Saturday, October 29, 2011

Brain Waves Used to Steer Helicopter on Computer Screen, Offers Hope to the Disabled

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Imagine a person who is confined to a wheelchair but can still get around through nothing less than the power of thought.

Neuroscientists have experimented with brain waves for years, making slow progress. Now Dr. Bin He of the University of Minnesota and his team report a promising experiment.
They outfitted volunteers with caps with EEG sensors, and asked them to steer a helicopter on a computer screen through a series of randomly generated rings that appeared on the screen ahead of it. There were no hand controls, no joysticks. They could only try to will the helicopter forward with their minds.

It worked surprisingly well, Dr. He and his colleagues reported in the current issue of the online journal PLoS One. Eighty-five percent of the time, the volunteers could steer the virtual helicopter accurately.
"People have never done anything like this using noninvasive techniques," said He in a telephone interview. There have been other experiments before, but the most successful required that electrodes be surgically implanted in the brain. In one famous but sad case, Massachusetts researchers were able to get a young quadriplegic man to steer his own wheelchair -- but he ended the experiment, partly because he hated having wires inside his skull.


"Our technique was noninvasive," said He. The BCI -- short for brain-computer interface -- "is approaching the reliability that used to be done only by invasive procedures, though I will not say that it is better yet."
The challenge in using EEG signals is that they are, in the jargon of scientists, "noisy." The brain generates minute amounts of electricity as one thinks, and sensors can detect it, but readouts can look like random vibrations, and it is hard to tease out, say, a signal that means you want to turn left or right.
Earlier this year a team at the Berlin Institute of Technology in Germany reported they could detect drivers' intent to hit the brakes when they were at the control of a car simulator. But that was a relatively simple signal -- to brake or not -- and it came all of 130 milliseconds before the drivers actually tried to stop the car.
"While this may not seem [like] much, it may be enough to prevent accidents," said Stefan Haufe, the lead researcher, in an email to ABC News.

The Minnesota experiment was small -- three young female volunteers -- but the task was more ambitious. They set the EEG sensors to detect a particular brain wave called the sensorimotor rhythm.

"This was three-dimensional," he said . "The helicopter had to approach the ring, move forward, and go through without hitting it."

So it's one step at a time. But could it someday help a disabled person, without surgery, to use a robotic arm, or maneuver in the real world?

"We are always thinking of practical uses," said He. "That's the purpose of doing science."

Do not let stroke strike you down

Today is World Stroke Day
On the eve of World Stroke Day on October 29, doctors caution the public on the factors that cause stroke and how to watch for the warning signs and prevent disaster.

Neurologist at K.G. Hospital T.C.R. Ramakrishnan explains that stroke or cerebrovascular accident or brain attack occurs when the vessels supplying blood to the brain are blocked, interrupting the blood flow.

This results in the death of the brain cells. And, functions such as speech, memory or movement may be affected depending on the area of the brain involved.

Stroke is the second leading cause of death after the age of 60. Studies across the world show that cases of stroke occur every six seconds. It is not that stroke affects only elders. Stroke is the fifth leading cause of death in people aged 15 to 59 years. Stroke is indiscriminate and does not respect age, sex, race or economic status.
Stroke afflicts 15 million people each year. Of them, almost six million die and a further five million are left permanently disabled.
I
n 2009, the World Stroke Organisation fixed October 29 for the start of a global campaign titled “Stroke, what can I do?” The following year, it launched the “1 in 6” campaign to emphasise that one in six people will have a stroke within their life time.

This year, the organisation is continuing with the theme of 2010 “One in six”, but has added “Act Now” and “How to Act Now” as additional themes. It has listed some tasks (see graphics) that are critical to avoiding strokes.

Diabetologist V. Rajendran of Dr. Rajendran's Diabetes Centre says diabetes mellitus by itself is one of the major and independent risk factors for stroke. Large population studies have shown stroke to be more frequent and have higher mortality in patients with diabetes, with women being more prone to it.
The other associated risk factors increase this risk manifold. High blood pressure and cholesterol and high-risk habits such as use of tobacco and family history of stroke add to the risk that diabetes already poses.

Diabetics should constantly monitor blood sugar level and also other metabolic parameters such as cholesterol. Lifestyle and dietary changes should be made if any of these are found to breach normal limits.
 
Hypertension
State president of Indian Medical Association L.P. Thangavel says people are increasingly aware of stroke. Educated people also know that uncontrolled hypertension and diabetes are major risk factors.
But, much needs to be done in the rural areas to increase awareness. Hypertension and diabetes screening should be stepped up in rural areas and those found with the symptoms should be educated on the risks from the disease and how to avoid these.

Dr. Thangavel says the symptoms of stroke are easily understandable and primary level physicians can identify these. With imaging systems such as computed tomography available, detection is not a problem. Yet, physicians must approach the patients showing the symptoms (see graphics) with a high degree of suspicion so that accurate diagnosis is not missed.

Brain gene activity changes through life


Studies track biochemical patterns from just after conception to old age
 
Human brains all work pretty much the same and use roughly the same genes in the same way to build and maintain the infrastructure that makes people who they are, two new studies show. And by charting the brain’s genetic activity from before birth to old age, the studies reveal that the brain continually remodels itself in predictable ways throughout life.

In addition to uncovering details of how the brain grows and ages, the results may help scientists better understand what goes awry in brain disorders such as schizophrenia and autism.

“The complexity is mind-numbing,” says neuroscientist Stephen Ginsberg of the Nathan Kline Institute and New York University Langone Medical Center, who wasn’t involved in the studies. “It puts the brain in rarefied air.”

In the studies, published in the Oct. 27 Nature, researchers focused not on DNA — virtually every cell’s raw genetic material is identical — but on when, where and for how long each gene is turned on over the course of a person’s life. To do this, the researchers measured levels of mRNA, a molecule whose appearance marks one of the first steps in executing the orders contained in a gene, in postmortem samples of donated brains that ranged in age from weeks after conception to old age.

These different patterns of mRNA levels distinguish the brain from a heart, for instance, and a human from a mouse, too, says Nenad Šestan of Yale University School of Medicine and coauthor of one of the studies. “Essentially, we carry the same genes as mice,” he says. “However, in us, these genes are up to something quite different.”

To see what those genes were up to, Šestan’s study examined mRNA levels of different genes in 57 brain samples. The team divided the brain tissue up by region, so they were also able to get an idea of genes’ behavior in different parts of the brain. A parallel study, headed by Joel Kleinman of the National Institute of Mental Health in Bethesda, looked at gene behavior in 269 brain samples from a single region called the prefrontal cortex that also spanned the lifetime.
This approach allowed the researchers to get access to the brain that had previously been impossible.
“One of the limitations in studying human brain development is that you cannot do experiments,” Šestan says. “It’s very hard to understand when things happen.”

Both studies found lots of variation in gene behavior at different life stages, but one particular period stood out: The prenatal brain had massive changes in gene activity. Many genes there were pumping out big quantities of mRNA, and this production abruptly slowed after birth. “Prenatally, things are changing faster than they change at any other time,” says Carlo Colantuoni of the Lieber Institute for Brain Development at Johns Hopkins University Medical Center, and coauthor on one paper. “Things are happening fast in there.” 
Kleinman and his colleagues turned up a curious finding: Many of the genes that slow down right after birth show a surge of activity as a person gets older. “The biggest changes that are going on occur fetally,” he says. “And then they drop off until mid-life, and then in the 50s to 70s, expression changes pick up again and become quite dramatic.”

Researchers don’t yet know what to make of this reversal, says Colantuoni. “We have just scratched the surface of what it means.”

Genes involved with building new brain cells were highly active early on, and then this activity quickly fell after birth. As these genes grew less active, genes involved in linking up nerve cells took on a greater role and became busier.

What’s more, the differences in gene behavior between male and female brains were greatest at early stages of development. Some of the genes found to be busier in male brains have been linked to schizophrenia, autism and other disorders that are known to be more prevalent among males, the researchers report. These disease-associated genes are very active early on in development and less so as a person ages, the researchers found, suggesting that something goes wrong very early in these conditions.

The scientists don’t know exactly which cells are responsible for these gene behavior differences. Figuring out whether gene behavior changes in all kinds of cells in the brain — neurons and glia, for instance — is the next step, says Ginsberg. “That’s going to be really important, especially for neuropsychiatric disorders.”
Although gene behavior is incredibly dynamic, the results suggest that brains are more alike than different. Despite millions of differences in DNA, brains have a common biochemical shape, Kleinman says. Two people who have very different DNA make-up don’t necessarily have very different gene behavior in the brain. “These individual genetic variations, they do matter — no question,” he says. But overall, genes behave similarly from person to person. “And that’s a really cool thing. It means that we’re much more alike than we are different.”

Many more studies are needed before scientists fully understand how the brain is built. Both teams plan on boosting the number of brain samples and studying the brains of people with disorders such as schizophrenia and autism. But the work is a major step forward, says geneticist Christopher Mason of Weill Cornell Medical College of Cornell University in New York City. “This is extraordinary work,” he says. “This is the beginning of telling us what the whole brain looks like.
 

Watching horror movies good for brain

Horror movies are good for mental health
Scared of watching horror flicks? Well, its bad news for the ladies who are wary of watching such movies. 

Excuses for not watching the movies will not work anymore. Studies have shown that horror movies can be good for mental health and brain of women.

The benefit of watching scary movies proves that it has a positive effect on the mind, body and soul. Horror movies are not completely out of sync with reality. After all, it is the reality that creates fiction. So, watching such movies and relating with them is not a task at all. Thus, knowing it is fiction, a figment of imagination makes the audience sure that it is not real. Traumatic experiences after watching these horror and scary movies are rare because of this.

Research suggests that while women watch horror flicks, the brain secretes neurotransmitter dopamine, glutamate and serotonin. Thus, increased brain activity gets the state of mind alert for a while. Additionally , threat signals that pass through the hypothalamus (in the brain) will stimulate the adrenal glands to produce adrenaline and opiates which has an anesthesia like effect.
 
After watching the movie for half and hour, the system of the body will be calm and the defense system will become more powerful. That is when the immune system in the body will be stronger for a while.
 
So, no more excuses ladies. Watch horror flicks and be sure of having a positive effect on your mental health and body. Those who complain of heart complications should avoid watching such movies. Get ready, turn out the lights and watch some 'healthy' movies like Omen, The Exorcist and The exorcism of Emily Rose.

Brain Transcriptome Reveals Gender-Biased Gene Expression

Trajectories of genes identified which are linked to neurobiological categories and diseases

Generation and analysis of an exon-level transcriptome of the human brain and associated genotyping data shows that the transcriptome is organized into different coexpression networks, and shows gender-biased gene expression and exon usage, according to a study published in the Oct. 27 issue of Nature.

FRIDAY, Oct. 28 (HealthDay News) -- Generation and analysis of an exon-level transcriptome of the human brain and associated genotyping data shows that the transcriptome is organized into different coexpression networks, and shows gender-biased gene expression and exon usage, according to a study published in the Oct. 27 issue of Nature.

Hyo Jung Kang, Ph.D., from the Yale University School of Medicine in New Haven, Conn., and colleagues investigated the exon-level transcriptome and associated genotyping data, for males and females of different ethnicities, from multiple brain regions and neocortical areas of developing and adult postmortem human brains. A total of 1,340 tissue samples taken from 57 subjects, aged from 40 days after conception to 82 years, were analyzed.

The investigators found that 86 percent of the genes assessed were expressed. Of these, 90 percent were differentially regulated at the whole-transcript or exon level across brain regions and/or over time. Most of the regional and temporal differences were identified before birth; subsequent increases in the similarity were among regional transcriptomes. The brain transcriptome shows gender-biased gene expression and exon usage, and is organized into discrete coexpression networks. Trajectories of genes linked to neurobiological categories and diseases were found, and correlations were identified between single nucleotide polymorphisms and gene expression.

Dopamine release in human brain tracked at microsecond timescale reveals decision-making

A research team led by investigators at the Virginia Tech Carilion Research Institute has demonstrated the first rapid measurements of dopamine release in a human brain and provided preliminary evidence that the neurotransmitter can be tracked in its movement between brain cells while a subject expresses decision-making behavior.

"In an experiment where we measured dopamine release while a subject made investment decisions in a stock market trading game, we showed that dopamine tracks changes in the value of the market," said Read Montague, director of the Human Neuroimaging Laboratory at the Virginia Tech Carilion Research Institute and professor of physics in the College of Science at Virginia Tech.
"A startling discovery was that the dopamine signal appeared to be a very good indicator of the market value and in many instances a good predictor of future market changes," said Kenneth Kishida, a postdoctoral associate with the Human Neuroimaging Laboratory and the lead author on the report. Interestingly, the choice expressed by the subject did not always correspond with the prescient brain chemistry, he said.

The research was published on Aug. 4, 2011, in the Public Library of Science journal, PLoS ONE, in the article "Sub-Second Dopamine Detection in Human Striatum," by Kishida; Stefan G. Sandberg, senior fellow with the Departments of Psychiatry and Behavioral Sciences and Pharmacology, University of Washington, Seattle; Terry Lohrenz, assistant professor in the Department of Neuroscience, Baylor College of Medicine; Dr. Youssef G. Comair, professor and chief, Division of Neurosurgery, American University of Beirut, Lebanon; Ignacio Saez, assistant professor at Virginia Tech Carilion Research Institute; Paul E. M. Phillips, associate professor, Departments of Psychiatry and Behavioral Sciences and Pharmacology, University of Washington, Seattle; and Montague, senior author.

The researchers adapted their sensors to existing technology used for functional mapping of the brain during surgical implantation of deep-brain stimulation devices. "Deep-brain stimulation is typically used in the treatment of Parkinson's disease," said Montague. "Uses for treating other neurological disorders are also being investigated, though, and may open new avenues for the technology we developed."

The researchers applied criteria that employed experimental methodology that is "safe to the patient, compatible with existing neurosurgical apparatus and the operating-room environment, and capable of sub-second detection of physiological dopamine," they state in the article. They modified existing sensor technology to improve signal conductivity, creating a microsensor that shares the electrochemical properties of existing electrodes yet can detect sub-second dopamine release. "Even more important, the new microsensors are biocompatible and can be sterilized without affecting performance, " Kishida added.

The new instrument was demonstrated in a single human subject, a consenting patient with late-stage Parkinson's disease who was undergoing elective surgery for deep-brain stimulation electrode implantation.

The new microsensor was placed in the patient's brain and dopamine release was monitored as the patient engaged in a decision-making game. The current value and recent history of a stock market was graphically represented on a laptop monitor. The subject chose the proportion of a portfolio initially valued at $100 to be invested in the stock market. Decisions were submitted by pushing buttons on handheld response devices. Following the submission of each decision, the market was updated. The final portfolio determined the actual payout at the end of the experiment.

The researchers report that they were surprised to observe that "the slope of the dopamine signal over a period five seconds prior to a market price update correlated with subsequent market returns…, demonstrating that it is a significant predictor of future market activity."

To test this hypothesis, the researchers constructed a trader model that made decisions based on the fluctuations in the dopamine signal leading up to the market price changes. This decision model invested 100 percent, or all in, when the dopamine slope was positive and 0 percent, or all out, when the slope was negative. The researchers report that, "Over the five markets played, this trader model earned 202 points (a gain of 175 percent), more than two times the amount earned by the subject's expressed behavior. These data demonstrate that the information encoded in the dopamine signal of this patient is potentially useful for economic decision making."

"This exciting preliminary result requires replication, but it immediately sets the imagination in motion," said Kishida. "I often wonder whether there is a feeling associated with these dopamine fluctuations and whether there is any connection with that 'gut feeling' people sometimes ignore."

Writing in the PLoS ONE article, the researchers conclude, "This methodological demonstration opens the door to future investigations utilizing sub-second chemical measurements in the human brain, which should yield important insights into the role of dopamine signaling in human decision-making."

Genetic Regulation of Brain Development Implicated in Mental Illness


Complexity of Human Brain Increases Susceptibility to Mental Illness A major study of the genes associated with psychiatric illnesses has discovered that most of the genes are in place before birth in the developing human brain.
Yale University researchers also discovered that hundreds of genetic differences were found between males and females as their brains take shape in the womb.
The study is found in the journal Nature.
Neuroscientists estimate the human brain has a hundred billion brain cells requiring an incalculable number of connections.
In the study, Yale researchers tracked 86 percent of 17,000 human genes that are believed to be recruited in the effort to create the brain.
Investigators studied not only what genes are involved in development, but where and when they are expressed, or activated.
“We knew many of the genes involved in the development of the brain, but now we know where and when they are functioning in the human brain,” said Nenad Sestan, M.D., Ph.D., senior author of the study.
“The complexity of the system shows why the human brain may be so susceptible to psychiatric disorders.”
The study identified genes represented in the human brain, and when and where in the brain they were expressed. Scientists used more than 1,300 tissue samples taken from 57 subjects, aged from 40 days after conception to 82 years.
The analysis of over 1.9 billion data points by the Yale scientists created an unprecedented map of genetic activity in the brain at different stages of development.
Researchers were impressed to find much of the human brain is shaped prior to birth.
For instance, the team analyzed genes and variants previously linked with autism and schizophrenia, the symptoms of which are evident in the first few years of life or during early adulthood, respectively. The new analysis shows molecular evidence of expression of these suspect genes prior to birth.
“We found a distinct pattern of gene expression and variations prenatally in areas of the brain involving higher cognitive function,” Sestan said. “It is clear that these disease-associated genes are developmentally regulated.”
When comparing the brains of men and women, researchers noticed that in addition to the Y chromosome gene found in only in men, each gender presents distinct differences in many of genes that are shared by both sexes.
This difference was noted both for when the gene was expressed and the level of the gene’s activity. Most of the differences were noted prenatally.

Galloping ganglia: Random Dance studies the brain

FAR4_RaviDeepres.jpg
Alexander Whitley and Catarina Carvalho in "FAR"
According to British choreographer Wayne McGregor, when 18th-century scientists dissected the body and peered into its cavities, they had a hard time locating the soul. The more they learned about anatomy, the more elusive the body’s animating spirit became.
McGregor, whose company, Random Dance, returned to the Peak Performances series at Montclair State University, on Thursday, has a similar problem. He, too, is engaged in scientific research—cognitive studies that help latter-day investigators understand how the brain makes decisions. McGregor says that participating in these studies gives him and his dancers fresh ideas for how to proceed.
Yet something is missing from “Far,” the glamorous contemporary work making its local premiere. The ghost, in this case, is the choreographer himself—the agent who must tie the fractured movements and the segments of the show together. Though continuously surprising, the piece remains unsatisfying because McGregor does not allow us to glimpse the animating intelligence behind it. The choreographer is always our stand-in for God, but this one seems so concerned with creating new material that as it emerges, he forgets to shape it into a Divine Plan. He prefers flow to structure.
In every other respect, “Far” is stunning. McGregor’s dancers are sleek and shapely, moving with fluid assurance, and above the stage hangs a dazzling object: a rectangular LED display that continually changes appearance, generating new patterns of light and shadow by responding to stimuli. Shining promiscuously like a galaxy or retreating to a single glowing point, this machine is the evening’s star performer, and lighting designer Lucy Carter amplifies its effects with tinted clouds of smoke. Ben Frost’s episodic sound score ranges widely, from Vivaldi to the sound of animals grunting.
The piece opens with a striking image: Daniela Neugebauer standing center stage flanked by women torch-bearers, with Paolo Mangiola regarding her from a shadowy vantage off to the side. She seems inclined to ignore him, but after a quick pass to get a closer look, he insists upon engaging her in a duet that sets the tone for difficult relationships between men and women. Adjusting his grip, suddenly his hands are at her throat. Yet at another point, after shrugging him off she turns and offers her hand. Eventually they seem to reach a cool accord, lying parallel to each other.
A series of solos follows, with hinged movement that tends to emphasize a particular body part—first shoulders, and then ribs. Quick, struggling encounters characterize a group section, and later, in a bit of pantomime that stands out for its naturalness, Anna Nowak chats with Mangiola trying to put him off. He responds by seizing her wrists.
A male duet seems less coercive. Although it ends before both parties are quite ready, they salute each other with a courtly bow.
The final duet is the tenderest yet. Catarina Carvalho has the space to swivel in Alexander Whitley’s loose embrace, and she willingly hangs on his back with her hands pressed to his chest. Yet this freedom, too, seems like the prelude to a departure. She fades and lies still. He watches for a moment, and then turns to leave.