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Scientists map brain's wiring diagram
Swiss and American researchers have drawn up the first high-resolution map of how some of the most important fibres in the human brain communicate... Swiss and American researchers have drawn up the first high-resolution map of how some of the most important fibres in the human brain... more
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Resuscitation technique after brain injury may do more harm than good
The current standard practice of giving infants and children 100 percent oxygen to prevent brain damage caused by oxygen deprivation may actually inflict additional harm, researchers at UT Southwestern Medical Center have found.
Brain damage caused by oxygen deprivation, known as hypoxic-ischemic brain injury, is one of the most common causes of death and long-term neurological damage among infants and children. This can happen during birth trauma, near drowning and other crises.
The UT Southwestern researchers found that mice treated with less than a minute of 100 percent oxygen after a hypoxic-ischemic brain injury suffered far greater rates of brain-cell death and coordination problems similar to cerebral palsy than those allowed to recover with room air.
"This study suggests 100 percent oxygen resuscitation may further damage an already compromised brain," said Dr. Steven Kernie, associate professor of pediatrics and developmental biology and senior author of the study, which appears in the July issue of the Journal of Cerebral Blood Flow & Metabolism.
Most of the damage involved cells that create myelin, a fatty substance that insulates nerve cells and allows them to transmit electrical signals quickly and efficiently. Infants have much less myelin than adults; as myelin develops in children they become more coordinated. Areas of the brain with dense areas of myelin appear white, hence the term "white matter."
"Patients with white-matter injuries develop defects that often result in cerebral palsy and motor deficits," Dr. Kernie said.
Myelin comes from cells called glial cells, or glia, which reach out and wrap part of their fatty membranes around the extensions of nerve cells that pass electrical signals. The brain creates and renews its population of glial cells from a pool of immature cells that can develop into mature glia.
In their study, the researchers briefly deprived mice of oxygen, then gave them either 100 percent oxygen or room air, which contains about 21 percent oxygen, 78 percent nitrogen and 1 percent other gases.
After 72 hours, mice given 100 percent oxygen fared worse than those given room air. For example, they experienced a more disrupted pattern of myelination and developed a motor deficit that mimicked cerebral palsy.
The population of immature glial cells also diminished, suggesting that the animals would have trouble replacing the myelin in the long term.
"We wanted to determine whether recovery in 100 percent oxygen after this sort of brain injury would exacerbate neuronal injury and impair functional recovery, and in these animals, it did impair recovery," Dr. Kernie said. "Our research shows even brief exposure to 100 percent oxygen during resuscitation actually worsens white-matter injuries."
Dr. Kernie said adding pure oxygen to the damaged brain increases a process called oxidative stress, caused by the formation of highly reactive molecules. The researchers found, however, that administering an antioxidant, which halts the harmful oxidation process, reversed the damage in the mice given 100 percent oxygen.
"Further research is needed to determine the best possible concentration of oxygen to use for optimal recovery and to limit secondary brain injury," Dr. Kernie said. "Research is now being done to determine the best way to monitor this sort of brain damage in humans so we can understand how it correlates to the mouse models. There are many emerging noninvasive technologies that can monitor the brain." The current standard practice of giving infants and children 100 percent oxygen to prevent brain damage caused by oxygen deprivation m... more -
Studies show the value of not over-thinking a decision
Fishing in the stream of consciousness, researchers now can detect our intentions and predict our choices before we are aware of them ourselves. The brain, they have found, appears to make up its mind 10 seconds before we become conscious of a decision -- an eternity at the speed of thought. Fishing in the stream of consciousness, researchers now can detect our intentions and predict our choices before we are aware of them ... more
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The power of the itch
So strong, she scratched through her skull and into her brain...
'"Scratching is one of the sweetest gratifications of nature, and as ready at hand as any,” Montaigne wrote. “But repentance follows too annoyingly close at its heels.” For M., certainly, it did: the itching was so torturous, and the area so numb, that her scratching began to go through the skin. At a later office visit, her doctor found a silver-dollar-size patch of scalp where skin had been replaced by scab. M. tried bandaging her head, wearing caps to bed. But her fingernails would always find a way to her flesh, especially while she slept.
One morning, after she was awakened by her bedside alarm, she sat up and, she recalled, “this fluid came down my face, this greenish liquid.” She pressed a square of gauze to her head and went to see her doctor again. M. showed the doctor the fluid on the dressing. The doctor looked closely at the wound. She shined a light on it and in M.’s eyes. Then she walked out of the room and called an ambulance. Only in the Emergency Department at Massachusetts General Hospital, after the doctors started swarming, and one told her she needed surgery now, did M. learn what had happened. She had scratched through her skull during the night—and all the way into her brain.'
Gotta love the New Yorker! So strong, she scratched through her skull and into her brain... ... more -
Brain scientists discover why adventure feels good
Scientists have identified a primitive area of the brain that makes us adventurous -- a finding which may help explain why people routinely fall for "new" products when shopping.
Using brain scans to measure blood flow, British researchers discovered that a brain region known as the ventral striatum was more active when subjects chose unusual objects in controlled tests.
The ventral striatum is involved in processing rewards in the brain through the release of neurotransmitters like dopamine.
Scientists believe the existence of this age-old reward mechanism indicates there is an evolutionary advantage in sampling the unknown.
"Seeking new and unfamiliar experiences is a fundamental behavioral tendency in humans and animals. It makes sense to try new options as they may prove advantageous in the long run," said Bianca Wittmann of the Wellcome Trust Centre for Neuroimaging at University College London.
Being daring, however, also carries risks. Some choices could be dangerous and, in the modern world, selecting the new may, for instance, make consumers susceptible to marketing hype.
The positive feedback system in the brain could also contribute to some common vices.
"In humans, increased novelty-seeking may play a role in gambling and drug addiction, both of which are mediated by malfunctions in dopamine release," said Nathaniel Daw, now at New York University, who also worked on the study. Scientists have identified a primitive area of the brain that makes us adventurous -- a finding which may help explain why people rout... more -
Sense of adventure loctated in brain
Sophisticated scans showed the region, located in a primitive area of the brain, is activated when people choose unfamiliar options.
The researchers believe this suggests that taking a chance is an ancient human trait that may have given humans an evolutionary advantage.
The University College London study features online in the journal Neuron.
It makes sense to try new options as they may prove advantageous in the long run
Dr Bianca Wittmann
University College London
The research took place at UCL's Wellcome Trust Centre for Neuroimaging.
Volunteers were shown a selection of images with which they had already been made familiar.
Each card had a unique probability of reward attached to it and, over the course of the experiment, the volunteers would be able to work out which selection would provide the highest rewards.
However, when unfamiliar images were introduced the researchers found that volunteers were more likely to take a chance and select one of these options than continue with their familiar - and arguably safer - option.
Using fMRI scanners, which measure blood flow in the brain to highlight which areas are most active, the researchers showed that when the subjects selected an unfamiliar option an area of the brain known as the ventral striatum lit up, indicating that it was more active.
The ventral striatum is in one of the evolutionarily primitive regions of the brain - suggesting that the process can be advantageous and will be shared by many animals.
Lead researcher Dr Bianca Wittmann said: "Seeking new and unfamiliar experiences is a fundamental behavioural tendency in humans and animals.
"It makes sense to try new options as they may prove advantageous in the long run.
"For example, a monkey who chooses to deviate from its diet of bananas, even if this involves moving to an unfamiliar part of the forest and eating a new type of food, may find its diet enriched and more nutritious."
Potential for exploitation
The researchers believe that making a new choice that turns out to be beneficial stimulates release of mood-changing chemicals such as dopamine, which make it more likely that we will continue to be adventurous in the future.
However, the researchers said that making new choices was often a fruitful strategy and also potentially made us more vulnerable to exploitation - for instance by the advertising industry.
Dr Wittmann said: "I might have my own favourite choice of chocolate bar, but if I see a different bar repackaged, advertising its 'new, improved flavour', my search for novel experiences may encourage me to move away from my usual choice.
"This introduces the danger of being sold 'old wine in a new skin' and is something that marketing departments take advantage of."
Professor Nathaniel Daw, now at New York University, who also worked on the study, said rewarding the brain for novel choices could have a more serious side effect.
"In humans, increased novelty-seeking may play a role in gambling and drug addiction, both of which are mediated by malfunctions in dopamine release."
Professor Seth Grant, of the University of Cambridge's Sanger Institute, said the ability to recognise novelty pre-dated the evolution of the striatum, as it had been identified in primitive invertebrates, such as the octopus, which do not have the structure.
However, he said it was probable that the striatum had helped more sophisticated species, including man, to refine the ability.
Sophisticated scans showed the region, located in a primitive area of the brain, is activated when people choose unfamiliar options. ... more -
Attachment Issues?
"Mankind’s inner chimpanzee refuses to let go. This matters to everything from economics to law.
The endowment effect was controversial for years. The idea that a squishy, irrational bit of human behaviour could affect the cold, clean and rational world of markets was a challenge to neoclassical economists. Their assumption had always been that individuals act to maximize their welfare (the defining characteristic of economic man, or Homo economicus). The value someone puts on something should not, therefore, depend on whether he actually owns it. But the endowment effect has been seen in hundreds of experiments, the most famous of which found that students were surprisingly reluctant to trade a coffee mug they had been given for a bar of chocolate, even though they did not prefer coffee mugs to chocolate when given a straight choice between the two.
The endowment effect has nothing to do with wealth or transaction costs. Not even emotional attachment, whatever that means, can really be called in as an explanation, since the effect is both instantaneous and sometimes felt even by those who buy and sell for a living.
. . .
To put flesh on the idea, Dr Jones and Dr Brosnan have been trying to overcome Smith’s observation by training chimpanzees to trade. In 2006 Keith Chen of Yale University showed that capuchin monkeys could learn to do so, and also seemed to exhibit the endowment effect. Chimps, it turns out, can manage to truck too. In the chimp study, tubes of peanut butter and frozen juice bars were used. Both treats were designed to be difficult to eat quickly. This makes it possible for animals that would otherwise consume any food they were given at the first opportunity at least to consider the idea of an exchange.
When presented with a choice, 60% of the chimps preferred peanut butter to juice. However, when they were endowed with peanut butter, 80% of them chose to keep it instead of exchanging it for juice. It was as if the peanut butter became more valuable as soon as it was possessed. And an opposite endowment effect was observed when the chimps were given juice.
All in all, the rational conclusion is that humans are irrational animals."
-economist.com
http://www.economist.com/science/displaystory.cfm?story...
"Mankind’s inner chimpanzee refuses to let go. This matters to everything from economics to law. ... more -
Sexercise - Fitness is freedom
Be more attractive and desirable... Exercise and learn confidence, then have adventurous inventive energetic sex - - -
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mind your mind
if your brain got a D- on its last report card. try out these suggested mental medicines
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Brain Surgeons Don't Hold Cellphones To Their Ears
Young people would be at greatest risk for brain cancer because of a lifetime of exposure if they start using cell phones early.
The doctors use an earpiece. Young people would be at greatest risk for brain cancer because of a lifetime of exposure if they start using cell phones early. ... more -
Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School | ...
"The brain is an amazing thing. Most of us have no idea what’s really going on inside our heads. Yet brain scientists have uncovered details every business leader, parent, and teacher should know." "The brain is an amazing thing. Most of us have no idea what’s really going on inside our heads. Yet brain scientists have uncovered d... more
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Meditation found to increase brain size
People who meditate grow bigger brains than those who don't. Researchers at Harvard, Yale, and the Massachusetts Institute of Technology have found the first evidence that meditation can alter the physical structure of our brains. Brain scans they conducted reveal that experienced meditators boasted increased thickness in parts of the brain that deal with attention and processing sensory input.
In one area of gray matter, the thickening turns out to be more pronounced in older than in younger people. That's intriguing because those sections of the human cortex, or thinking cap, normally get thinner as we age.
Meditators did Buddhist "insight meditation," which focuses on whatever is there, like noise or body sensations. It doesn't involve "om," other mantras, or chanting.
"The goal is to pay attention to sensory experience, rather than to your thoughts about the sensory experience," Lazar explains. "For example, if you suddenly hear a noise, you just listen to it rather than thinking about it. If your leg falls asleep, you just notice the physical sensations. If nothing is there, you pay attention to your breathing." Successful meditators get used to not thinking or elaborating things in their mind.
People who meditate grow bigger brains than those who don't. Researchers at Harvard, Yale, and the Massachusetts Institute of Technolo... more -
Helmet Controls Toy Cars Via Brain Waves
German scientists in Braunschweig have developed a helmet that can control model cars using only brain waves, opening exciting new possibilities for people with physical disabilities.
The so-called Brain-Computer Interface is based on the classic electroencephalogram (EEG) already widely used in medicine to measure electrical brain activity. Minute changes in voltage on the surface of the head are converted in signals by a computer that can then control the movement of an object such as a model car.
"The dream of a simple interface between brain and machine has come true," said Professor Meinhard Schilling, who believes the helmet will be used both for medical diagnostic work and for controlling wheelchairs and prostheses. German scientists in Braunschweig have developed a helmet that can control model cars using only brain waves, opening exciting new pos... more -
Why Brain Surgeons Are Avoiding Cell Phones
Last week, three prominent neurosurgeons told CNN interviewer Larry King that they did not hold cell phones next to their ears. Dr. Keith Black, Dr. Vini Khurana, and CNN’s chief medical correspondent, Dr. Sanjay Gupta all maintained that the practice could be unsafe.
Along with Senator Edward M. Kennedy’s recent diagnosis of a glioma, a type of tumor that critics have long associated with cell phone use, the doctors’ remarks have helped reignite the debate about cell phones and cancer.
(End of excerpt)
Full story at link
Sources:
The New York Times
http://www.nytimes.com/2008/06/03/health/03well.html?_r...
Mercola.com
http://articles.mercola.com/sites/articles/archive/2008...
Last week, three prominent neurosurgeons told CNN interviewer Larry King that they did not hold cell phones next to their ears. Dr. Ke... more -
Wired to be Gay
Scientists at the famous Karolinska Institutet in Stockholm have discovered that the brains of homosexual men and women are structured in the same way as the brains of straight people of their opposite gender. This study has also determined that this basic structural difference of the brains of homosexual people develops in the fetal stage, which means that homosexuals and lesbians were born that way. This will of course disappoint the rabid homphobes. Scientists at the famous Karolinska Institutet in Stockholm have discovered that the brains of homosexual men and women are structured... more
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Lab clones cancer-sniffing dogs
From the report: A South Korean biotech company on Monday unveiled four Labrador retriever puppies skilled at sniffing out patients with cancer.
AMAZING! I had no idea cancer smelled! From the report: A South Korean biotech company on Monday unveiled four Labrador retriever puppies skilled at sniffing out patients wi... more -
Gay men and straight women share brain detail!
From the report: Gay men and straight women share some characteristics in the area of the brain responsible for emotion, mood and anxiety, researchers said on Monday in a study highlighting the potential biological underpinning of sexuality. From the report: Gay men and straight women share some characteristics in the area of the brain responsible for emotion, mood and anxi... more
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New views of human intelligence
"Intelligence - the dark secret of American social science and education - is coming out of the closet. Once intelligence was perceived as a narrow group of mental abilities, those measurable by an I.Q. test. But according to that view great groups of the population turned out to be not very smart or educable ..."
By Marie Winn "Intelligence - the dark secret of American social science and education - is coming out of the closet. Once intelligence was perceive... more -
PAOMNNEHAL PWEOR OF THE HMUAN MNID
If you can read this title then you will know what this is about. The amazing power of the human mind!
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McCain's fossilized brain
John McCain is old and, as several news outlets have reported, he's only getting older. This wouldn't be a problem if his opponent in the general election were equally chronologically gifted. But Barack Obama is one of the youngest Democratic nominees ever. If he won, he'd be the third-youngest U.S. president. The contrast is stark.
As everyone with a grandparent knows, certain types of memory are affected by aging. Episodic memory—the ability to remember things that happened to you—declines. Same for prospective memory, or the ability to remember lists or agendas. You could argue these skills are less essential for a president, who has speechwriters to produce anecdotes and handlers to keep his schedule. But age also affects working memory, which we use to process, sort, and recall information on the fly. Mental arithmetic, for example, requires a good working memory. Fortunately, presidents have calculators. But working memory also translates into debating skills—the better your short-term retention, the better you can rebut your opponent's arguments.
Oldsters show fewer deficits in semantic memory, which includes vocabulary and general knowledge. So while McCain's ability to synthesize facts into a compelling argument might degrade over time, his verbal arsenal is likely to grow. Semantic memory generally peaks in the sixth decade of life and doesn't decline until the ninth. Similarly, behaviors that are considered overlearned—actions you repeat over and over, like driving a car or saying that cutting taxes raises revenue—are less easily forgotten.
An elder president might show some other cognitive symptoms, too. Aging is known to affect our ability to suppress an instinctual response to a given stimulus. A famous example is the "Stroop interference" test. Imagine you're looking at the word blue written in red ink. Now say the name of the color of the ink. Your instinct is probably to say blue, but you force yourself to say red. The speed with which you complete the task is supposedly an indicator of mental flexibility; older people generally take longer to say red. Likewise, inhibition control declines over time. If you're at a party and your nemesis walks through the door, you might be inclined to sock him in the nose. Instead, you shake his hand. Older people aren't likely to feel any different—they're just less likely to suppress their first instinct.
All of these behavioral changes have their basis in anatomy. As the brain ages, it starts to look different. It loses about 2 percent of its weight and volume every decade, starting around age 20. Certain areas of the cortex get smaller and thinner, and its grooves and ridges become more pronounced. The spaces between the gyri—the wormy coils you might call brains—often get wider as well.
The brain's chemistry also changes with age. Levels of dopamine, a neurotransmitter associated with sensations of happiness, generally decline. (Some schizophrenics, who experience abnormally high dopamine levels, recover suddenly when they reach a certain age.) Same with hormones like testosterone; on average, men in their 80s have testosterone levels 40 percent lower than men in their 20s. (Forget McCain, just ask Bob Dole.) The behavioral effects of lowered testosterone aren't known, but it's correlated with weaker cognition. But as recent history has shown, a president with low testosterone isn't necessarily a bad thing.
Roberto Cabeza of Duke University has conducted studies showing older adults often perform just as well as their younger counterparts because of what he calls "compensation." If one area of the brain is weaker, the theory goes, other areas will pick up the slack. For example, while younger people use the right side of their prefrontal cortex for high-level cognitive processing, some elderly people use the left side as well, resulting in equal performance. John McCain is old and, as several news outlets have reported, he's only getting older. This wouldn't be a problem if his opponent in ... more
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