you’ve stored about them matters to your memory. If you remember every Starbucks and street corner you pass on the way you usually walk to school, for instance, the walking route will likely feel longer when you recall it than one you don’t know as well. As Jarrett explains, the researchers “thought a more detailed neural representation would make that space seem larger.” And when they asked a group of students — all of whom had been living in the same building in London for 9 months — to draw a little map of their neighborhood, this is indeed what they found. The students exaggerated the physical distance of the routes they walked the most, drawing their maps a little bigger they should have. © 2016, New York Media LLC.
Link ID: 22797 - Posted: 10.28.2016
By Michael-Paul Schallmo, Scott Murray, Most people do not associate autism with visual problems. It’s not obvious how atypical vision might be related to core features of autism such as social and language difficulties and repetitive behaviors. Yet examining how autism affects vision holds tremendous promise for understanding this condition at a neural level. Over the past 50 years, we have learned more about the visual parts of the brain than any other areas, and we have a solid understanding of how neural activity leads to visual perception in a typical brain. Differences in neuronal processing in autism are likely to be widespread, and may be similar across brain regions. So pinpointing these differences in visual areas might reveal important details about processing in brain regions related to social functioning and language, which are not as well understood. Studying vision in autism may also help connect studies of people to those of animal models. Working with animals allows neuroscientists to study neural processing at many different levels—from specific genes and single neurons to small neural networks and brain regions that control functions such as movement or hearing. But animals do not display the complexity and diversity in language and social functioning that people do. By contrast, visual brain processes are similar between people and animals. We can use our rich knowledge of how neurons in animals process visual information to bridge the gap between animals and people. We can also use it to test hypotheses about how autism alters neural functioning in the brain. © 2016 Scientific American
By KATE MURPHY Eavesdrop on any conversation or pay close attention to your own and you’ll hear laughter. From explosive bursts to muffled snorts, some form of laughter punctuates almost all verbal communication. Electronic communication, too, LOL. You’ll probably also notice that, more often than not, the laughter is in response to something that wasn’t very funny — or wasn’t funny at all. Observational studies suggest this is the case 80 percent to 90 percent of the time. Take Hillary Clinton’s strategic laughter during heated exchanges with Donald J. Trump during the presidential debates. Or Jimmy Fallon’s exaggerated laughter when interviewing guests on “The Tonight Show.” Or employees at Fox News reporting that they tried to “laugh off” unwanted sexual advances by Roger Ailes and others within the organization. How laughter went from a primal signal of safety (the opposite of a menacing growl) to an odd assortment of vocalizations that smooth as much as confuse social interactions is poorly understood. But researchers who study laughter say reflecting on when and why you titter, snicker or guffaw is a worthy exercise, given that laughter can harm as much as help you. “It’s a hall of mirrors of inferences and intentions every time you encounter laughter,” said Sophie Scott, a neuroscientist at University College London who studies how the brain produces and processes laughter. “You think it’s so simple. It’s just jokes and ha-ha but laughter is really sophisticated and complicated.” Laughter at its purest and most spontaneous is affiliative and bonding. To our forebears it meant, “We’re not going to kill each other! What a relief!” But as we’ve developed as humans so has our repertoire of laughter, unleashed to achieve ends quite apart from its original function of telling friend from foe. Some of it is social lubrication — the warm chuckles we give one another to be amiable and polite. Darker manifestations include dismissive laughter, which makes light of something someone said sincerely, and derisive laughter, which shames. © 2016 The New York Times Company
By Kensy Cooperrider, Rafael Núñez “What is the difference between yesterday and tomorrow?” The Yupno man we were interviewing, Danda, paused to consider his answer. A group of us sat on a hillside in the Yupno Valley, a remote nook high in the mountains of Papua New Guinea. Only days earlier we had arrived on a single-engine plane. After a steep hike from the grass airstrip, we found ourselves in the village of Gua, one of about 20 Yupno villages dotting the rugged terrain. We came all the way here because we are interested in time—in how Yupno people understand concepts such as past, present and future. Are these ideas universal, or are they products of our language, our culture and our environment? As we interviewed Danda and others in the village, we listened to what they said about time, but we paid even closer attention to what they did with their hands as they spoke. Gestures can be revealing. Ask English speakers about the difference between yesterday and tomorrow, and they might thrust a hand over the shoulder when referring to the past and then forward when referring to the future. Such unreflective movements reveal a fundamental way of thinking in which the past is at our backs, something that we “leave behind,” and the future is in front of us, something to “look forward” to. Would a Yupno speaker do the same? Danda was making just the kinds of gestures we were hoping for. As he explained the Yupno word for “yesterday,” his hand swept backward; as he mentioned “tomorrow,” it leaped forward. We all sat looking up a steep slope toward a jagged ridge, but as the light faded, we changed the camera angle, spinning around so that we and Danda faced in the opposite direction, downhill. With our backs now to the ridge, we looked over the Yupno River meandering toward the Bismarck Sea. “Let's go over that one more time,” we suggested. © 2016 Scientific American,
Link ID: 22778 - Posted: 10.22.2016
By Catherine Caruso Imagine you are faced with the classic thought experiment dilemma: You can take a pile of money now or wait and get an even bigger stash of cash later on. Which option do you choose? Your level of self-control, researchers have found, may have to do with a region of the brain that lets us take the perspective of others—including that of our future self. A study, published today in Science Advances, found that when scientists used noninvasive brain stimulation to disrupt a brain region called the temporoparietal junction (TPJ), people appeared less able to see things from the point of view of their future selves or of another person, and consequently were less likely to share money with others and more inclined to opt for immediate cash instead of waiting for a larger bounty at a later date. The TPJ, which is located where the temporal and parietal lobes meet, plays an important role in social functioning, particularly in our ability to understand situations from the perspectives of other people. However, according to Alexander Soutschek, an economist at the University of Zurich and lead author on the study, previous research on self-control and delayed gratification has focused instead on the prefrontal brain regions involved in impulse control. “When you have a closer look at the literature, you sometimes find in the neuroimaging data that the TPJ is also active during delay of gratification,” Soutschek says, “but it's never interpreted.” © 2016 Scientific American
Link ID: 22772 - Posted: 10.20.2016
By DONNA DE LA CRUZ Some of the most troubling images of the opioid crisis involve parents buying or using drugs with their children in tow. Now new research offers a glimpse into the addicted brain, finding that the drugs appear to blunt a person’s natural parenting instincts. Researchers at the Perelman School of Medicine at the University of Pennsylvania scanned the brains of 47 men and women before and after they underwent treatment for opioid dependence. While in the scanner, the study subjects looked at various images of babies, and the researchers measured the brain’s response. The brain scans were compared with the responses of 25 healthy people. What the study subjects didn’t know was that the photos had been manipulated to adjust the “baby schema,” the term used to describe the set of facial and other features like round faces and big eyes that make our brains register babies as irresistible, kicking in our instinct to care for them. Sometimes the babies’ features were exaggerated to make them even more adorable; in others, the chubby cheeks and big eyes were reduced, making the faces less appealing. Studies show that a higher baby schema activates the part of the brain called the ventral striatum, a key component of the brain reward pathway. Compared with the brains of healthy people, the brains of people with opioid dependence didn’t produce strong responses to the cute baby pictures. But once the opioid-dependent people received a drug called naltrexone, which blocks the effects of opioids, their brains produced a more normal response. “When the participants were given an opioid blocker, their baby schema became more similar to that of healthy people,” said Dr. Daniel D. Langleben, one of the researchers. “The data also raised in question whether opioid medications may affect social cognition in general.” © 2016 The New York Times Company
By CASEY SCHWARTZ Have you ever been to Enfield? I had never even heard of it until I was 23 and living in London for graduate school. One afternoon, I received notification that a package whose arrival I had been anticipating for days had been bogged down in customs and was now in a FedEx warehouse in Enfield, an unremarkable London suburb. I was outside my flat within minutes of receiving this news and on the train to Enfield within the hour, staring through the window at the gray sky. The package in question, sent from Los Angeles, contained my monthly supply of Adderall. Adderall, the brand name for a mixture of amphetamine salts, is more strictly regulated in Britain than in the United States, where, the year before, in 2005, I became one of the millions of Americans to be prescribed a stimulant medication. The train to Enfield was hardly the greatest extreme to which I would go during the decade I was entangled with Adderall. I would open other people’s medicine cabinets, root through trash cans where I had previously disposed of pills, write friends’ college essays for barter. Once, while living in New Hampshire, I skipped a day of work to drive three hours each way to the health clinic where my prescription was still on file. Never was I more resourceful or unswerving than when I was devising ways to secure more Adderall. Adderall is prescribed to treat Attention Deficit Hyperactivity Disorder, a neurobehavioral condition marked by inattention, hyperactivity and impulsivity that was first included in the D.S.M. in 1987 and predominantly seen in children. That condition, which has also been called Attention Deficit Disorder, has been increasingly diagnosed over recent decades: In the 1990s, an estimated 3 to 5 percent of school-age American children were believed to have A.D.H.D., according to the Centers for Disease Control and Prevention; by 2013, that figure was 11 percent. It continues to rise. And the increase in diagnoses has been followed by an increase in prescriptions. In 1990, 600,000 children were on stimulants, usually Ritalin, an older medication that often had to be taken multiple times a day. By 2013, 3.5 million children were on stimulants, and in many cases, the Ritalin had been replaced by Adderall, officially brought to market in 1996 as the new, upgraded choice for A.D.H.D. — more effective, longer lasting. © 2016 The New York Times Company
Bruce Bower Apes understand what others believe to be true. What’s more, they realize that those beliefs can be wrong, researchers say. To make this discovery, researchers devised experiments involving a concealed, gorilla-suited person or a squirreled-away rock that had been moved from their original hiding places — something the apes knew, but a person looking for King Kong or the stone didn’t. “Apes anticipated that an individual would search for an object where he last saw it, even though the apes knew that the object was no longer there,” says evolutionary anthropologist Christopher Krupenye. If this first-of-its-kind finding holds up, it means that chimpanzees, bonobos and orangutans can understand that others’ actions sometimes reflect mistaken assumptions about reality. Apes’ grasp of others’ false beliefs roughly equals that of human 2-year-olds tested in much the same way, say Krupenye of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and his colleagues. Considering their targeted gazes during brief experiments, apes must rapidly assess others’ beliefs about the world in wild and captive communities, the researchers propose in the October 7 Science. Understanding the concept of false beliefs helps wild and captive chimps deceive their comrades, such as hiding food from those who don’t share, Krupenye suggests. |© Society for Science & the Public 2000 - 2016.
In his memoir Do No Harm, Henry Marsh confesses to the uncertainties he's dealt with as a surgeon and reflects on the enigmas of the brain and consciousness. Originally broadcast May 26, 2015. DAVE DAVIES, HOST: This is FRESH AIR. I'm Dave Davies, sitting in for Terry Gross. Our guest has opened heads and cut into brains, performing delicate and risky surgery on the part of the body that controls everything - breathing, movement, memory, and consciousness. In his work as a neurosurgeon, Dr. Henry Marsh has fixed aneurysms and spinal problems and spent many years operating on brain tumors. In his memoir, Dr. Marsh discusses some of his most challenging cases, triumphs and failures and confesses to the fears and uncertainties he's dealt with. He explains the surgical instruments he uses and how procedures have changed since he started practicing. And he reflects on the state of his profession and the mysteries of the brain and consciousness. Last year, he retired as the senior consulting neurosurgeon at St. George's Hospital in London, where he practiced for 28 years. He was the subject of the Emmy Award-winning 2007 documentary "The English Surgeon," which followed him in Ukraine, trying to help patients and improve conditions at a rundown hospital. Marsh's book, "Do No Harm," is now out in paperback. Terry spoke to him when it was published in hardback. © 2016 npr
Link ID: 22732 - Posted: 10.08.2016
Emily Badger One of the newest chew toys in the presidential campaign is “implicit bias,” a term Mike Pence repeatedly took exception to in the vice-presidential debate on Tuesday. Police officers hear all this badmouthing, said Mr. Pence, Donald J. Trump’s running mate, in response to a question about whether society demands too much of law enforcement. They hear politicians painting them with one broad brush, with disdain, with automatic cries of implicit bias. He criticized Hillary Clinton for saying, in the first presidential debate, that everyone experiences implicit bias. He suggested a black police officer who shoots a black civilian could not logically experience such bias. “Senator, please,” Mr. Pence said, addressing his Democratic opponent, Tim Kaine, “enough of this seeking every opportunity to demean law enforcement broadly by making the accusation of implicit bias every time tragedy occurs.” The concept, in his words, came across as an insult, a put-down on par with branding police as racists. Many Americans may hear it as academic code for “racist.” But that connotation does not line up with scientific research on what implicit bias is and how it really operates. Researchers in this growing field say it isn’t just white police officers, but all of us, who have biases that are subconscious, hidden even to ourselves. Implicit bias is the mind’s way of making uncontrolled and automatic associations between two concepts very quickly. In many forms, implicit bias is a healthy human adaptation — it’s among the mental tools that help you mindlessly navigate your commute each morning. It crops up in contexts far beyond policing and race (if you make the rote assumption that fruit stands have fresher produce, that’s implicit bias). But the same process can also take the form of unconsciously associating certain identities, like African-American, with undesirable attributes, like violence. © 2016 The New York Times Company
Link ID: 22730 - Posted: 10.08.2016
James Gorman When the leader of a flock goes the wrong way, what will the flock do? With human beings, nobody can be sure. But with homing pigeons, the answer is that they find their way home anyway. Either the lead pigeon recognizes that it has no clue and falls back into the flock, letting birds that know where they are going take over, or the flock collectively decides that the direction that it is taking just doesn’t feel right, and it doesn’t follow. Several European scientists report these findings in a stirring report in Biology Letters titled, “Misinformed Leaders Lose Influence Over Pigeon Flocks.” Isobel Watts, a doctoral student in zoology at Oxford, conducted the study with her advisers, Theresa Burt de Perera and Dora Biro, and with the participation of Mate Nagy, a statistical physicist from Hungary, who is affiliated with several institutions, including Oxford and the Hungarian Academy of Sciences. Dr. Biro, who studies social behavior in primates as well as pigeons, said that the common questions that ran through her work were “about group living and what types of challenges and opportunities it brings.” She and her colleagues at Oxford have pioneered a method of studying flock behavior that uses very-fine-resolution GPS units, which the birds wear in pigeon-size backpacks. The devices record a detailed position for each bird a number of times a second. Researchers in Budapest and Oxford developed software to analyze small movements and responses of every bird in a flock. With this method, the scientists can identify which pigeons are leading the way. They can build a picture of how each bird responds to changes in the flight of other birds. © 2016 The New York Times Company
George Paxinos Many people today believe they possess a soul. While conceptions of the soul differ, many would describe it as an “invisible force that appears to animate us”. It’s often believed the soul can survive death and is intimately associated with a person’s memories, passions and values. Some argue the soul has no mass, takes no space and is localised nowhere. But as a neuroscientist and psychologist, I have no use for the soul. On the contrary, all functions attributable to this kind of soul can be explained by the workings of the brain. Psychology is the study of behaviour. To carry out their work of modifying behaviour, such as in treating addiction, phobia, anxiety and depression, psychologists do not need to assume people have souls. For the psychologists, it is not so much that souls do not exist, it is that there is no need for them. It is said psychology lost its soul in the 1930s. By this time, the discipline fully became a science, relying on experimentation and control rather than introspection. What is the soul? It is not only religious thinkers who have proposed that we possess a soul. Some of the most notable proponents have been philosophers, such as Plato (424-348 BCE) and René Descartes in the 17th century. Plato believed we do not learn new things but recall things we knew before birth. For this to be so, he concluded, we must have a soul. Centuries later, Descartes wrote his thesis Passions of the Soul, where he argued there was a distinction between the mind, which he described as a “thinking substance”, and the body, “the extended substance”. He wrote: © 2010–2016, The Conversation US, Inc.
Link ID: 22692 - Posted: 09.26.2016
By CATHERINE SAINT LOUIS Attention deficit disorder is the most common mental health diagnosis among children under 12 who die by suicide, a new study has found. Very few children aged 5 to 11 take their own lives, and little is known about these deaths. The new study, which included deaths in 17 states from 2003 to 2012, compared 87 children aged 5 to 11 who committed suicide with 606 adolescents aged 12 to 14 who did, to see how they differed. The research was published on Monday in the journal Pediatrics. About a third of the children of each group had a known mental health problem. The very young who died by suicide were most likely to have had attention deficit disorder, or A.D.D., with or without accompanying hyperactivity. By contrast, nearly two-thirds of early adolescents who took their lives struggled with depression. Suicide prevention has focused on identifying children struggling with depression; the new study provides an early hint that this strategy may not help the youngest suicide victims. “Maybe in young children, we need to look at behavioral markers,” said Jeffrey Bridge, the paper’s senior author and an epidemiologist at the Research Institute at Nationwide Children’s Hospital in Columbus, Ohio. Jill Harkavy-Friedman, the vice president of research at the American Foundation for Suicide Prevention, agreed. “Not everybody who is at risk for suicide has depression,” even among adults, said Dr. Harkavy-Friedman, who was not involved in the new research. Yet the new research does not definitively establish that attention deficit disorder and attention deficit hyperactivity disorder, or A.D.H.D., are causal risk factors for suicide in children, Dr. Bridge said. Instead, the findings suggest that “suicide is potentially a more impulsive act among children.” © 2016 The New York Times Company
By DAVID Z. HAMBRICK and ALEXANDER P. BURGOYNE ARE you intelligent — or rational? The question may sound redundant, but in recent years researchers have demonstrated just how distinct those two cognitive attributes actually are. It all started in the early 1970s, when the psychologists Daniel Kahneman and Amos Tversky conducted an influential series of experiments showing that all of us, even highly intelligent people, are prone to irrationality. Across a wide range of scenarios, the experiments revealed, people tend to make decisions based on intuition rather than reason. In one study, Professors Kahneman and Tversky had people read the following personality sketch for a woman named Linda: “Linda is 31 years old, single, outspoken and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in antinuclear demonstrations.” Then they asked the subjects which was more probable: (A) Linda is a bank teller or (B) Linda is a bank teller and is active in the feminist movement. Eighty-five percent of the subjects chose B, even though logically speaking, A is more probable. (All feminist bank tellers are bank tellers, though some bank tellers may not be feminists.) In the Linda problem, we fall prey to the conjunction fallacy — the belief that the co-occurrence of two events is more likely than the occurrence of one of the events. In other cases, we ignore information about the prevalence of events when judging their likelihood. We fail to consider alternative explanations. We evaluate evidence in a manner consistent with our prior beliefs. And so on. Humans, it seems, are fundamentally irrational. But starting in the late 1990s, researchers began to add a significant wrinkle to that view. As the psychologist Keith Stanovich and others observed, even the Kahneman and Tversky data show that some people are highly rational. In other words, there are individual differences in rationality, even if we all face cognitive challenges in being rational. So who are these more rational people? Presumably, the more intelligent people, right? © 2016 The New York Times Company
By Colin Barras Subtract 8 from 52. Did you see the calculation in your head? While a leading theory suggests our visual experiences are linked to our understanding of numbers, a study of people who have been blind from birth suggests the opposite. The link between vision and number processing is strong. Sighted people can estimate the number of people in a crowd just by looking, for instance, while children who can mentally rotate an object and correctly imagine how it might look from a different angle often develop better mathematical skills. “It’s actually hard to think of a situation when you might process numbers through any modality other than vision,” says Shipra Kanjlia at Johns Hopkins University in Baltimore, Maryland. But blind people can do maths too. To understand how they might compensate for their lack of visual experience, Kanjlia and her colleagues asked 36 volunteers – 17 of whom had been blind at birth – to do simple mental arithmetic inside an fMRI scanner. To level the playing field, the sighted participants wore blindfolds. We know that a region of the brain called the intraparietal sulcus (IPS) is, and brain scans revealed that the same area is similarly active in blind people too. “It’s really surprising,” says Kanjlia. “It turns out brain activity is remarkably similar, at least in terms of classic number processing.” This may mean we have a deep understanding of how to handle numbers that is entirely independent of visual experience. This suggests we are all born with a natural understanding of numbers – an idea many researchers find difficult to accept. © Copyright Reed Business Information Ltd.