by Amy Barth Two decades ago, neurosurgeon Itzhak Fried of UCLA was stimulating a woman’s brain with electrodes that had been implanted before surgery to treat her epilepsy. He realized his patient was trying to tell him something, and as he bent down to listen, she mumbled that she had a sudden urge to shift her hand. Apparently an electrode had activated the part of the brain’s motor cortex that controlled the woman’s will to move. Fried realized that medical procedures like this one presented a rare scientific opportunity: Patients being examined for neurosurgery allow researchers to investigate the human brain in action, exploring the functions of different regions in precise detail and in real time. These days, surgeons like Fried are increasingly partnering with brain researchers to take advantage of this access. About 30 such collaborations are currently under way. Although noninvasive imaging methods such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) can track activity in the brain, they provide limited resolution. As Caltech neuroscientist Ueli Rutishauser puts it: “fMRI is like viewing a city from space. You can see the brightness of the lights and the number of inhabitants, but not what they’re doing or who is talking to whom. For that, you have to walk the streets yourself.” The visceral exploration of living brain tissue is, in many cases, still the best way to unravel cognitive functions as diverse as language, memory, vision, and movement. Many of these studies piggyback on tests run on epilepsy patients. Sometimes brain scans fail to identify which regions need to be removed to stop epileptic seizures. If so, surgeons may implant electrodes to record neural activity, then keep the patient in the hospital for days or weeks until the next seizure strikes. With the consent of these wired-up patients, Fried and Harvard Medical School neuroscientist Gabriel Kreiman are conducting studies to investigate how the brain encodes visual information.

Keyword: Brain imaging
Link ID: 13921 - Posted: 06.24.2010

by Randy O. Frost and Gail Steketee We could have found the apartment just by following the powerful musty odor that hit us as we stepped out of the elevator. When we got to the door, my guide knocked. No answer. She knocked again, then a third time. Finally, a small voice inside said, “Who’s there?” “It’s Susan, the social worker. We’re here with the cleaning crew. They’re here to clean out your apartment.” “Daniel’s not here,” the voice behind the door told us. “He went to get us breakfast.” “That’s OK. He doesn’t have to be here.” She opened the door a crack, and the door frame moved, almost imperceptibly. Yet it didn’t really move. The world seemed to shift, and I felt off balance for a moment. The door opened a bit wider, and then I saw them: cockroaches, thousands of them, scurrying along the top of the door to get out of the way. The door opened the rest of the way. The apartment was dark, and it took a moment to appreciate what was inside. No floor was visible, only a layer of dirty papers, food wrappers, and urine-stained rags. A rottweiler bolted out of the back to see what was going on. He jumped over a pile of dirty clothes—at least they looked like clothes. From the edge of the door, the massive pile of junk rose precipitously to the ceiling, like a giant sea wave. It could have been part of a landfill: papers, boxes, shopping carts, paper bags, dirty clothing, lamps—anything that could be easily collected from the street or fished out of a Dumpster. It was one solid wall of trash 20 feet deep, all the way to the back of the apartment. There must have been windows on the far wall, but they were darkened by the broken fans, boxes, and clothing covering them. Inside the condo the sweet, pungent odor of insects and rotting food enveloped us. Susan had instructed me to wear old clothes that I could throw out afterward. I was grateful for the advice but wished I’d also had a face mask—the heavy-duty kind.

Keyword: OCD - Obsessive Compulsive Disorder
Link ID: 13920 - Posted: 06.24.2010

By Matt Walker The giggling sounds of a hyena contain important information about the animal's status, say scientists. In the first study to decipher the hyena's so-called "laugh", they have shown that the pitch of the giggle reveals a hyena's age. What is more, variations in the frequency of notes used when a hyena makes a noise convey information about the animal's social rank. Details of the US-based research are published in the journal BMC Ecology. Professor Frederic Theunissen from the University of California at Berkeley, US, and Professor Nicolas Mathevon from the Universite Jean Monnet in St Etienne, France, worked with a team of researchers to study 26 captive spotted hyenas held at a field station at Berkeley. There they recorded the animals' calls in various social interactions, such as when the hyenas bickered over food, and established which elements of each call corresponded to other factors. Last year, the researchers published some provisional results from the study. Now they have confirmed that the pitch of the giggle reveals a hyena's age, while variations in the frequency of notes can encode information about dominant and subordinate status. BBC © MMX

Keyword: Animal Communication; Language
Link ID: 13919 - Posted: 06.24.2010

By Charles Q. Choi Female crayfish send mixed messages during courtship — using urine. The urine that female American signal crayfishes (Pacifastacus leniusculus) spray out triggers courtship behavior in males. The males attempt to mate only after they catch a whiff, experiments revealed, with it driving them into a sexual frenzy. However, as they unleash this seductive aphrodisiac, the females are typically fighting males, researchers found. The males actually use urine as a signal for violence, releasing it when they fight other males. The females essentially issue it as an invitation and challenge. So why send conflicting signals? By stimulating aggression in males, females can best gauge male size and strength, thereby ensuring only the fittest partners will father their offspring, scientists reason. So why use urine? "Most probably because urine provides uncheatable information," said researcher Thomas Breithaupt, a behavioral ecologist at the University of Hull in England. Animals often bluff about their prowess — male Australian slender crayfish (Cherax dispar) often bluff opponents with large claws that aren't actually stronger than normal, for instance. However, urine contains byproducts of physical processes that can serve as vital clues about their fighting power. © 2010 LiveScience.com.

Keyword: Sexual Behavior; Aggression
Link ID: 13918 - Posted: 06.24.2010

By Eric Bland Magnets can alter a person's sense of morality, according to a new report in the Proceedings of the National Academy of Sciences. Using a powerful magnetic field, scientists from MIT, Harvard University and Beth Israel Deaconess Medical Center are able to scramble the moral center of the brain, making it more difficult for people to separate innocent intentions from harmful outcomes. The research could have big implications for not only neuroscientists, but also for judges and juries. "It's one thing to 'know' that we'll find morality in the brain," said Liane Young, a scientist at MIT and co-author of the article. "It's another to 'knock out' that brain area and change people's moral judgments." Before the scientists could alter the brain's moral center, they first had to find it. Young and her colleagues used functional magnetic resonance imaging to locate an area of the brain known as the right temporo-parietal junction (RTPJ) which other studies had previously related to moral judgments. While muscle movement, language and even memory are found in the same place in each individual, the RTPJ, located behind and above the ear, resides in a slightly different location in each person. For their experiment, the scientists had 20 subjects read several dozen different stories about people with good or bad intentions that resulted in a variety of outcomes. © 2010 Discovery Communications, LLC.

Keyword: Emotions
Link ID: 13917 - Posted: 06.24.2010

by Linda Geddes AS FAR as the internet or phone networks go, bad connections are bad news. Not so in the brain, where slower connections may make people more creative. Rex Jung at the University of New Mexico in Albuquerque and his colleagues had found that creativity correlates with low levels of the chemical N-acetylaspartate, which is found in neurons and seems to promote neural health and metabolism. But neurons make up the brain's grey matter - the tissue traditionally associated with thinking power, rather than creativity. So Jung is now focusing his creativity studies on white matter, which is largely made of the fatty myelin sheaths that wrap around neurons. Less myelin means the white matter has a lower "integrity" and transmits information more slowly. Several recent studies have suggested that white matter of high integrity in the cortex, which is associated with higher mental function, means increased intelligence. But when Jung looked at the link between white matter and creativity, he found something quite different. He used diffusion tensor imaging to study the white matter of 72 volunteers. Unlike MRI, which measures tissue volume, DTI measures the direction in which water diffuses through white matter, an indication of its integrity. © Copyright Reed Business Information Ltd.

Keyword: Intelligence; Brain imaging
Link ID: 13916 - Posted: 06.24.2010

By Kristina Rehm John has a few snorts of cocaine, finds he can take it or leave it, and never bothers to take another hit. Jim has a few snorts of cocaine and before he knows it, his whole life revolves around getting more of the white powder, until his job, his marriage, his health are gone. Why? The answer may lie in one of the most exciting neuroscience discoveries of the last fifty years: the finding that new neurons are born in the adult brain. During the past decade we’ve learned a lot about the function of these newborn neurons, revealing their possible role in psychiatric and neurological diseases such as mood disorders, schizophrenia and epilepsy. The promise of this research is extraordinary. We may be on the verge of understanding, treating or even preventing life-crushing brain-based diseases — including one that affects an estimated 23 million Americans: drug and alcohol addiction. In a recent study published in the Journal of Neuroscience, Michele Noonan, a University of Texas neuroscience graduate student in the lab of Amelia Eisch, shows that a lack of neurogenesis, or birth of new neurons, in the adult rat can actually cause drug addiction. Their team blocked neurogenesis in the hippocampus — a seat of memory — with targeted irradiation, and then tested the rats for their ability to become addicted to cocaine. They found that when fewer neurons were born in the irradiated hippocampus, rats were more vulnerable to develop cocaine addiction and were more likely to relapse. This is the strongest evidence yet that there are real biological reasons why some people might be more vulnerable to addiction than others, and gives us a better understanding of the role these little newborn neurons might play in the brain. © 2010 Scientific American,

Keyword: Drug Abuse; Neurogenesis
Link ID: 13915 - Posted: 06.24.2010

by Tim Wogan If a stranger steps on your foot, you'd probably shrug your shoulders and assure him that no harm has been done, even if your toes are throbbing like crazy. But if that stranger instead takes a swing with his fist-successfully or not—most people are unlikely to be so forgiving. Researchers now believe they've demonstrated which part of the brain allows us to make moral judgments of another person's motives, a find that could lead to a greater understanding of Asperger syndrome and other autism spectrum disorders. Scientists already have some clues about how we judge the actions of another person. Previous research using functional magnetic resonance imaging, a method of imaging activity in the brain, has shown that an area just above the right ear called the right temporoparietal junction (RTPJ) receives more blood than usual when we read about people’s beliefs and intentions, particularly if we use the information to judge people negatively. But it's not possible to say from a simple observational study whether the brain activity is actually necessary to make such a judgment or whether making the negative judgment causes this region to become more active. So social neuroscientist Liane Young of the Massachusetts Institute of Technology in Cambridge and colleagues decided to turn off the right temporoparietal junction and see whether people would make different judgments of others' actions. They achieved this using transcranial magnetic stimulation (TMS), a technology that uses a tightly focused magnetic field to temporarily disable individual regions of the brain. © 2010 American Association for the Advancement of Science

Keyword: Attention; Autism
Link ID: 13914 - Posted: 06.24.2010

By Karen Weintraub When the device first came off, her skin was red and raw. It looked like there was a frozen stick of butter stuffed under her flesh. The 57-year-old had just completed an hourlong fat reduction treatment on her abdomen in a Chestnut Hill dermatologist’s office. (Photos, facing page.) For a few minutes, it distended her belly, with the fat beneath frozen and weirdly hard. As her flesh rapidly defrosted, the lumpiness and redness faded. It would be weeks before she knew whether the procedure had made a difference. Such “body contouring’’ is one of the latest trends in dermatology, aimed at getting rid of small pockets of fat without the pain, price, or recovery time of liposuction or other weight-loss surgery. But also without their dramatic results. The suburban Boston patient said an earlier round of treatment had helped her clothes fit better. “Some days you’re good, some days you’re not,’’ she said. The first treatment left her “feeling like the good days,’’ she said. (While insisting she wasn’t embarrassed about getting the procedure, the woman did not want to be identified by name. “A lot of friends do know’’ about it, she said, looking up from a copy of Women’s Health magazine about 45 minutes into the treatment. “My husband knows. I just don’t want 200 friends to know.’’) © 2010 NY Times Co

Keyword: Obesity
Link ID: 13913 - Posted: 06.24.2010

By AMY HARMON When President Obama nominated Ari Ne’eman to the National Council on Disability, many families touched by autism took it as a positive sign. Mr. Ne’eman would be the first person with the disorder to serve on the council. Kent Adams Ari Ne'eman would be the first person with autism on the National Council on Disability. But he has since become the focus of criticism from other advocates who disagree with his view that society ought to concentrate on accepting autistic people, not curing them. A hold has been placed on Mr. Ne’eman’s nomination, which requires Senate confirmation. Whether the hold is related to the criticism of Mr. Ne’eman (pronounced NAY-men) and what it might take to lift it is unclear. But Mr. Ne’eman, the 22-year-old founder of the Autistic Self-Advocacy Network, seems to be a lightning rod for a struggle over how autism will be perceived at a time when an estimated 1 in 100 American children and teenagers are given such a diagnosis. Mr. Ne’eman is at the forefront of a growing movement that describes autism as a form of “neurodiversity” that should be embraced and accommodated, just as physical disabilities have led to the construction of ramps and stalls in public restrooms for people with disabilities. Autism, he and others say, is a part of their identity. But that viewpoint, critics say, represents only those on the autism spectrum who at least have basic communication skills and are able to care of themselves. Copyright 2010 The New York Times Company

Keyword: Autism
Link ID: 13912 - Posted: 06.24.2010

By Katherine Harmon Like many people, rats are happy to gorge themselves on tasty, high-fat treats. Bacon, sausage, chocolate and even cheesecake quickly became favorites of laboratory rats that recently were given access to these human indulgences—so much so that the animals came to depend on high quantities to feel good, like drug users who need to up their intake to get high. A new study, published online March 28 in Nature Neuroscience, describes these rats' indulgent tribulations, adding to research literature on the how excess food intake can trigger changes in the brain, alterations that seem to create a neurochemical dependency in the eater—or user. (Scientific American is part of Nature Publishing Group.) Preliminary findings from the work were presented at the Society for Neuroscience meeting in October 2009. Like many pleasurable behaviors—including sex and drug use—eating can trigger the release of dopamine, a feel-good neurotransmitter in the brain. This internal chemical reward, in turn, increases the likelihood that the associated action will eventually become habitual through positive reinforcement conditioning. If activated by overeating, these neurochemical patterns can make the behavior tough to shake—a result seen in many human cases, notes Paul Kenny, an associate professor in the Department of Molecular Therapeutics at The Scripps Research Institute in Jupiter, Fla., and co-author of the new study. "Most people who are overweight would say, 'I would like to control my weight and my eating,' but they find it very hard to control their feeding behavior," he says. © 2010 Scientific American,

Keyword: Obesity; Drug Abuse
Link ID: 13911 - Posted: 06.24.2010

By Larry O'Hanlon There's a reason why bees can see you while you're still searching for the source of that buzzing noise: Their color vision is five times faster than human vision and among the fastest color vision yet clocked in the animal world. The lightning-fast color vision enables bees to zip through bushes and trees, escape predators, spot each other and otherwise deal with their world in fast forward. The trick to their fast vision is how many "snap shots" per second the color-detecting cells in bumblebees' eyes take and send to their brains. "The limiting factor is how fast the photo receptors can register a change," explained bee vision researcher Peter Skorupski of Queen Mary, University of London. "So we measured the speed directly from the receptor." In a human eye the receptors are the cells in the retina at the back of the eye. "When we see something it seems instantaneous," said Skorupski. "But there's a lot of processing going on under the bonnet. In our case there can be a delay of tenth of a second before you register what you are seeing." The fastest vision known belongs to flies, but that is not color vision, Skorupski explained. "A lot of this has been worked out in flies. Our work was inspired by classic work on flies. That work focused also on finding the connection between the speed of fly vision to the cost of having such amped-up sight, Skorupski explained. © 2010 Discovery Communications, LLC

Keyword: Vision; Evolution
Link ID: 13910 - Posted: 06.24.2010

By Tina Hesman Saey Scientists are discovering how tiny clocks inside each cell can march to the beat of a master drummer in the brain. Chuwy/iStockphoto, illustration by T. Dube Timing is everything. Just ask a comedian, trapeze artist, Romeo and Juliet — or nearly any cell in your body. Ticking away inside almost all cells are tiny clocks composed of protein gears. Scientists have known that these molecular clocks govern the daily rhythms of life, from mealtimes and bedtimes to the rise and fall of hormone levels, body temperature and blood pressure. New research shows that circadian clocks, as the daily timekeepers are known, do more than just control day-to-day schedules. Such clocks, some scientists say, have the potential to play a role in nearly every biological function. Studies of bacteria, rodents and fruit flies suggest that circadian clocks may time processes as diverse as cellular division and aging. “When you start asking, ‘what does the clock control?’ you have to say, ‘everything,’” says Erik Herzog, a biologist at Washington University in St. Louis. Some of the new insights come from studying the brain’s master clock, a pair of structures known as the suprachiasmatic nucleus, or SCN, that set the body’s daily rhythms. Other work, meanwhile, suggests that the SCN is not a single monolithic clock but more a set of interrelated nodes that help coordinate clocks throughout the body. And still other researchers have found that the SCN may not even be the ultimate arbiter of the body’s time, and that other organs control biological rhythms on their own without much, if any, help from the SCN. © Society for Science & the Public 2000 - 2010

Keyword: Biological Rhythms
Link ID: 13909 - Posted: 06.24.2010

Holly Anderson, contributor IT IS common to feel uncomfortable when reading about new neuroscience techniques that seem to encroach on the sacrosanct realm of our hidden inner lives. And it is understandable to feel even more uncomfortable about the notion that our actions are dictated by processes in our brains, calling into question a place for moral responsibility. This discomfort pervades Eliezer Sternberg's new book. In My Brain Made Me Do It, Sternberg dips into philosophy, psychology and neuroscience research as he considers the various evidence that suggests we lack free will and thus a foundation for moral responsibility. Strange cases from psychology and neuroscience pose problems for a naive view of human agency. What if your hand started grabbing things of its own accord? Or if you were compelled to use every tool you found in front of you? Keep some grains of salt handy as you are reading. The tone Sternberg takes to the possibility of widespread acceptance of neurobiological determinism is of the sky-is-falling variety. With over 40,000 practising neuroscientists, it isn't hard to find juicy quotes dismissing the existence of free will, but it is inaccurate to characterise this as the general attitude of the field. Sternberg addresses two related problems throughout the book. The first concerns the wide range of influences on our actions that we are unaware of at any given moment. If an action I take is triggered by unconscious sensory input, am I employing free will? © Copyright Reed Business Information Ltd

Keyword: Attention
Link ID: 13908 - Posted: 06.24.2010

By Andrea Thompson Many pregnant women report being more forgetful as their pregnancy progresses, and new research suggests it could be caused by elevated hormone levels affecting the brain. Previous studies haven't turned up a solid link that could explain maternal memory problems, widely reported on an anecdotal basis. "I think women are interested and sometimes worried about their memory, and whether they're going to get it back if they feel that they've lost some of their cognitive function during pregnancy," said researcher Diane Farrar of the University of Bradford and Bradford Institute for Health Research in England. Farrar and her colleagues set out to test the spatial memory of pregnant women — that's the memory that tells us where we parked the car or set down the keys. The researchers also measured the levels of a set of sex hormones in the pregnant women and had them fill out a questionnaire to judge their mood and level of anxiety. The results for the 23 pregnant women in the study were compared with 24 non-pregnant women. During their second and third trimesters, the pregnant women performed significantly worse than the non-pregnant women on spatial memory tests, the study found. The memory effect still held at three months after birth. © 2010 LiveScience.com.

Keyword: Hormones & Behavior; Learning & Memory
Link ID: 13907 - Posted: 06.24.2010

By John Horgan Of all scientific fields, neuroscience has the greatest potential for revolutionary advances, philosophical and practical. Someday, brain researchers may figure out how precisely the brain encodes thoughts like the ones I’m thinking now. Cracking the neural code could help solve the mind-body problem, ending millennia of pointless metaphysical chitchat. We may finally understand how brains work and why sometimes they don’t. We might even discover truly effective treatments for depression, schizophrenia, bipolar disorder and dementia and chuck our current quasi-therapies. It is because I have such high hopes for neuroscience that I’m so upset by two trends in financing of the field. One involves neuroscience’s growing dependence on the Pentagon, which is seeking new ways to help our soldiers and harm our enemies. For a still-timely overview of neuroweapons research, check out the 2006 book Mind Wars by bioethicist Jonathan Moreno of the University of Pennsylvania. (PR disclosure: I brought Moreno to my school to give a talk on March 10.) Potential neuroweapons include drugs, transcranial magnetic stimulators and implanted brain chips that soup up the sensory capacities and memories of soldiers, as well as brain-scanners and electromagnetic beams that read, control or scramble the thoughts of bad guys. When Moreno was writing his book, neuroscientists were reluctant to talk about their affair with the Pentagon and seemed embarrassed by it. No longer. Last year the National Academy of Sciences published a 136-page report, Opportunities in Neuroscience for Future Army Applications, that makes an unabashed pitch for militarizing brain research. The authors include the neuroluminaries Floyd Bloom of the Scripps Research Institute in La Jolla, Calif., past president of the American Association for the Advancement of Science and editor-in-chief of Science; and Michael Gazzaniga of the University of California at Santa Barbara. Both are members of the U.S. Council on Bioethics.

Keyword: Miscellaneous
Link ID: 13906 - Posted: 06.24.2010

by Anil Ananthaswamy "I THINK therefore I am," said Descartes. Perhaps he should have added: "I act, therefore I think." Our ability to think has long been considered central to what makes us human. Now research suggests that our bodies and their relationship with the environment govern even our most abstract thoughts. This includes thinking up random numbers or deciding whether to recount positive or negative experiences. "Advocates of traditional accounts of cognition would be surprised," says Tobias Loetscher at the University of Melbourne in Parkville, Australia. "They generally consider human reasoning to involve abstract cognitive processes devoid of any connection to body or space." Until recently, the assumption has been that our bodies contribute only to our most basic interactions with the environment, namely sensory and motor processes. The new results suggest that our bodies are also exploited to produce abstract thought, and that even seemingly inconsequential activities have the power to influence our thinking. Clues that our bodies may play a role in thought can be found in the metaphors we use to describe situations, such as "I was given the cold shoulder" or "she has an excellent grasp of relativity". © Copyright Reed Business Information Ltd

Keyword: Attention
Link ID: 13905 - Posted: 06.24.2010

by Dave Munger The recent fatal attack of a SeaWorld trainer by the orca Tilikum has led to renewed questions about how humans should deal with potentially intelligent animals. Was Tilikum’s action premeditated, and how should that possibility influence decisions on the animal’s future treatment? Orcas, like their close relatives, dolphins, certainly seem smart, though researchers debate just how intelligent these cetaceans are and how similar their cognition is to humans. Should we ever treat such creatures like people? For centuries it seemed obvious to most people what separated them from other animals: Humans have language, they use tools, they plan for the future, and do any number of things that other animals don’t seem to do. But gradually the line between “animal” and “human” has blurred. Some animals do use tools; others solve complicated problems. Some can even be taught to communicate using sign language or other systems. Could it be that there isn’t a clear difference separating humans from other life forms? Last week, Brian Switek, a science writer who blogs about biology and paleontology, found a study demonstrating that tool use in chimpanzees isn’t a new phenomenon. For decades, scientists have been observing chimps using sticks and other objects as tools. They have even seen chimps modifying these tools and transporting them for anticipated use in the future. But until recently, there had been no evidence that tool use among chimps had a very long history. Wild chimpanzees in the Tai National Park in Côte d’Ivoire have been observed using stones as hammers and anvils for cracking large nuts. A team led by archaeologist Julio Mercador found evidence that these tools were being used as long as 4300 years ago: Ancient stones shaped similarly to those being used today as tools. Their research was published in PNAS in 2007. ©2005-2009 Seed Media Group LLC

Keyword: Animal Rights; Aggression
Link ID: 13904 - Posted: 06.24.2010

By Claudia Wallis Up until 20 years ago, scientists believed that the human brain was largely mature by puberty. Apparently, they had failed to notice the irrational behavior and flaky thinking of teenagers. Now, of course, we know that the human brain continues to undergo serious restructuring well into the 20s. (See pictures of a diverse group of American teens.) Sophisticated brain-scan studies by Jay Giedd at the National Institute of Mental Health (NIMH) have shown dramatic changes throughout the teenage years as excess gray matter is pruned from the prefrontal cortex — the seat of higher-order thinking and making judgments (like not smoking weed right before your chemistry exam). Meanwhile, behavioral studies have shown what every parent already knows: teens have poor control over impulses and a tendency toward risk taking. Still, relatively little is known about how such changes affect learning or what happens at a biochemical level in the brain as teens go through their addled adolescence. A fascinating study published in the current issue of Science helps fill in a bit of the picture, drawing evidence from that research-friendly fellow mammal, the mouse. The authors, a team from State University of New York Downstate Medical Center, wanted to look at whether the ability to learn is affected by changes in brain chemistry that occur at puberty. They devised a task that was relatively complex (at least for a mouse) and required learning how to avoid a moving platform that delivered a very mild shock. (See the top 10 animal stories of 2009.) "This is higher-order learning, and it takes multiple trials to learn," explains Sheryl Smith, a professor of physiology and pharmacology at Downstate. Prepubescent mice mastered the task quickly. Postpubescent mice also did quite well. But mice in the throes of puberty, which occurs at age 5 weeks, couldn't seem to get it through their furry little heads. © 2010 Time Inc.

Keyword: Development of the Brain
Link ID: 13903 - Posted: 06.24.2010

by Carl Zimmer One day in 2005, a retired building surveyor in Edinburgh visited his doctor with a strange complaint: His mind’s eye had suddenly gone blind. The surveyor, referred to as MX by his doctors, was 65 at the time. He had always felt that he possessed an exceptional talent for picturing things in his mind. The skill had come in handy in his job, allowing MX to recall the fine details of the buildings he surveyed. Just before drifting off to sleep, he enjoyed running through recent events as if he were watching a movie. He could picture his family, his friends, and even characters in the books he read. Then these images all vanished. The change happened shortly after MX went to a hospital to have his blocked coronary arteries treated. As a cardiologist snaked a tube into the arteries and cleared out the obstructions, MX felt a “reverberation” in his head and a tingling in his left arm. He didn’t think to mention it to his doctors at the time. But four days later he realized that when he closed his eyes, all was darkness. Worried, MX paid a visit to Adam Zeman, a neurologist at the Peninsula Medical School in Exeter, England. Zeman was so intrigued by the case that he teamed up with Sergio Della Sala, a cognitive neuroscientist at the University of Edinburgh who specializes in how the brain handles visual information. Neither Zeman nor Della Sala could offer MX a cure for his condition, unfortunately, but they recognized a rare chance to study how the mind’s eye works. Della Sala proposed running a series of exams. MX gave his consent.

Keyword: Vision; Attention
Link ID: 13902 - Posted: 06.24.2010