By Laura Sanders As the curtain lifts at Harrah’s in Las Vegas, magician Mac King walks out on stage in a tacky plaid suit and belts out a goofy “Howdy! I’m Mac King!” He then starts bending minds with more finesse and precision than a Jedi knight. King convinces spectators that he can hook a fish out of thin air, eat it and then spit it back out — intact — into a wine glass. Such skill in manipulating people’s perceptions has earned magicians a new group of spellbound fans: Scientists seeking to learn how the eyes and brain perceive — or don’t perceive — reality. Magicians’ intuitions about human cognition have been passed down, along with their methods for entertaining, for thousands of years. “We as scientists have a lot to learn from the art world,” says Susana Martinez-Conde, of the Barrow Neurological Institute in Phoenix, who studies the neuroscience of visual systems. “If we had been paying attention to magic early on, cognitive neuroscience may have come around much faster.” In an article published in November 2008 in Nature Reviews Neuroscience, Martinez-Conde and other neuroscientists teamed up with famous magicians to argue that magic can be a powerful tool for probing how the human mind sees the world. Using cutting-edge methods to study how the brain and visual systems control perception, scientists are starting to figure out what magicians have known for ages — how your brain can play tricks on you. © Society for Science & the Public 2000 - 2009

Keyword: Attention; Vision
Link ID: 12743 - Posted: 06.24.2010

By Nikhil Swaminathan Senior moments, those pesky instances of not so total recall—forgetting where we left our keys or what we did last weekend—are a subtle but significant part of the aging process. Another effect of growing old: rising blood sugar levels, which typically take off in our late 30s or early 40s as our bodies become less adept at metabolizing glucose in the bloodstream. Now a study has linked these rising levels with momentary forgetfulness, pinpointing exactly where in the brain the aging process acts—a finding that could help the elderly ward off memory lapses. The nature of senior moments led scientists to believe they stem from disruptions in the hippocampus—an area that, among other roles, acts as the brain’s “save” button, allowing us to retain new information. Using functional MRI, researchers looked at the effects of increased blood glucose in the hippocampus of 181 subjects aged 65 or older with no history of dementia. They found that elevated levels impaired function of a section of the hippocampus called the dentate gyrus, which is a “hotspot” of age-related impairment, according to study author Scott Small, a neurologist at Columbia University. Blood glucose is not alone in selectively affecting dentate gyrus performance. A 2007 study co-authored by Small shows that exercise improves its function in both mice and humans. The newer research, he points out, suggests that these positive effects may actually result from the influence of regular exercise on the body’s ability to break down glucose. © 1996-2009 Scientific American Inc

Keyword: Learning & Memory
Link ID: 12742 - Posted: 06.24.2010

by Ewen Callaway A chemical best known for cementing the bond between a mother and her newborn child could also play a part in picking mister (or miss) right. A new study shows that men and women who inhale a whiff of the hormone oxytocin rate strangers as more attractive. When oxytocin courses through our blood, "we are more likely to see people we don't know in a more positive light," says Angeliki Theodoridou, a psychologist at the University of Bristol, UK, who led the new study. This effect adds to the hormone's known role in human relationships. One study found that oxytocin levels spike after new mothers look at or touch their newborns and may help bonding. Other work has hinted at the importance of oxytocin in social situations between adults too. People administered the hormone make overly generous offers in an economic game that measures trust, while men who got a dose of oxytocin proved better at remembering the faces of strangers a day later, compared to subjects who got a placebo. In the latest trial, Theodoridou's team tested 96 men and women in a double-blind placebo-controlled trial. After participants got either a spritz of oxytocin or a placebo, they rated pictures of 48 men and women for attractiveness and 30 for trustworthiness. Her team also tested for mood. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 12741 - Posted: 06.24.2010

by Ewen Callaway A seven-year-old girl with a Y chromosome is providing new clues about a possible "master switch" of maleness. The girl has the normal chromosome count – 46 – and should be male. Other children who have the male sex chromosome but do not appear to be boys have been found to have gene mutations that temper the Y chromosome's effects. However this child doesn't have ambiguous gonads, shrivelled testes or other developmental defects. She instead has a normal vagina, cervix and set of ovaries. A team led by Anna Biason-Lauber, of University Children's Hospital in Zurich, Switzerland, thinks the patient's normalcy is due to mutations in a poorly understood gene on chromosome 17 called CBX2. The child's unique condition might not have been discovered were it not for tests performed before birth to check for major genetic defects, such as an extra copy of chromosome 21 that causes Down's syndrome. Those tests came up negative and indicated the child would be a boy. Gene shut-down When a girl with normal sex organs was born, doctors started scratching their heads. Most females with a Y chromosome have underdeveloped gonads that are prone to developing tumours and usually removed. However, when surgeons operated with the intention of removing the gonads they found normal-looking ovaries in the girl, and took only a tissue sample. This sample, too, looked normal. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 12740 - Posted: 06.24.2010

By Gisela Telis Stare at a waterfall long enough, and nearby stationary objects such as rocks and trees will seem to drift up. The optical illusion is called motion aftereffect, and it may trick more than just your eyes, according to a new study. When subjects watched a stationary stripe on a computer screen after a machine stroked their fingertips, the motion of the stroking created the illusion that the stripe was moving. The discovery demonstrates for the first time a two-way crosstalk between touch and vision, challenging long-held notions of how the brain organizes the senses. In 2000, neuroscientist Christopher Moore, now at the Massachusetts Institute of Technology in Cambridge, noticed that when a vibrating device buzzed a subject's fingertips, the visual motion detector in the brain fired up. But he immediately dismissed the result. At the time, researchers thought that the brain processes each sense--taste, touch, smell, sight, and hearing--separately and that it only later combines them to interpret the world. Over the past 5 years, however, further studies have challenged this picture. Experiments with blind subjects, for example, have found that reading Braille by touch can trigger activity in the brain's visual cortex (ScienceNOW, 8 November 2002). Researchers attributed the phenomenon to the brain rewiring itself to compensate for disability. But Moore and graduate student Talia Konkle wondered if the sight-touch link might lurk in everyone and if one sense might influence the other. © 2009 American Association for the Advancement of Science.

Keyword: Pain & Touch; Vision
Link ID: 12739 - Posted: 06.24.2010

By Tina Hesman Saey In the ongoing battle of the bulge, maybe it is time to fight fat with fat. Three new studies in the April 9 New England Journal of Medicine show that adult humans have brown fat, an energy-burning type of fat previously thought to be found only in animals and human babies. White fat cells store energy in the form of lipids, but brown fat cells burn energy and give off heat. Mice and human babies have pads of brown fat on their backs that help maintain body temperature. Brown fat is activated by cold temperatures. Mice keep the fat throughout life, but brown fat disappears from babies’ backs and many researchers thought adult humans didn’t have brown fat. Or if they did, that it wasn’t important. Now, the new studies demonstrate that brown fat is common in adults and may be important for regulating body weight and blood sugar. But the fat isn’t where people expected to find it. In adults, brown fat is found in the neck, above the collarbone, around the spine and in the abdomen. Ronald Kahn of the Joslin Diabetes Center and Harvard Medical School in Boston and his colleagues examined records from 1,972 people who had PET-CT scans for other reasons. The researchers found evidence of brown fat in 7.5 percent of the women and 3.1 percent of the men. Brown fat was more apparent in people younger than 50, people with healthy blood sugar levels and in lean people. Comparisons with weather records showed the fat was more evident in scans taken when the weather was colder. © Society for Science & the Public 2000 - 2009

Keyword: Obesity
Link ID: 12738 - Posted: 06.24.2010

Pregnant women who suffer from stress are more likely to have a child with asthma, according to research from Children of the 90s study. Researchers working with about 6,000 families in Bristol found anxious mums-to-be were 60% more likely to have a baby who would develop the illness. The findings show 16% of asthmatic children had mothers who reported high anxiety while pregnant. Mothers-to-be who were less stressed had a lower incidence rate. Professor John Henderson, from the Children of the 90s team, said: "Perhaps the natural response to stress which produces a variety of hormones in the body may have an influence on the developing infant and their developing immune system that manifests itself later on." The Children of the 90s study - carried out by the University of Bristol - has been following 14,000 children. They are regularly tested and monitored to see how different lifestyles affect growth, intelligence and health. The aim is to identify ways to optimise the health and development of children. Key findings to come out of the project include left-handed children do less well in tests than their right-handed peers and women who eat oily fish while pregnant have children with better visual development. (C)BBC

Keyword: Stress; Neuroimmunology
Link ID: 12737 - Posted: 04.08.2009

By Victoria Gill Chimpanzees enter into "deals" whereby they exchange meat for sex, according to researchers. Male chimps that are willing to share the proceeds of their hunting expeditions mate twice as often as their more selfish counterparts. This is a long-term exchange, so males continue to share their catch with females when they are not fertile, copulating with them when they are. The team describe their findings in the journal PLoS One. Cristina Gomes and her colleagues, from the Max Planck Institute for Evolutionary Anthropology in Germany, studied chimps in the Tai Forest reserve in Ivory Coast. She and her team observed the animals as they hunted, and monitored the number of times they copulated. "By sharing, the males increase the number of times they mate, and the females increase their intake of calories," said Dr Gomes. "What's amazing is that if a male shares with a particular female, he doubles the number of times he copulates with her, which is likely to increase the probability of fertilising that female." Meat is important for the animals' diet because it is so high in protein. Since female chimps do not usually hunt, "they have a hard time getting it on their own," explained Dr Gomes. The "meat for sex hypothesis" had already been proposed to explain why male chimps might share with females. But previous attempts to record the phenomenon failed, because researchers looked for direct exchanges, where a male shared meat with a fertile female and copulated with her right away. Dr Gomes' team took a new approach. (C)BBC

Keyword: Sexual Behavior; Evolution
Link ID: 12736 - Posted: 04.08.2009

By Stephen L. Macknik and Susana Martinez-Conde Alas! Poor Yorick. I knew him well. A fellow of infinite jest, of most excellent fancy; he hath borne me on his back a thousand times; and now, how abhorred in my afterimage he is! Well… that’s what Hamlet would have said, had he been holding the vintage Pear’s Soap advertisement bearing Yorick’s skull in the accompanying slide, rather than a dug up and rotting Danish cranium. In this antique illusion, you can stare at the X in Yorick’s left eye socket for about 10 to 30 seconds, then look away at a flat surface such as a piece of paper, wall, ceiling or sky, and you will see Yorick’s afterimage as a ghostly apparition. Afterimages such as this one help us to understand how neurons in various areas of the brain adapt to the visual environment. Adaptation, in this case, is the process by which neurons habituate and eventually cease responding to an unchanging stimulus. Once neurons have adapted, it takes a while for them to reset to their previous, unadapted state: it is during this period that we see illusory afterimages. We see afterimages every day: after briefly looking at the sun, at a bright light bulb or after being momentarily blinded by a camera flash, we perceive a temporary dark spot in our field of vision. Vision scientists believe that the adaptation effect producing poor Yorick’s afterimage largely takes place in the neurons of the retina. How can we know? Close your right eye and stare at the X again. Then look at the wall again to see the afterimage, but this time switch back-and-forth between closing one eye and the other. Only the left eye—which was open during the adaptation period—will reveal Yorick’s ghost. © 1996-2009 Scientific American Inc

Keyword: Vision
Link ID: 12735 - Posted: 06.24.2010

By Susan Milius Exposing a bottle-nosed dolphin to a couple of minutes of nearby sonar pinging could cause some temporary hearing impairment, a new test finds. What sonar does to marine mammals has become a hotly debated topic in recent years, as beaked whales and other species have stranded in shallow water and died after naval training exercises in the area. For the first time, researchers have played recordings of actual naval sonar to a marine mammal and tested its hearing after progressive step-ups in intensity over a couple of months, says Aran Mooney of the Woods Hole Oceanographic Institution in Massachusetts. Working with a bottle-nosed dolphin trained in the protocols of hearing tests, Mooney and his colleagues played a series of recordings of sonar pings, building up to an intensity that mimicked a ship some 40 meters away. (The bottle-nosed dolphin was free to swim farther away from the noise. It didn’t, but then again researchers were offering it fish.) After hearing 15 pings at 203 decibels, the animal’s threshold for detecting sounds had shifted up some six decibels, Mooney and his colleagues report online April 7 in Biology Letters. “It’s a rock-concert effect,” Mooney says. After listening to blasting music, fans may notice a cottony quality to their hearing, as if something’s blocking their ears. The effect diminishes in time. And the bottle-nosed dolphin’s hearing also returned to normal typically after about 20 minutes, Mooney reports. © Society for Science & the Public 2000 - 2009

Keyword: Hearing
Link ID: 12734 - Posted: 06.24.2010

By ERIC NAGOURNEY Stroke patients who practice tai chi may improve their balance — reducing the risk of falls, researchers say. Writing in the journal Neurorehabilitation and Neural Repair, the researchers reported improvement in volunteers after as little as six weeks of training. The lead author was Stephanie S. Y. Au-Yeung of Hong Kong Polytechnic University. In earlier research, one of the article’s co-authors, Christina W. Y. Hui-Chan, found that tai chi improved balance among healthy elderly people. For this study, the researchers wanted to see if the same effect would occur among stroke patients. They took 136 people who had a stroke six months or more earlier and divided them into two groups. Over 12 weeks, one group did general exercise, the other a modified version of tai chi. The tai chi group met once a week for an hour, and were asked to practice at home about three hours a week. While the exercise group showed little improvement in balance, the tai chi group made significant gains when they were tested on weight-shifting, reaching and how well they could maintain their stability on a platform that moved like a bus. The benefit of tai chi, the researchers said, is that once the forms are mastered, they can be done without supervision. Copyright 2009 The New York Times Company

Keyword: Stroke; Regeneration
Link ID: 12733 - Posted: 06.24.2010

By DONALD G. McNEIL Jr. Confirming the fears of Somali immigrants in Minneapolis, the Minnesota Health Department agreed Tuesday that young Somali children there appeared to have higher-than-usual rates of autism. Though health officials emphasized that their report was based on very limited data, they concluded that young Somali children appeared to be two to seven times as likely as other children to be in classes for autistic pupils. Dr. Sanne Magnan, the state health commissioner, said the finding was “consistent with the observations by parents,” who have been saying for more than a year that alarming numbers of Somali children born in this country have severe autism. Somalis began immigrating into the area in the 1990s, fleeing civil war in their homeland. The report made no effort to explain why the children had autism. Its authors did not examine children or their medical records. They accepted the diagnoses — some by doctors, some by school evaluators — that admitted children to special-education classes, and they calculated rates for different ethnic groups. They counted only 3- to 4-year-olds, only children in Minneapolis public schools, and only children born in Minnesota. They drew no comparisons with Somalis in other cities. There have been anecdotal reports of higher autism rates among Somalis in some American cities, and no formal studies. A small study in Sweden reported high rates among Somali schoolchildren in Stockholm. Copyright 2009 The New York Times Company

Keyword: Autism
Link ID: 12732 - Posted: 06.24.2010

Heightened activity in an area of the brain that deals with memory may give a subtle early warning of dementia decades later, UK research suggests. It was known that carrying a rogue version of a gene called ApoE4 raised the risk of Alzheimer's disease. Now researchers have linked the same mutation with raised activity in an area of the brain called the hippocampus in people as young as 20. The study appears in Proceedings of the National Academy of Science. The researchers, from Oxford University and Imperial College London, believe over-activity in the hippocampus may effectively wear it out, raising the risk of dementia in later life. They hope their work could be a first step towards developing a simple method to identify people at increased risk of developing dementia. They could then potentially be offered early treatment and lifestyle advice. Carrying one copy of the rogue ApoE4 gene raises the risk of Alzheimer's by up to four times the normal, two copies by up to 10 times. But not everyone with the rogue gene will develop the condition. The latest study used scans to compare brain activity in 36 volunteers aged 20 to 35. In those who carried the rogue gene activity in the hippocampus was consistently raised, even at rest. Researcher Dr Clare Mackay said: "These are exciting first steps towards a tantalising prospect: a simple test that will be able to distinguish who will go on to develop Alzheimer's." (C)BBC

Keyword: Alzheimers
Link ID: 12731 - Posted: 04.07.2009

by Helen Thomson By the time you retire, there's no doubt about it, your brain isn't what it used to be. By 65 most people will start to notice the signs: you forget people's names and the teapot occasionally turns up in the fridge. There is a good reason why our memories start to let us down. At this stage of life we are steadily losing brain cells in critical areas such as the hippocampus - the area where memories are processed. This is not too much of a problem at first; even in old age the brain is flexible enough to compensate. At some point though, the losses start to make themselves felt. Clearly not everyone ages in the same way, so what's the difference between a jolly, intelligent oldie and a forgetful, grumpy granny? And can we improve our chances of becoming the former? Exercise can certainly help. Numerous studies have shown that gentle exercise three times a week can improve concentration and abstract reasoning in older people, perhaps by stimulating the growth of new brain cells. Exercise also helps steady our blood glucose. As we age, our glucose regulation worsens, which causes spikes in blood sugar. This can affect the dentate gyrus, an area within the hippocampus that helps form memories. Since physical activity helps regulate glucose, getting out and about could reduce these peaks and, potentially, improve your memory (Annals of Neurology, vol 64, p 698). © Copyright Reed Business Information Ltd.

Keyword: Alzheimers; Development of the Brain
Link ID: 12730 - Posted: 06.24.2010

by Anil Ananthaswamy Healthy young adults carrying a gene variant that is a major risk factor for the disease seem to have extra activity in brain regions related to memory, even when their brains are at rest. The gene APOE codes for a protein thought to help create, maintain and repair neuronal connections. One variant, epsilon 4, is considered the biggest risk factor for getting Alzheimer's, increasing your risk by up to 4 times if you have one copy and up to 12 if you have two. It is not known exactly how epsilon 4 ups the risk, but in people who carry it and have developed Alzheimer's, the hippocampus, which is involved in memory functions, is usually smaller. To figure out if epsilon 4 influences brain function earlier on in life, Clare Mackay of the University of Oxford and colleagues at Imperial College London scanned the brains of 18 healthy adults with epsilon 4 and 18 controls who did not have the variant. In the scanner, the volunteers spent time performing memory tests and also doing nothing. During the memory task, the epsilon 4 carriers had more activity in the hippocampus compared with controls, even though there was no difference in their performance on the tests, suggesting that their hippocampuses expend more energy to achieve the same result. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers
Link ID: 12729 - Posted: 06.24.2010

By Bruce Bower CHICAGO — Give the chimpanzees living at Uganda’s Toro-Semliki Wildlife Reserve a hand for having the mental moxie to dig water-collection holes along the edge of a river that flows only during rainy months. In fact, give them two hands, because wells dug by these chimps show no evidence of having been fashioned by either right-handers or left-handers, according to anthropologist Linda Marchant of Miami University in Oxford, Ohio. Evidence of ambidexterity in Semliki chimps counters a suggestion from other researchers, based largely on studies of captive animals, that chimps often favor one hand over the other when performing various tasks. If it exists, chimp handedness interests researchers because it may reflect an evolutionary move toward a brain organized more like that of people — with one hemisphere dominating over the other and prompting either right- or left-handedness —than has often been assumed. “We see no signs of handedness among the Semliki chimps, which appears to be the condition in the wild,” said anthropologist and study coauthor William McGrew of the University of Cambridge in England. Marchant presented her team’s new findings on April 3 at the American Association of Physical Anthropologists annual meeting. Rather than excluding hand preferences altogether among wild chimps, findings at Semliki indicate that chimps use both hands equally on physically demanding jobs, such as well digging, remarked Elizabeth Lonsdorf, director of the Lester E. Fisher Center for the Study and Conservation of Apes at Lincoln Park Zoo in Chicago. © Society for Science & the Public 2000 - 2009

Keyword: Laterality; Evolution
Link ID: 12728 - Posted: 06.24.2010

Women given testosterone for a month were no more likely than women not receiving the hormone to engage in risky financial decisions, according to researchers in Sweden. The findings could suggest that women are a safer pair of hands on the stock-market trading floor than men — or throw into doubt earlier findings about the effect of the hormone on men. A spate of recent studies have found correlations between testosterone levels and risky behaviour in men, including one that found that male securities traders with more testosterone in their saliva made riskier financial decisions1. But now a team led by Magnus Johannesson, an economist at the Stockholm School of Economics, has found no such effects in a group of 200 post-menopausal women. The women were administered testosterone, oestrogen or a placebo for four weeks and asked to play a series of economic games that measure the player's propensity to take risks, their trust and their willingness to share resources. In the 'dictator game', for example, a player can decide how much of a pot of money they will share with a charity and how much to keep for themselves. The team thought that the testosterone-taking women would behave more like men, giving less to charity and accepting more risk in an investment game. Yet their results, which are published in the Proceedings of the National Academy of Sciences, revealed no meaningful differences between the women who had taken testosterone or oestrogen and the placebo group2. "My assumptions have changed a lot," Johannesson says. © 2009 Nature Publishing Group

Keyword: Hormones & Behavior; Aggression
Link ID: 12727 - Posted: 06.24.2010

By Claire Thomas How does the brain cope when, several years after having both hands amputated, a person suddenly receives two new hands? Surprisingly well, it seems. In a study out today, researchers provide the most detailed picture yet of how the brain reorganizes itself to accommodate foreign appendages. And in a result that they are still trying to explain, the scientists found that in two such double-hand transplants, the left hand reconnected with the brain more quickly than did the right. A group of French and Australian doctors performed the world's first hand transplant in 1998, and the same team repeated the feat on both hands 2 years later. Studies carried out since then indicate that the brain reorganizes itself in response to these new appendages. However, the work looked only at coarse hand movements that mainly used nontransplanted muscles. Wanting to learn more about how the brain copes with donor hands, cognitive neuroscientist Angela Sirigu of the French National Research Agency in Lyon and colleagues looked at two right-handed men, one age 20 and the other 42, who recently had left and right hand transplants to replace hands amputated following work injuries 3 to 4 years ago. After extensive training, both men are now able to perform a range of complex tasks with the foreign appendages, from dialing a phone number to using tools such as screwdrivers and pliers to rewire an electrical outlet. The researchers found that both men's motor cortexes--the region of the brain responsible for carrying out muscle movement--had reorganized themselves in response to the new hands. After a person loses a hand, the region of the motor cortex that controls hand movement shrinks and rewires itself to control the upper arm, a property called plasticity. But when Sirigu and colleagues used transcranial magnetic stimulation--a technique that employs magnetic fields to excite neurons in the brain--to stimulate specific fragments of the motor cortex, they found that the "hand areas" in the motor cortex of both men had reassumed their original "wiring." © 2009 American Association for the Advancement of Science.

Keyword: Regeneration
Link ID: 12726 - Posted: 06.24.2010

By ANNIE LUBLINER LEHMANN When my husband and I were told that our son Jonah’s autism was “untreatable,” we made up our minds to prove the experts wrong. We were young and energetic, and the developmental gap between 3-year-old Jonah and his peers, while obvious, was not glaring. With no other children to care for at the time, we made helping Jonah the focus of our lives. Every exchange would become a lesson, every experience a tutorial. Jonah cared most about food (and still does), so I’d go to the grocery store with a list and an agenda, hoping to use that passion to teach him essential concepts. I would follow his gaze and point out colors (red apple) and shapes (round cookie). When he turned away from such lessons, despite our most animated efforts, we tried everything else we could think of. Nothing was too difficult or too expensive. We gave him vitamins and restricted his diet. We introduced communication boards and arranged sensory integration therapy. We had him wear headphones to normalize his hearing and tried other snake-oil treatments no thinking person would consider. But each hope was followed by disappointment. We might as well have been chasing butterflies with a torn net. By the time Jonah reached his teens, we were worn out and frustrated, not very far from where we’d started. We faced the specter of hopelessness and a plethora of unanswerable questions. Copyright 2009 The New York Times Company

Keyword: Autism
Link ID: 12725 - Posted: 06.24.2010

By David Dobbs When Helen Mayberg started curing depression by stimulating a previously unknown neural junction box in a brain area called Brod­mann’s area 25—discovered through 20 years of dogged research—people asked her where she was going to look next. Her reaction was, “What do you mean, Where am I going to look next? I’m going to look more closely here!” Her closer look is now paying off. In a series of papers last year, May­berg and several of her colleagues used diffusion tensor imaging (DTI) to reveal the neural circuitry of depression at new levels of precision. This MRI technique illuminates the connective tracts in the brain. For depression, the resulting map may allow a better understanding of what drives the disorder—and much better targeting and patient selection for treatments such as deep-brain stimulation (DBS) that seek to tweak this circuitry. In the early 2000s Mayberg and Wayne C. Drevets, then at Washington University Medical School, separately established that area 25, which appeared to connect several brain regions involved in mood, thought and emotion, is hyperactive in depressed patients. The area’s significance was confirmed when Mayberg and her colleagues at the University of Toronto—neurosurgeon Andres Lazano and psychiatrist Sidney Kennedy—used DBS devices to bring relief to 12 out of 20 intractably depressed patients [see “Turning Off Depression,” by David Dobbs; Scientific American Mind, August/September 2006]. “That confirmed my hypothesis that area 25 is an important crossroads,” Mayberg says. “But exactly what circuits were we affecting?” © 1996-2009 Scientific American Inc.

Keyword: Depression; Brain imaging
Link ID: 12724 - Posted: 06.24.2010