Chapter 18. Attention and Higher Cognition
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By Kyle Hill You careen headlong into a blinding light. Around you, phantasms of people and pets lost. Clouds billow and sway, giving way to a gilded and golden entrance. You feel the air, thrusted downward by delicate wings. Everything is soothing, comforting, familiar. Heaven. It’s a paradise that some experience during an apparent demise. The surprising consistency of heavenly visions during a “near death experience” (or NDE) indicates for many that an afterlife awaits us. Religious believers interpret these similar yet varying accounts like blind men exploring an elephant—they each feel something different (the tail is a snake and the legs are tree trunks, for example); yet all touch the same underlying reality. Skeptics point to the curious tendency for Heaven to conform to human desires, or for Heaven’s fleeting visage to be so dependent on culture or time period. Heaven, in a theological view, has some kind of entrance. When you die, this entrance is supposed to appear—a Platform 9 ¾ for those running towards the grave. Of course, the purported way to see Heaven without having to take the final run at the platform wall is the NDE. Thrust back into popular consciousness by a surgeon claiming that “Heaven is Real,” the NDE has come under both theological and scientific scrutiny for its supposed ability to preview the great gig in the sky. But getting to see Heaven is hell—you have to die. Or do you? © 2012 Scientific American
Barry Gordon, professor of neurology and cognitive science at the Johns Hopkins University School of Medicine, replies: Forgive your mind this minor annoyance because it has worked to save your life—or more accurately, the lives of your ancestors. Most likely you have not needed to worry whether the rustling in the underbrush is a rabbit or a leopard, or had to identify the best escape route on a walk by the lake, or to wonder whether the funny pattern in the grass is a snake or dead branch. Yet these were life-or-death decisions to our ancestors. Optimal moment-to-moment readiness requires a brain that is working constantly, an effort that takes a great deal of energy. (To put this in context, the modern human brain is only 2 percent of our body weight, but it uses 20 percent of our resting energy.) Such an energy-hungry brain, one that is constantly seeking clues, connections and mechanisms, is only possible with a mammalian metabolism tuned to a constant high rate. Constant thinking is what propelled us from being a favorite food on the savanna—and a species that nearly went extinct—to becoming the most accomplished life-form on this planet. Even in the modern world, our mind always churns to find hazards and opportunities in the data we derive from our surroundings, somewhat like a search engine server. Our brain goes one step further, however, by also thinking proactively, a task that takes even more mental processing. So even though most of us no longer worry about leopards in the grass, we do encounter new dangers and opportunities: employment, interest rates, “70 percent off” sales and swindlers offering $20 million for just a small investment on our part. Our primate heritage brought us another benefit: the ability to navigate a social system. As social animals, we must keep track of who's on top and who's not and who might help us and who might hurt us. To learn and understand this information, our mind is constantly calculating “what if?” scenarios. What do I have to do to advance in the workplace or social or financial hierarchy? What is the danger here? The opportunity? © 2012 Scientific American
Link ID: 17562 - Posted: 12.03.2012
Children who are obese may be more vulnerable to food advertising, a brain scanning study suggests. Food and beverage companies market to children to establish brand recognition, brand preference and loyalty. Previous studies found preschoolers said foods tasted better wrapped in branded packaging than plain packaging and kids were more likely to try to influence their parents' purchases when exposed to ads. Researchers in the U.S. suspected that children who are obese would show greater activation to food logos in the "drive" regions of the brain compared with healthy weight children. Amanda Bruce of the psychology department at the University of Missouri-Kansas City and her colleagues looked at 10 healthy children and 10 obese children aged 10 to 14 using questionnaires measuring self-control and functional magnetic resonance imaging of brain activity. Other corporate logos and blurred images were also tested. Obese children showed more activation in some reward regions of the brain than the healthy weight children when shown food logos. But that wasn't the case for the control regions of the brain. "When shown food logos, obese children showed significantly less brain activation than the healthy weight children in regions association with cognitive control," the study's authors concluded in Friday's issue of The Journal of Pediatrics. "This provides initial neuroimaging evidence that obese children may be more vulnerable to the effects of food advertising." © CBC 2012
By Tanya Lewis A coma patient’s chances of surviving and waking up could be predicted by changes in the brain’s ability to discriminate sounds, new research suggests. Recovery from coma has been linked to auditory function before, but it wasn’t clear whether function depended on the time of assessment. Whereas previous studies tested patients several days or weeks after comas set in, a new study looks at the critical phase during the first 48 hours. At early stages, comatose brains can still distinguish between different sound patterns,. How this ability progresses over time can predict whether a coma patient will survive and ultimately awaken, researchers report. “It’s a very promising tool for prognosis,” says neurologist Mélanie Boly of the Belgian National Fund for Scientific Research, who was not involved with the study. “For the family, it’s very important to know if someone will recover or not.” A team led by neuroscientist Marzia De Lucia of the University of Lausanne in Switzerland studied 30 coma patients who had experienced heart attacks that deprived their brains of oxygen. All the patients underwent therapeutic hypothermia, a standard treatment to minimize brain damage, in which their bodies were cooled to 33° Celsius for 24 hours. De Lucia and colleagues played sounds for the patients and recorded their brain activity using scalp electrodes — once in hypothermic conditions during the first 24 hours of coma, and again a day later at normal body temperature. The sounds were a series of pure tones interspersed with sounds of different pitch, duration or location. The brain signals revealed how well patients could discriminate the sounds, compared with five healthy subjects. © Society for Science & the Public 2000 - 2012
By ANAHAD O'CONNOR A new study of elementary and middle school students has found that those who are the youngest in their grades score worse on standardized tests than their older classmates and are more likely to be prescribed stimulants for attention deficit hyperactivity disorder. The findings suggest that in a given grade, students born at the end of the calendar year may be at a distinct disadvantage. Those perceived as having academic or behavioral problems may in fact be lagging simply as a result of being forced to compete with classmates almost a full year older than them. For a child as young as 5, a span of one year can account for 20 percent of the child’s age, potentially making him or her appear significantly less mature than older classmates. The new study found that the lower the grade, the greater the disparity. For children in the fourth grade, the researchers found that those in the youngest third of their class had an 80 to 90 percent increased risk of scoring in the lowest decile on standardized tests. They were also 50 percent more likely than the oldest third of their classmates to be prescribed stimulants for A.D.H.D. The differences diminished somewhat over time, the researchers found, but continued at least through the seventh grade. The new study, published in the journal Pediatrics, used data from Iceland, where health and academic measures are tracked nationally and stimulant prescription rates are high and on par with rates in the United States. Previous studies carried out there and in other countries have shown similar patterns, even among college students. Copyright 2012 The New York Times Company
Mo Costandi Albert Einstein is considered to be one of the most intelligent people that ever lived, so researchers are naturally curious about what made his brain tick. Photographs taken shortly after his death, but never before analysed in detail, have now revealed that Einstein’s brain had several unusual features, providing tantalizing clues about the neural basis of his extraordinary mental abilities1. While doing Einstein's autopsy, the pathologist Thomas Harvey removed the physicist's brain and preserved it in formalin. He then took dozens of black and white photographs of it before it was cut up into 240 blocks. He then took tissue samples from each block, mounted them onto microscope slides and distributed the slides to some of the world’s best neuropathologists. The autopsy revealed that Einstein’s brain was smaller than average and subsequent analyses showed all the changes that normally occur with ageing. Nothing more was analysed, however. Harvey stored the brain fragments in a formalin-filled jar in a cider box kept under a beer cooler in his office. Decades later, several researchers asked Harvey for some samples, and noticed some unusual features when analysing them. A study done in 1985 showed that two parts of his brain contained an unusually large number of non-neuronal cells called glia for every neuron2. And one published more than a decade later showed that the parietal lobe lacks a furrow and a structure called the operculum3. The missing furrow may have enhanced the connections in this region, which is thought to be involved in visuo-spatial functions and mathematical skills such as arithmetic. © 2012 Nature Publishing Group
by Douglas Heaven What is nine plus six, plus eight? You may not realise it, but you already know the answer. It seems that we unconsciously perform more complicated feats of reasoning than previously thought – including reading and basic mathematics. The discovery raises questions about the necessity of consciousness for abstract thought, and supports the idea that maths might not be an exclusively human trait. Previous studies have shown that we can subliminally process single words and numbers. To identify whether we can unconsciously perform more complicated processing, Ran Hassin at the Hebrew University of Jerusalem, Israel, and his colleagues used a technique called continuous flash suppression. The technique works by presenting a volunteer's left eye with a stimulus – a mathematical sum, say – for a short period of time, while bombarding the right eye with rapidly changing colourful shapes. The volunteer's awareness is dominated by what the right eye sees, so they remain unconscious of what is presented to the left eye. In the team's first experiment, a three-part calculation was flashed to the left eye. This was immediately followed by one number being presented to both eyes, which the volunteer had to say as fast as possible. When the number was the same as the answer to the sum, people were quicker to announce it, suggesting that they had subconsciously worked out the answer, and primed themselves with that number. © Copyright Reed Business Information Ltd.
One cannot travel far in spiritual circles without meeting people who are fascinated by the “near-death experience” (NDE). The phenomenon has been described as follows: Frequently recurring features include feelings of peace and joy; a sense of being out of one’s body and watching events going on around one’s body and, occasionally, at some distant physical location; a cessation of pain; seeing a dark tunnel or void; seeing an unusually bright light, sometimes experienced as a “Being of Light” that radiates love and may speak or otherwise communicate with the person; encountering other beings, often deceased persons whom the experiencer recognizes; experiencing a revival of memories or even a full life review, sometimes accompanied by feelings of judgment; seeing some “other realm,” often of great beauty; sensing a barrier or border beyond which the person cannot go; and returning to the body, often reluctantly. Such accounts have led many people to believe that consciousness must be independent of the brain. Unfortunately, these experiences vary across cultures, and no single feature is common to them all. One would think that if a nonphysical domain were truly being explored, some universal characteristics would stand out. Hindus and Christians would not substantially disagree—and one certainly wouldn’t expect the after-death state of South Indians to diverge from that of North Indians, as has been reported. It should also trouble NDE enthusiasts that only 10−20 percent of people who approach clinical death recall having any experience at all. Copyright 2012 Sam Harris
Women with migraines did not appear to experience a decline in cognitive ability over time compared to those who didn’t have them, according to a nine-year follow up study funded by the National Institutes of Health. The study also showed that women with migraine had a higher likelihood of having brain changes that appeared as bright spots on magnetic resonance imaging (MRI), a type of imaging commonly used to evaluate tissues of the body. "The fact that there is no evidence of cognitive loss among these women is good news," said Linda Porter, Ph.D., pain health science policy advisor in the Office of the Director at the National Institute of Neurological Disorders and Stroke (NINDS), which provided funding for the study. "We’ve known for a while that women with migraine tend to have these brain changes as seen on MRI. This nine-year study is the first of its kind to provide long-term follow-up looking for associated risk." "An important message from the study is that there seems no need for more aggressive treatment or prevention of attacks," said Mark C. Kruit, M.D., Ph.D., one of the principal investigators, and a neuroradiologist from Leiden University Medical Center, the Netherlands, which led the study. Dr. Kruit and associates evaluated MRIs for changes in the white matter, brainstem, and cerebellum that appeared on the scans as bright spots known as hyperintensities. Previous studies have shown an association between such hyperintensities and risk factors for atherosclerotic disease, increased risk of stroke and cognitive decline.
Keyword: Pain & Touch
Link ID: 17488 - Posted: 11.14.2012
By Fergus Walsh Medical correspondent A Canadian man who was believed to have been in a vegetative state for more than a decade, has been able to tell scientists that he is not in any pain. It's the first time an uncommunicative, severely brain-injured patient has been able to give answers clinically relevant to their care. Scott Routley, 39, was asked questions while having his brain activity scanned in an fMRI machine. His doctor says the discovery means medical textbooks will need rewriting. Vegetative patients emerge from a coma into a condition where they have periods awake, with their eyes open, but have no perception of themselves or the outside world. Mr Routley suffered a severe brain injury in a car accident 12 years ago. None of his physical assessments since then have shown any sign of awareness, or ability to communicate. But the British neuroscientist Prof Adrian Owen - who led the team at the Brain and Mind Institute, University of Western Ontario - said Mr Routley was clearly not vegetative. BBC © 2012
By Charles Q. Choi People with schizophrenia often experience the unnerving feeling that outside forces are controlling them. Other times they feel an illusory sense of power over uncontrollable events. Now scientists find these symptoms may arise from disabilities in predicting or recognizing their own actions. The findings suggest new therapies for treating schizophrenia, which afflicts an estimated 1 percent of the world population. To see where this confusion might stem from, researchers tested two ways people are known to link actions and their outcomes. We either predict the effects of our movements or retrospectively deduce a causal connection. Healthy participants and schizophrenic patients were asked to look at a clock and occasionally push a button. Most of the time the button push was followed by a tone. The participants then told researchers what time they had pushed the button and when the tone had occurred. Healthy volunteers reported later times for each button push if it was followed by a tone. This result suggests that awareness of a link between the two events causes people to perceive less time between them. Participants also tended to estimate later button pushes even in the few cases when no tone was emitted, revealing that the subjects were predicting they would hear the sound, says psychiatrist and cognitive neuroscientist Martin Voss of Charité University Hospital and St. Hedwig Hospital in Berlin. © 2012 Scientific American
By SETH S. HOROWITZ HERE’S a trick question. What do you hear right now? If your home is like mine, you hear the humming sound of a printer, the low throbbing of traffic from the nearby highway and the clatter of plastic followed by the muffled impact of paws landing on linoleum — meaning that the cat has once again tried to open the catnip container atop the fridge and succeeded only in knocking it to the kitchen floor. The slight trick in the question is that, by asking you what you were hearing, I prompted your brain to take control of the sensory experience — and made you listen rather than just hear. That, in effect, is what happens when an event jumps out of the background enough to be perceived consciously rather than just being part of your auditory surroundings. The difference between the sense of hearing and the skill of listening is attention. Hearing is a vastly underrated sense. We tend to think of the world as a place that we see, interacting with things and people based on how they look. Studies have shown that conscious thought takes place at about the same rate as visual recognition, requiring a significant fraction of a second per event. But hearing is a quantitatively faster sense. While it might take you a full second to notice something out of the corner of your eye, turn your head toward it, recognize it and respond to it, the same reaction to a new or sudden sound happens at least 10 times as fast. This is because hearing has evolved as our alarm system — it operates out of line of sight and works even while you are asleep. And because there is no place in the universe that is totally silent, your auditory system has evolved a complex and automatic “volume control,” fine-tuned by development and experience, to keep most sounds off your cognitive radar unless they might be of use as a signal that something dangerous or wonderful is somewhere within the kilometer or so that your ears can detect. © 2012 The New York Times Company
by Virginia Morell Figaro may not be as talented an inventor as Leonardo da Vinci, but among Goffin's cockatoos, he's a prodigy. In their natural habitat—the forests of Indonesia these cockatoos have never been seen making or using tools. But researchers report today—that Figaro, a member of a captive colony of the birds in Austria, invents and uses stick tools of his own design. Although toolmaking and use is not uncommon in animals, this type of spontaneous innovation and individual creativity is "exceedingly rare" among nonhuman animals, the scientists note, and opens up many questions about the cognitive skills required. Understanding these processes, they say, may help unlock many of the questions about the evolution of intelligence. Many species of birds, such as woodpecker finches of the Galapagos Islands, ravens, crows, and herons, are natural toolmakers and users. New Caledonian crows are especially talented, shaping bits of wood and stiff palm leaves into spears and hooks to forage for grubs. One captive New Caledonian crow displayed an inventiveness similar to Figaro's by fashioning hooks (a shape she had not previously seen) out of wire. And captive Northern blue jays, which are not tool-users in the wild, have shredded newspaper to use as rakes for retrieving food pellets. Such talents haven't been seen before in cockatoos—and although tool use is seen in many species, innovative tool manufacture is rare. But even if Figaro is a standalone talent among his species, says Frans de Waal, a primatologist at Emory University in Atlanta, the discovery of such skills in even one individual shows that "general intelligence can lead to innovative behavior." Inventiveness is thus not tied to some type of mental specialization, such as being a natural tool-user, as has been argued previously, he explains. © 2010 American Association for the Advancement of Science.
By ANDREW SOLOMON Drew Petersen didn’t speak until he was 3½, but his mother, Sue, never believed he was slow. When he was 18 months old, in 1994, she was reading to him and skipped a word, whereupon Drew reached over and pointed to the missing word on the page. Drew didn’t produce much sound at that stage, but he already cared about it deeply. “Church bells would elicit a big response,” Sue told me. “Birdsong would stop him in his tracks.” Sue, who learned piano as a child, taught Drew the basics on an old upright, and he became fascinated by sheet music. “He needed to decode it,” Sue said. “So I had to recall what little I remembered, which was the treble clef.” As Drew told me, “It was like learning 13 letters of the alphabet and then trying to read books.” He figured out the bass clef on his own, and when he began formal lessons at 5, his teacher said he could skip the first six months’ worth of material. Within the year, Drew was performing Beethoven sonatas at the recital hall at Carnegie Hall. “I thought it was delightful,” Sue said, “but I also thought we shouldn’t take it too seriously. He was just a little boy.” On his way to kindergarten one day, Drew asked his mother, “Can I just stay home so I can learn something?” Sue was at a loss. “He was reading textbooks this big, and they’re in class holding up a blowup M,” she said. Drew, who is now 18, said: “At first, it felt lonely. Then you accept that, yes, you’re different from everyone else, but people will be your friends anyway.” Drew’s parents moved him to a private school. They bought him a new piano, because he announced at 7 that their upright lacked dynamic contrast. “It cost more money than we’d ever paid for anything except a down payment on a house,” Sue said. When Drew was 14, he discovered a home-school program created by Harvard; when I met him two years ago, he was 16, studying at the Manhattan School of Music and halfway to a Harvard bachelor’s degree. © 2012 The New York Times Company
By Laura Sanders Devoid of any external time cues, monkeys can still tell time. Animals learned to move their eyeballs once every second, a completely internal timing feat made possible by the rhythmic behavior of small groups of nerve cells, researchers propose online October 30 in PLOS Biology. Time is often measured with clues from the environment, says study coauthor Geoffrey Ghose of the University of Minnesota in Minneapolis. A quick glance at a clock indicates that your meeting will start soon, and a look outside at a low sun tells you that it’s time to leave work. But some time-telling abilities rely on purely internal processes — just a feeling that minutes, hours or days have ticked by, Ghose says. Ghose and Blaine Schneider, also of the University of Minnesota, studied this internal sensation of time by creating a situation in which two monkeys had to generate their own pattern without any outside help. The animals were trained to switch their gaze rhythmically between a red dot and a blue dot on a computer screen once every second, a job that looks like “they’re watching an extremely boring tennis match,” Ghose says. After a while, the monkeys got good, on average just tens of milliseconds off their tempo. Meanwhile, the researchers used electrodes to eavesdrop on the behavior of neurons in a part of the brain called the lateral intraparietal area. Earlier monkey studies found that neurons there build up activity with time, firing messages more and more frequently as the milliseconds tick by. © Society for Science & the Public 2000 - 2012
by Elizabeth Norton The ability to recognize faces is so important in humans that the brain appears to have an area solely devoted to the task: the fusiform gyrus. Brain imaging studies consistently find that this region of the temporal lobe becomes active when people look at faces. Skeptics have countered, however, that these studies show only a correlation, but not proof, that activity in this area is essential for face recognition. Now, thanks to the willingness of an intrepid patient, a new study provides the first cause-and-effect evidence that neurons in this area help humans recognize faces—and only faces, not other body parts or objects. An unusual collaboration between researchers and an epilepsy patient led to the discovery. Ron Blackwell, an engineer in Santa Clara, California, came to Stanford University in Palo Alto, California, in 2011 seeking better treatment for his epilepsy. He had suffered seizures since he was a teenager, and at age 47, his medication was becoming less effective. Stanford neurologist Josef Parvizi suggested some tests to locate the source of the seizures—and also suggested that it might be possible to eliminate the seizures by surgically destroying a tiny area of brain tissue where they occurred. Parvizi used electrodes placed on Blackwell's scalp to trace the seizures to the temporal lobe, about an inch above Blackwell's right ear. Then, surgeons placed more electrodes on the surface of Blackwell's brain, near the suspect point of origin in the temporal lobe. Parvizi stimulated each electrode in turn with a mild current, trying to trigger Blackwell's seizure symptoms under safe conditions. "If we get those symptoms, we know that we are tickling the seizure node," he explains. © 2010 American Association for the Advancement of Science.
Link ID: 17414 - Posted: 10.24.2012
By Maria Konnikova I don’t remember if I had any problems paying attention to Jane Austen’s Mansfield Park when I first read it. I doubt it, though. I devoured all of my Austen in one big gulp, book after book, line after line, sometime around the eighth grade. My mom had given a huge, bright blue hardcover, with text as small as the book was weighty, that contained the Jane Austen oeuvre from start to finish. And from start to finish I went. I’ve since revisited most of the novels—there’s only so much you retain, absorb, and process on a thirteen-year-old’s reading binge—but Mansfield Park hasn’t fared quite as well as some of the others. I’m not sure why. I’ve just never gone back. Until a few weeks ago, that is, when I saw that this somewhat neglected (and often frowned upon) novel had been made the center of an intriguing new study of reading and attention. “This is your brain on Jane Austen,” rang the headline. Oh, no, not another one, went my head. It seems like every day, we get another “your brain on…” announcement, and at this point, an allergic reaction seems in order. This one, however, proved to be different. It’s not about your brain on Jane Austen. Not really. It’s about a far more interesting question: can our brains pay close attention in different ways? The neural correlates of attention are a hot research topic—and with good reason. After all, with the explosion of new media streams, new ways of digesting material, new ways of interacting with the world, it would make sense for us to be curious about how it all affects us at the most basic level of the brain. Usually, though, the research deals with the differences between paying attention, like really paying attention, and not paying attention all that much, be it because of increased cognitive load or other forms of multitasking or divided attention. © 2012 Scientific American
Link ID: 17409 - Posted: 10.23.2012
by Sara Reardon We talk to ourselves all day, whether it's convincing ourselves to get out of bed, or avoid that second piece of cake. But this internal voice uses a lot of brainpower. People who have to concentrate on resisting an addiction appear to sacrifice this ability in order to conserve brainpower for other tasks. The average person can juggle about four mental tasks at any time, says Monica Faulkner of Johns Hopkins University in Baltimore. How much you can multitask is related to working memory. With the assumption that recovering addicts must think constantly about their addiction, Faulkner and her colleagues wondered whether this comes at the cost of using up one of those four "slots", possibly impairing their overall working memory. Faulkner and Cherie Marvel, also of Johns Hopkins, recruited six people who had never used drugs and six recovering from a heroin addiction who were taking methadone to help. They showed the volunteers an image, either of a word, a Chinese character, or a pattern. They then waited six seconds, and showed the volunteers a second image. During those six seconds, the researchers recorded the volunteers' brain activity using functional magnetic resonance imaging (fMRI). The volunteers' task was to press a button if the second image matched the first. The people recovering from addiction took a few hundred milliseconds longer than the controls to determine whether they had seen the images previously. But the more interesting result came from the pattern of activity in their brains throughout the 6 second window. © Copyright Reed Business Information Ltd.
By Janet Raloff Carbon dioxide has been vilified for decades as a driver of global warming. A new study finds signs that CO2, exhaled in every breath, can exert an equally worrisome threat — impaired cognition — in nearly every energy-efficient classroom, meeting hall or office space. The work assessed decision-making in 22 healthy young adults. Their performance on six of nine tests dropped notably when researchers raised indoor carbon dioxide levels to 1,000 parts per million from a baseline of 600 ppm. On seven tests, performance fell substantially more when the room’s CO2 was boosted to 2,500 ppm, scientists report in a paper to be published in Environmental Health Perspectives. These data are surprising, says Roger Hedrick of Architectural Energy Corp. in Boulder, Colo., because “1,000 ppm of CO2 used to be considered a benchmark of good ventilation.” Hedrick, an environmental engineer, chairs the committee that drafts commercial ventilation standards through the American Society of Heating, Refrigerating, & Air-Conditioning Engineers. Carbon dioxide levels are often substantially higher in buildings than the 350 to 400 ppm typically found outdoors. Indoor values of 600 ppm are considered very good. But depending on how many people inhabit a room and how many times per hour its air is exchanged with outdoor air through ventilation, “there are plenty of buildings where you could easily see 2,500 ppm of CO2 — or close to it — even with ventilation designs that are fully compliant with current standards,” Hedrick says. © Society for Science & the Public 2000 - 2012
Keyword: Learning & Memory
Link ID: 17380 - Posted: 10.17.2012
by Clare Wilson Why does making direct eye contact with someone give you that feeling of a special connection? Perhaps because it excites newly discovered "eye cells" in the amygdala, the part of the brain that processes emotions and social interactions. This new type of neuron was discovered in a Rhesus macaque. If humans have these neurons too, it may be that they are impaired in disorders such as autism and schizophrenia, which affect eye contact and social interactions. Katalin Gothard, a neurophysiologist at the University of Arizona in Tucson, and her team placed seven electrodes in the amygdala of a Rhesus macaque. The electrodes, each one-tenth the thickness of a human hair, allowed them to record activity in individual neurons as the macaque watched a video featuring another macaque. All the while, the team also tracked the macaque's gaze. Out of the 151 neurons the researchers could distinguish, 23 fired only when the macaque was looking at the eyes of the monkey in the video. Of these neurons, which the team call "eye cells", four fired more when the monkey in the video appeared to be gazing back at the laboratory macaque, as if the two animals were making eye contact. "These are cells that have been tuned by evolution to look at the eye, and they extract information about who you are, and most importantly, are you making eye contact with me," says Gothard. Other eye cells fired depending on whether the monkey in the video was behaving in a friendly, aggressive or neutral manner, but not in response to eye contact. © Copyright Reed Business Information Ltd.
Link ID: 17377 - Posted: 10.17.2012