Speed of Thought-to-Speech Traced in Brain

This is a brain scan showing electrodes that surgeons use to find and remove the source of seizures (to cure epilepsy) while sparing the source of mental functions like language. Credit: Illustration: Ned T. Sahin, Ph.D.. Brain Image Reconstruction: Sean McInerney.

From Live Science:

In just 600 milliseconds, the human brain can think of a word, apply the rules of grammar to it and send it to the mouth to be spoken. For the first time, researchers have traced this lightning-fast sequence and broken it down into distinct steps.

Researchers got this rare glimpse into the fine-tuned workings of the brain from the signals sent by electrodes implanted in the brains of epileptics. The electrodes help surgeons locate the parts of the brain that cause epileptic seizures so they can be removed, and also help keep surgeons from removing critical parts of the brain

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Expanding Waistlines May Cause Shrinking Brains

From New Scientist:

BRAIN regions key to cognition are smaller in older people who are obese compared with their leaner peers, making their brains look up to 16 years older than their true age. As brain shrinkage is linked to dementia, this adds weight to the suspicion that piling on the pounds may up a person's risk of the brain condition.
The brains of elderly obese people looked 16 years older than the brains of those who were lean

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My Comment: Does this mean that "skinny" people are smarter?

Evolution Of The Human Appendix: A Biological 'Remnant' No More

Normal location of the appendix relative to other organs of the digestive system (frontal view). (Credit: Wikimedia Commons)

From Science Daily:

Science Daily (Aug. 21, 2009) — The lowly appendix, long-regarded as a useless evolutionary artifact, won newfound respect two years ago when researchers at Duke University Medical Center proposed that it actually serves a critical function. The appendix, they said, is a safe haven where good bacteria could hang out until they were needed to repopulate the gut after a nasty case of diarrhea, for example.

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Our Eyes Constantly Flicker To Stop Us Going Blind, Experts Discover

Scientists believe flickering eye movements 'refresh' images on the retina

From The Daily Mail:

Unconscious flickering eye movements once thought to be random 'motor noise' may in fact be necessary to stop us going blind, a study has shown.

The imperceptible jumps and jiggles known as 'microsaccades' mean that a really steady stare is impossible.

Even when trying to fix a gaze on a stationary target, the eyes are always moving.

Experts have long dismissed these movements as the accidental result of spurious nerve signals. But new research shows they are actively controlled by the same brain region used to scan newspaper columns or track a moving object.

Scientists now think microsaccades provide a vital function by 'refreshing' images on the retina which would otherwise fade away.

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Reading This Will Change Your Brain

Jeff Sherman / Taxi-Getty Images

From Newsweek:

A leading neuroscientist says processing digital information can rewire your circuits. But is it evolution?

Is technology changing our brains? A new study by UCLA neuroscientist Gary Small adds to a growing body of research that says it is. And according to Small's new book, "iBRAIN: Surviving the Technological Alteration of the Modern Mind," a dramatic shift in how we gather information and communicate with one another has touched off an era of rapid evolution that may ultimately change the human brain as we know it. "Perhaps not since early man first discovered how to use a tool has the human brain been affected so quickly and so dramatically," he writes. "As the brain evolves and shifts its focus towards new technological skills, it drifts away from fundamental social skills."

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Your Brain Sees $$$ More Clearly Than You Know

Photo: Visual areas of the brain that responded more to valuable objects in a study that shows our brain may recognize value better than our conscious mind. Credit: John Serences, UC San Diego

From Live Science:

When you see something of value, your brain essentially sees dollar signs, a new study finds.

The effect occurs even if you don't consciously realize the object's worth.

Researchers scanned the brains of subjects who were presented with choices of constantly changing red and green objects that represented 10 cents or nothing, with good choices in a game leading to potential winnings of $10.

Upon seeing objects that had been of value previously, brain activity lit up in several areas, including a part of the cortex known as V1, which is associated with representing basic features such as edge orientations and color.

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Regenerate Your Brain? -The Science Says It's Possible

From Daily Galaxy:

Contrary to popular belief, recent studies have found that there are probably ways to regenerate brain matter.

Animal studies conducted at the National Institute on Aging Gerontology Research Center and the Johns Hopkins University School of Medicine, for example, have shown that both calorie restriction and intermittent fasting along with vitamin and mineral intake, increase resistance to disease, extend lifespan, and stimulate production of neurons from stem cells.

In addition, fasting has been shown to enhance synaptic elasticity, possibly increasing the ability for successful re-wiring following brain injury. These benefits appear to result from a cellular stress response, similar in concept to the greater muscular regeneration that results from the stress of regular exercise.

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Peripheral Artery Disease: Pain When Walking Can Be Reduced With Moderate Exercise, Study Suggests

From Science Daily:

ScienceDaily (Dec. 25, 2008) — You probably know that poor diet and lack of exercise can lead to dangerous deposits of fatty plaques in arteries. But it is not just the heart that is affected – blood flow can be blocked to the legs too, leading to pain when walking, immobility and even in extreme cases, amputation.

Approximately 20% of us will suffer from this peripheral artery disease (PAD) once we are 65 or over, and with risk factors including smoking, diabetes, obesity and high blood pressure it is on the rise. Surgical intervention can sometimes help, but the prognosis is not good.

Encouragingly, new research by Ronald Terjung et al. published in The Journal of Physiology shows that regular, moderate exercise can go a long way to relieving the symptoms of PAD, and by some unexpected mechanisms.

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Pavlov's Neurons: Brain Cells That Are A Key To Learning Discovered

Researchers have found individual neurons in the amygdalas of rat brains that are activated when the animals are given an associative learning task. (Credit: iStockphoto/Kiyoshi Takahase Segundo)

From Science Daily:

ScienceDaily (Dec. 9, 2008) — More than a century after Ivan Pavlov's dog was conditioned to salivate when it heard the sound of a tone prior to receiving food, scientists have found neurons that are critical to how people and animals learn from experience.

Using a new imaging technique called Arc catFISH, researchers from the University of Washington have visualized individual neurons in the amygdalas of rat brains that are activated when the animals are given an associative learning task.

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Forgotten But Not Gone: How The Brain Re-learns

Store room for future learning: nerve cells retain many of their newly created connections and if necessary, inactivate only transmission of the information. This makes relearning easier. (Credit: Image: Max Planck Institute of Neurobiology / Hofer)

From Science Daily:

ScienceDaily (Nov. 22, 2008) — Thanks to our ability to learn and to remember, we can perform tasks that other living things can not even dream of. However, we are only just beginning to get the gist of what really goes on in the brain when it learns or forgets something. What we do know is that changes in the contacts between nerve cells play an important role. But can these structural changes account for that well-known phenomenon that it is much easier to re-learn something that was forgotten than to learn something completely new?

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Blame The Human Brain For Bad Calls In Tennis

A ball landing on the baseline is captured by the "CBS Mac-Cam" named in honor of John McEnroe, who complained about official calls. Photo from CBS

From The L.A. Times:

Researchers studying Wimbledon games find humans are hard-wired to misjudge balls when hit close to the line.

UC Davis scientists have confirmed what tennis great John McEnroe so colorfully alleged on the court: Wimbledon referees make bad calls when judging balls hit close to the line.

It's not a matter of incompetence, as McEnroe frequently asserted. Rather, the human brain is hard-wired to misread the true position of fast-moving objects, including tennis balls whizzing by at more than 100 mph.

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Brain Starts To Slow Down At 40

From The Telegraph:

Life does not begin at 40 - it just slows down.

According to the latest research, our brain is fastest at 39 and afterwards, it declines "at an accelerating rate." That means that reactions also slow, claim the researchers.

The loss of a fatty skin that coats the nerve cells, called neurons, during middle age causes the slowdown, experts say.

The coating acts as insulation, similar to the plastic covering on an electrical cable, and allows for fast bursts of signals around the body and brain.

When the sheath deteriorates, signals passing along the neurons in the brain slow down. This means reaction times in the body are slower too.

Scientists at the University of California, Los Angeles, say that after 40 the body "loses the battle" to repair the protective sheaths.

The finding was made after researchers tested how quickly men aged from 23 to 80 could tap their index fingers in ten seconds.

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Men's Reactions Peak At Age 39

From Live Science:

This explains everything.

Scientists asked 72 men, ranging in age from 23 to 80, to tap their index fingers as fast as they could for 10 seconds. The researchers also did brain scans to measure in each subject the amount of myelin — a fatty sheath of insulation that coats nerve axons and allows for signaling bursts in our brains.

Both the tapping speed and the amount of myelin was found to decline "with an accelerating trajectory" after age 39.

Study leader George Bartzokis, professor of psychiatry at UCLA, called the results "pretty striking" and said: "That may well be why, besides achy joints and arthritis, even the fittest athletes retire and all older people move slower than they did when they were younger."

The myelination of brain circuits was known to peak in middle age. Bartzokis and others have long argued that brain aging might be primarily related to the myelin breakdown.

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'Hub' Of Fear Memory Formation Identified In Brain Cells

From Science Blog:

A protein required for the earliest steps in embryonic development also plays a key role in solidifying fear memories in the brains of adult animals, scientists have revealed. An apparent "hub" for changes in the connections between brain cells, beta-catenin could be a potential target for drugs to enhance or interfere with memory formation.

The results are published online this week and appear in the October issue of Nature Neuroscience.

The protein beta-catenin acts like a Velcro strap, fastening cells' internal skeletons to proteins on their external membranes that connect them with other cells. In species ranging from flies to frogs to mice, it also can transmit early signals that separate an embryo into front and back or top and bottom.

During long-term memory formation, structural changes take place in the synapses – the connections between neurons in the brain, says Kerry Ressler, MD, PhD, associate professor of psychiatry and behavioral sciences at Emory University School of Medicine. Ressler is a researcher at Emory University's Yerkes National Primate Research Center, where the research was conducted, and a Howard Hughes Medical Institute investigator.

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Scientists: Is Sleep Essential?

From Med Gadget:

Writing in the latest PLoS Biology, researchers from the University of Wisconsin, Madison are wondering whether sleep is really a biological necessity, or maybe it's just a function created by evolution to kill time and avoid stress.

From the article in PLoS Biology:

Everybody knows that sleep is important, yet the function of sleep seems like the mythological phoenix: “Che vi sia ciascun lo dice, dove sia nessun lo sa” (“that there is one they all say, where it may be no one knows,” Wolfgang Amadeus Mozart and Lorenzo da Ponte [1790], Così fan tutte). But what if the search for an essential function of sleep is misguided? What if sleep is not required but rather a kind of extreme indolence that animals indulge in when they have no more pressing needs, such as eating or reproducing? In many circumstances sleeping may be a less dangerous choice than roaming around, wasting energy and exposing oneself to predators. Also, if sleep is just one out of a repertoire of available behaviors that is useful without being essential, it is easier to explain why sleep duration varies so much across species. This “null hypothesis” would explain why nobody has yet identified a core function of sleep. But how strong is the evidence supporting it? And are there counterexamples?

So far the null hypothesis has survived better than alternatives positing some core function for sleep [8–10]. In what follows we shall test the null hypothesis by considering three of its key corollaries. If the null hypothesis were right, we would expect to find: (1) animals that do not sleep at all; (2) animals that do not need recovery sleep when they stay awake longer; and, finally, (3) that lack of sleep occurs without serious consequences.

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Understanding Memory

For The Brain, Remembering Is Like Reliving -- New York Times

Scientists have for the first time recorded individual brain cells in the act of summoning a spontaneous memory, revealing not only where a remembered experience is registered but also, in part, how the brain is able to recreate it.

The recordings, taken from the brains of epilepsy patients being prepared for surgery, demonstrate that these spontaneous memories reside in some of the same neurons that fired most furiously when the recalled event had been experienced. Researchers had long theorized as much but until now had only indirect evidence.

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