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Wednesday, February 1, 2012

The future of health care




The future of health careA DNA microarray displays gene sequences. ASU researcher Stuart Lindsay is developing a method for sequencing the human genome at a small fraction of the current cost. Credit: ASU Biodesign Insitute
The United States spends more per capita on health care than any other developed nation, and has the highest growth rate in health care costs, as well. In 2009, these costs reached $2.5 trillion, making up almost 1 in every 5 dollars – or 17 percent – of our gross domestic product.
In spite of these expenditures, the U.S. is far from the top of the list in terms of health care quality, efficiency or access. The World Health Organization ranked the U.S. only 37 out of 191 countries for overall health, responsiveness of the health system, and fairness in financing. Life expectancy in the U.S. ranks only 50th in the world, according to the CIA World Factbook.
To address these issues, a group of researchers at ASU are approaching health care from multiple, innovative perspectives. Their goals are to improve human health and well-being while simultaneously reducing the costs of care.
Creating high-value health care
One important reason that health care costs have skyrocketed while quality has not is that our current system is not designed to promote high-value health care, says Denis Cortese, the director of ASU's Health Care Delivery and Policy Program.
“There are a bunch of stakeholders that come to the table to maximize their own sector. It’s like an orchestra. If every player decided they were going to play as loud as they could, they’re not going to make very nice music,” Cortese says.
One factor driving up costs is that not everyone is insured. The law mandates that emergency rooms must treat anyone in need, regardless of whether or not they are insured. While this is good and necessary, Cortese says it encourages the uninsured to wait until they are very sick, and then go to the most expensive place for treatment. With 50 million uninsured Americans, those costs add up quickly.
The way in which health care providers are paid also increases costs, Cortese says.
“We pay money in a fee-for-service environment, which means I make more money if I keep you sick” Cortese says. “We pay doctors and hospitals and nurses more money the sicker you are – just the reverse of what we say we want. We’re not paying people to keep you healthy, we pay them when you’re sick.”
In order to receive payment from the federal health insurance program Medicare, which covers 47 million Americans, health care practitioners must keep extensive documentation of everything they do in treating a patient. This is where the “fee-for-service” concept comes in.
“The sicker you are, the more procedures you’re going to have done, the longer you’re in the hospital, the more money everybody makes. But the patient is getting sicker and we’re not getting the results we want,” Cortese says.
Doctors should be rewarded for keeping people healthy, rather than getting paid based on the tests and procedures they have done to treat a patient, he says.
At the Health Care Delivery and Policy Program, Cortese is working with 16 different organizations that want to provide high-value care for their patients, rather than participate in the fee-for-service model. The program connects these organizations with insurance providers who are willing to pay doctors and hospitals that want to provide better care for their patients.
Some of these health care providers are small, such as a single hospital, while others are large, spreading across multiple states and many different hospitals. All of the organizations want to provide better care at a lower cost to their patients.
“We need that mindset in health care that you’re not going to get paid until you’re producing high-value care,” Cortese says.
Technology to the rescue
One of the challenges in providing better care is that many hospitals and doctors’ offices have been slow to adopt technology that could simplify health care for everyone.
It’s common these days to get current traffic alerts on a smartphone, or to read about breaking news as it happens on Facebook or Twitter. With the capabilities to access instant, real-time information from almost anywhere, it’s surprising that many medical doctors are using outdated information technologies.
“It’s a frequent and bitter joke in the health care field that your average truck driver has better information technologies available to him than a doctor does in the office,” says Michael Birt, director of the Center for Sustainable Health in ASU’s Biodesign Institute.
Birt says that doctors often don’t have a good idea of how their patients are doing over time because no one continuously acquires and records that data.
“You go to a doctor every three months or six months, she tells you what to do, and then you ignore it until you go back again. That’s essentially how our health system works for prevention or primary care,” Birt says.
The center is working to implement technology that monitors a patient’s health over time and feeds that data back to their doctor. This will allow for a more meaningful health assessment than could be achieved in a single visit. That real-time data would also lead to faster diagnoses, and it will help patients recognize behaviors that are negatively impacting their health.
“It will be harder to pretend that something isn’t happening if that data is available,” Birt says.
In addition to improving individual health, a focus on technology and metrics could make health care more affordable and economically sustainable for the country. Birt says having access to current health data would allow doctors to determine a patient’s “biosignature,” or the most effective strategy to tackle that patient’s health issues.
A biosignature is a spectrum of health information that allows a system to know which diagnostic capabilities to use in a way that is cost-effective.
“The problem has been that technologies are often in silos, and our ability to integrate them has been very limited,” Birt says. For example, an X-ray will provide a completely different set of information than a blood test. They both meet a need, but one may be more appropriate than the other in a given situation.
“It’s not just doing the maximum number of tests. It’s doing the right one, at the right time, the right way, and with a cost impact,” Birt says.
Getting personal
Another way to lower costs, as well as reduce suffering, is to detect diseases early – possibly even before symptoms arise. For some diseases, like cancer, early detection can drastically improve the odds of survival.
Joshua LaBaer is the director of ASU’s Center for Personalized Diagnostics at the Biodesign Institute. One of the ongoing projects in his lab is identifying breast cancer biomarkers, which are unique molecular indicators of disease. These biomarkers will allow doctors to detect breast cancer earlier so that treatment can be administered earlier.
Using a new, powerful method for rapidly screening molecules associated with disease LaBaer’s team has identified a broad panel of 28 biomarkers that could aid in early diagnosis. They have also pinpointed more than 30 breast cancer gene targets – including several novel genes – that are involved in drug resistance to a leading chemotherapy treatment.
These gene targets exemplify a common problem in medical diagnosis and treatment. A single disease can affect people in different ways, because of their unique molecular composition.
“If you’ve got brothers and sisters, you’re probably astounded at how different they all are from you,” says Stuart Lindsay, the director of the Center for Single Molecule Biophysics at ASU’s Biodesign Institute. “Though your siblings carry basically very similar genomes, the way in which those genomes are ordered is radically different from child to child. This is the result of a process called meiotic recombination, which sort of throws the Darwinian dice every time a new human is conceived.”
The genome is the sum of a person’s hereditary information, encoded into his or her DNA. Genetic variation can cause two people diagnosed with the same type of cancer to respond differently to the same therapy. For example, the people with the genes identified by LaBaer’s group won’t derive much benefit from tamoxifen as a treatment for breast cancer, even though the drug is a lifesaver for many.
Knowing the genetic makeup of their patients could allow doctors to provide the best possible care for each patient. What’s the catch? Sequencing an entire human genome can cost tens to hundreds of thousands of dollars.
Lindsay developed a new method of sequencing and reading genomes that is faster and less expensive than other techniques currently available, because it doesn’t rely on chemical reactions. Instead, he uses the electronic properties of DNA to read the genome. He hopes that in five to 10 years, his technology will bring the cost of sequencing down into the double digits.
“The actual reading mechanism is done by passing the DNA through a nanopore,” Lindsay says. A nanopore is a tiny hole, about the size of a single DNA molecule, drilled into in a special silicon diffuser chip. Embedded in the nanopore is a tiny pair of electrodes. As each piece of the genome passes through the nanopore, researchers observe and record its reaction with the electrodes.
“It sounds like magic, but it actually works very well,” Lindsay says.
The ability to easily sequence a person’s genome will allow scientists to develop more personalized and precise therapies for diseases like cancer. Although the process is still expensive, it would ultimately save a lot of money.
“Right now there are cancer therapeutics on the market that cost tens of thousands of dollars per month and, on average, extend a person’s life by a few months. Hidden underneath that average statistic is the fact that one person in a large number goes into complete remission,” Lindsay says.
Investing in precision
If drug companies could profile the genomes of people who respond well to a particular treatment, they could customize treatments to the individual for maximum effect.
However, it’s not yet certain who will invest in the development of these treatments, LaBaer says, as pharmaceutical companies are not particularly interested in developing drugs that only work for a small number of people.
“If you were a pharmaceutical company, which would you rather do – develop a drug like Lipitor that you can give to millions of people who are at risk for heart disease, which is the most common killer in our country, or develop a drug for a small subset of women with a particular type of breast cancer?” LaBaer asks.
But there is an incentive for drug companies to invest in precision medicine, which brings us back to Stuart Lindsay’s genome sequencing. The ability to know on a molecular level which patients will respond well to a drug means that drug will have a high response rate. It also means doctors could identify people who won’t respond well to a drug and prevent negative side effects.
Some companies are already beginning to invest in precision. Lindsay’s lab has partnered with Roche, an international pharmaceutical company, and the technology and consulting corporation IBM. Roche will provide support for biochemical activities and IBM will construct the diffuser chips used to read the gene sequence.
“The hope of everyone in personalized medicine is that in some short number of years or decades at the most, this will be how medicine is practiced, and it will be lower-cost and make it much more effective,” Lindsay says.
Provided by Arizona State University
"The future of health care." January 31st, 2012. http://medicalxpress.com/news/2012-01-future-health.html
 

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Robert Karl Stonjek

Facebook is not such a good thing for those with low self-esteem




(Medical Xpress) -- In theory, the social networking website Facebook could be great for people with low self-esteem. Sharing is important for improving friendships. But in practice, people with low self-esteem seem to behave counterproductively, bombarding their friends with negative tidbits about their lives and making themselves less likeable, according to a new study which will be published in Psychological Science, a journal of the Association for Psychological Science.
“We had this idea that Facebook could be a really fantastic place for people to strengthen their relationships,” says Amanda Forest, a graduate student at the University of Waterloo. She cowrote the new study with her advisor, Joanne Wood. The two are generally interested in self-esteem, and how self-esteem affects the kinds of emotions people express. People with low self-esteem are often uncomfortable sharing face-to-face, but Facebook makes it possible to share remotely.
In one study, Forest and Wood asked students how they feel about Facebook. People with low self-esteem were more likely to think that Facebook provided an opportunity to connect with other people, and to perceive it as a safe place that reduces the risk of awkward social situations.
The researchers also investigated what students actually wrote on Facebook. They asked the students for their last 10 status updates, sentences like, “[Name] is lucky to have such terrific friends and is looking forward to a great day tomorrow!” and “[Name] is upset b/c her phone got stolen :@.” These are visible to their Facebook friends, the people in their network.
Each set of status updates was rated for how positive or negative it was. For each set of statements, a coder – an undergraduate Facebook user – rated how much they liked the person who wrote them.
People with low self-esteem were more negative than people with high self-esteem – and the coders liked them less. The coders were strangers, but that’s realistic, Forest says. In earlier research, Wood and Forest found that nearly half of Facebook friends are actually strangers or acquaintances, not close friends.
Forest and Wood also found that people with low self-esteem get more responses from their real Facebook friends when they post highly positive updates, compared to less positive ones. People with high self-esteem, on the other hand, get more responses when they post negative items, perhaps because these are rarer for them.
So people with low self-esteem may feel safe making personal disclosures on Facebook – but they may not be helping themselves. “If you’re talking to somebody in person and you say something, you might get some indication that they don’t like it, that they’re sick of hearing your negativity,” Forest says. But when people have a negative reaction to a post on Facebook, they seem to keep it to themselves. “On Facebook, you don’t see most of the reactions.”
Provided by American Psychiatric Association
"Facebook is not such a good thing for those with low self-esteem." January 31st, 2012. http://medicalxpress.com/news/2012-01-facebook-good-self-esteem.html
 

Comment:Find my Facebook Consciousness group Here
 

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Robert Karl Stonjek

Accidents don't just happen: New Book on trends and takeaways in injury research




Two esteemed researchers in the field of injury research have published the most comprehensive reference book to date on the methods and approaches underpinning the scientific discipline of injury control and prevention.
Editors Guohua Li, MD, DrPH, professor of epidemiology at Columbia University's Mailman School of Public Health and Susan Baker, MPH, ScD (Hon.), professor of Health Policy and Management at the Johns Hopkins Center for Injury Research and Policy, Johns Hopkins Bloomberg School of Public Health– both leaders in the field -- have brought together a team of global experts from public health, medicine, engineering, and behavioral and social sciences to write about the latest advances in theories and methods for understanding the causes, mechanisms, and outcomes of injury as well as the strategies to prevent injuries.
Called a milestone and a "bedrock text" for researchers by the publisher, Springer, this is an essential reference book for anyone interested in violence prevention, emergency medical services, trauma care, risk assessment, crash investigation and litigation, and vehicle, occupational, recreational, and home safety. The cadre of leaders assembled by Dr. Li, who is also professor of Anesthesiology at the Columbia College of Physicians and Surgeons, and Professor Baker deliver a state-of-the-art picture of where the field of injury research stands.
The 36 chapters are written by some of the most accomplished researchers in the world. The book allows the reader to appreciate how far the field of injury research has come since its beginning, as reflected by the following:
Injury is no longer considered a result of bad luck; it is not simply an "act of god".
Injury is predictable, preventable, and treatable, and even in a crash, fall, or shooting, there are effective interventions to lessen the risk, severity, and outcome of an injury.
Injury is now widely recognized as a health problem, and in the field of public health and medicine, the word accident is avoided by mentioning the crash, poisoning, fall, or other injury-producing event.
Injury is the subject of rigorous inquiries and interventions from multiple disciplines.
More information: The kindle version of the book is online as Injury Research: Theories, Methods, and Approaches.
Provided by Columbia University
"Accidents don't just happen: New Book on trends and takeaways in injury research." January 31st, 2012. http://medicalxpress.com/news/2012-01-accidents-dont-trends-takeaways-injury.html
 

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Robert Karl Stonjek

Body image not always a drag on women's wellbeing




Deakin University psychology researchers have found that body image isn't always a negative experience for women.
As part of her doctoral research, Rachel Chung from Deakin's School of Psychology is exploring women's experiences of their bodies and how this may be connected to how they feel about themselves in different aspects of their lives.
"The prevailing view on body image is that it is almost normal for women to be dissatisfied with their bodies," Ms Chung said.
"Most research on women's body image focuses on negative aspects, such as women's dissatisfaction with their shape and weight, and adverse factors associated with having a poor body image, such as poor self-esteem or an eating disorder.
"I'm interested in finding out how positive aspects of body image are related to women's sense of well-being."
Around 200 women aged 18 to 76 have already completed the survey for Ms Chung's project.
While past studies have highlighted the negative aspects associated with women's body image, Ms Chung's preliminary findings indicate that body image can also be a positive influence on women's lives.
"How women feel about themselves in general is associated with what they think about their bodies and their attitudes toward their physical health," Ms Chung explained.
"Women who were more accepting of themselves—that is they held positive attitudes towards themselves, accepted their good and bad qualities and past life events—reported that they deliberatively invested in a physically healthy lifestyle.
"The results revealed that for one third of women their body image had a positive impact on their emotional states, eating and exercise and sexual experiences. For one third of women, the impact was negative, and for one third there was no impact of body image on these variables.
"Women's attitudes about their body image were also related to their interpersonal relationships. Specifically, women who had more positive relations with others also reported that their body image had less impact on their lives."
Provided by Deakin University
"Body image not always a drag on women's wellbeing." January 31st, 2012. http://medicalxpress.com/news/2012-01-body-image-women-wellbeing.html
 

Posted by
Robert Karl Stonjek

Got creative block? Get out of your office and go for a walk




 
(Medical Xpress) -- The next time you're in need of creative inspiration, try thinking outside the box—or cubicle.
New research by Jeffrey Sanchez-Burks and Suntae Kim of the University of Michigan Ross School of Business shows that engaging in physical acts and experiences enhances creative problem-solving.
"Metaphors of creative thinking abound in everyday use," said Sanchez-Burks, associate professor of management and organizations. "By thinking 'outside the box,' by considering a problem 'on the one hand, then on the other hand' or by 'putting two and two together,' creativity presumably follows. Such prescriptive advice is no stranger within research labs, advertising teams, the halls of higher education or other contexts where pioneering novel approaches to pressing problems are valued. These metaphors suggest a connection between concrete bodily experiences and creative cognition."
Sanchez-Burks and Ross School doctoral student Kim assembled a team of international researchers who conducted five studies with nearly 400 college students to examine the psychological potency of creative metaphors by investigating whether creative problem-solving is enhanced when people literally follow these metaphors.
The studies ranged from requiring participants to generate ideas while first holding out their right hand and then their left hand ("on the one hand, then the other hand") to completing word tasks by either physically sitting inside or outside a box or engage in problem-solving by walking in a rectangular path vs. freely walking ("thinking outside the box") to converging multiple ideas to find solutions while combining two objects ("putting two and two together").
In all five studies, the findings revealed that physically and psychologically embodying creative metaphors promotes fluency, flexibility and originality in problem-solving, Sanchez-Burks said.
"The acts of alternately gesturing with each hand and of putting objects together may boost creative performance," he said. "Literally thinking outside or without physical constraints, such as walking outdoors or pacing around, may help eliminate unconscious mental barriers that restrict cognition.
"We shed new light by demonstrating that embodiment can potentially enlarge, not just activate, the repertoire of knowledge by triggering cognitive processes that are conducive for generating creative solutions. In other words, our body-mind linkages attest not only to processes of knowledge activation, but also knowledge generation. Embodying creative metaphors appears to help ignite the engine of creativity."
The research will appear in an upcoming issue of Psychological Science
 
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Provided by University of Michigan
"Got creative block? Get out of your office and go for a walk." January 31st, 2012. http://medicalxpress.com/news/2012-01-creative-block-office.html
 

Posted by
Robert Karl Stonjek

Short-term memory is based on synchronized brain oscillations




A monkey has to carry out a classic memory task: The animal is shown two consecutive images and then has to indicate whether the second image was the same as the first one. Credit: Stefanie Liebe, MPI for Biological Cybernetics
Scientists have now discovered how different brain regions cooperate during short-term memory.
Holding information within one's memory for a short while is a seemingly simple and everyday task. We use our short-term memory when remembering a new telephone number if there is nothing to write at hand, or to find the beautiful dress inside the store that we were just admiring in the shopping window. Yet, despite the apparent simplicity of these actions, short-term memory is a complex cognitive act that entails the participation of multiple brain regions. However, whether and how different brain regions cooperate during memory has remained elusive. A group of researchers from the Max Planck Institute for Biological Cybernetics in Tübingen, Germany have now come closer to answering this question. They discovered that oscillations between different brain regions are crucial in visually remembering things over a short period of time.
It has long been known that brain regions in the frontal part of the brain are involved in short-term memory, while processing of visual information occurs primarily at the back of the brain. However, to successfully remember visual information over a short period of time, these distant regions need to coordinate and integrate information.
In each of the two brain regions (IPF and V4) brain activity shows strong oscillations in a certain set of frequencies called the theta-band. Credit: Stefanie Liebe, MPI for Biological Cybernetics
To better understand how this occurs, scientists from the Max Planck Institute of Biological Cybernetics in the department of Nikos Logothetis recorded electrical activity both in a visual area and in the frontal part of the brain in monkeys. The scientists showed the animals identical or different images within short intervals while recording their brain activity. The animals then had to indicate whether the second image was the same as the first one.
The scientists observed that, in each of the two brain regions, brain activity showed strong oscillations in a certain set of frequencies called the theta-band. Importantly, these oscillations did not occur independently of each other, but synchronized their activity temporarily: "It is as if you have two revolving doors in each of the two areas. During working memory, they get in sync, thereby allowing information to pass through them much more efficiently than if they were out of sync," explains Stefanie Liebe, the first author of the study, conducted in the team of Gregor Rainer in cooperation with Gregor Hörzer from the Technical University Graz. The more synchronized the activity was, the better could the animals remember the initial image. Thus, the authors were able to establish a direct relationship between what they observed in the brain and the performance of the animal.
The study highlights how synchronized brain oscillations are important for the communication and interaction of different brain regions. Almost all multi-faceted cognitive acts, such as visual recognition, arise from a complex interplay of specialized and distributed neural networks. How relationships between such distributed sites are established and how they contribute to represent and communicate information about external and internal events in order to attain a coherent percept or memory is still poorly understood.
More information: Stefanie Liebe, Gregor M Hoerzer, Nikos K Logothetis & Gregor Rainer (2012) Theta coupling between V4 and prefrontal cortex predicts visual short-term memory performance. Nature Neuroscience, 29 January 2012, doi: 10.1038/nn.3038
 

Provided by Max-Planck-Gesellschaft
"Short-term memory is based on synchronized brain oscillations." January 31st, 2012. http://medicalxpress.com/news/2012-01-short-term-memory-based-synchronized-brain.html
 
Posted by
Robert Karl Stonjek

Gene mutation in autism found to cause hyperconnectivity in brain's hearing center




New research from Cold Spring Harbor Laboratory (CSHL) might help explain how a gene mutation found in some autistic individuals leads to difficulties in processing auditory cues and paying spatial attention to sound.
The study has found that when a suspected autism gene called PTEN is deleted from auditory cortical neurons—the main workhorses of the brain's sound-processing center—the signals that these neurons receive from local as well as long-distance sources are strengthened beyond normal levels. These effects, the study shows, can be blocked by a drug currently in use as an immunosuppressant.
"It's long been hypothesized that autism spectrum disorders (ASDs) arise from a partial disruption of long-range connections in the brain during development," explains Professor Tony Zador, who led the study. "Our finding that PTEN-deficient neurons receive stronger inputs suggests that one way this disruption can be caused is by signal enhancement." His team's work appears in the Journal of Neuroscience on February 1.
Although ASDs could arise from mutations in any of dozens of candidate genes, a core triad of symptoms defines all cases: impaired language, impaired social interaction, and restricted and repetitive behaviors. "The challenge therefore has been to understand how this diverse set of candidate genes and the pathways they control converge to cause the common signature of ASDs," Zador says.
The auditory cortex, which plays a critical role in auditory attention and perception, forms functional connections with other sensory cortices and critical brain areas. The neural network within the auditory cortex has therefore been a target of studies aimed at understanding how alterations in neural circuits contribute to dysfunction in ASDs.
Zador's team focused for several reasons on the role of one suspected autism candidate gene, PTEN, on circuit alterations within the auditory cortex. Well known for its role as an anti-cancer gene that powers down cell growth, proliferation and survival, this gene has also been linked to ASDs by a slew of studies in humans and mice. PTEN mutations have been found in autistic individuals with extreme macroencephaly – an increase in brain volume. PTEN loss in mice has been found to boost cell size and the number of neuronal connections in the brain.
To decipher the role of PTEN on functional connectivity in the auditory cortex, Zador's group selectively disrupted the function of the PTEN gene in adult mice, only in a subset of neurons of the auditory cortex, while leaving the gene intact in neighboring neurons. The scientists then assessed the effect of the loss of PTEN on connectivity within the auditory cortex using techniques that involve stimulation by laser or flashes of blue light to trigger neuronal activity either locally or in other brain areas that send neuronal projections into the auditory cortex.
The rapid and robust increase in the strength of both long-range and local inputs observed following PTEN loss could possibly be explained by an increase that the scientists observed in the length and density of dendritic spines – the tiny, knob-like structures jutting out of a neuron that act like signal-receiving antennae.
These effects could be blocked, however, by chemically negating the effect of PTEN loss. One of the pathways regulated by the PTEN protein involves shutting down an intracellular enzyme called mTORC1, which promotes cell growth, among other things. Zador's group found that treating the PTEN-deficient mice for 10 days with the mTORC1-inhibitor rapamycin prevented an increase in dendritic spine number and signal strength.
While Zador is excited about "this finding that suggests that mTORC1 could be a good therapeutic target for some cases of PTEN-mediated brain disorders," he is also keen to further pursue his team's new evidence that cortical hyperconnectivity could be the "final pathway" by which diverse ASD genetic pathways lead to a single ASD phenotype. "Using cortical connectivity as a paradigm for assessing ASD candidate genes could provide insights into the mechanisms of the disorders and perhaps even give us clues to formulate new therapeutic strategies," he states.
More information: "PTEN regulation of local and long-range connections in mouse auditory cortex" appears in the Journal of Neuroscience on February 1.
Provided by Cold Spring Harbor Laboratory
"Gene mutation in autism found to cause hyperconnectivity in brain's hearing center." January 31st, 2012. http://medicalxpress.com/news/2012-01-gene-mutation-autism-hyperconnectivity-brain.html
 

Posted by
Robert Karl Stonjek

Decoding brain waves to eavesdrop on what we hear



Neuroscientists may one day be able to hear the imagined speech of a patient unable to speak due to stroke or paralysis, according to University of California, Berkeley, researchers.
These scientists have succeeded in decoding electrical activity in the brain's temporal lobe – the seat of the auditory system – as a person listens to normal conversation. Based on this correlation between sound and brain activity, they then were able to predict the words the person had heard solely from the temporal lobe activity.
"This is huge for patients who have damage to their speech mechanisms because of a stroke or Lou Gehrig's disease and can't speak," said co-author Robert Knight, a UC Berkeley professor of psychology and neuroscience. "If you could eventually reconstruct imagined conversations from brain activity, thousands of people could benefit."
"This research is based on sounds a person actually hears, but to use it for reconstructing imagined conversations, these principles would have to apply to someone's internal verbalizations," cautioned first author Brian N. Pasley, a post-doctoral researcher in the center. "There is some evidence that hearing the sound and imagining the sound activate similar areas of the brain. If you can understand the relationship well enough between the brain recordings and sound, you could either synthesize the actual sound a person is thinking, or just write out the words with a type of interface device."
This video is not supported by your browser at this time.
These are frequency spectrograms of the actual spoken words (top) and the sounds as reconstructed by two separate models based solely on recorded temporal lobe activity in a volunteer subject. The words -- Waldo, structure, doubt and property -- are more or less recognizable, even though the model had never encountered these specific words before. Credit: Brian Pasley, UC Berkeley
In addition to the potential for expanding the communication ability of the severely disabled, he noted, the research also "is telling us a lot about how the brain in normal people represents and processes speech sounds."
Pasley and his colleagues at UC Berkeley, UC San Francisco, University of Maryland and The Johns Hopkins University report their findings Jan. 31 in the open-access journal PLoS Biology.
Help from epilepsy patients
They enlisted the help of people undergoing brain surgery to determine the location of intractable seizures so that the area can be removed in a second surgery. Neurosurgeons typically cut a hole in the skull and safely place electrodes on the brain surface or cortex – in this case, up to 256 electrodes covering the temporal lobe – to record activity over a period of a week to pinpoint the seizures. For this study, 15 neurosurgical patients volunteered to participate.
Pasley visited each person in the hospital to record the brain activity detected by the electrodes as they heard 5-10 minutes of conversation. Pasley used this data to reconstruct and play back the sounds the patients heard. He was able to do this because there is evidence that the brain breaks down sound into its component acoustic frequencies – for example, between a low of about 1 Hertz (cycles per second) to a high of about 8,000 Hertz –that are important for speech sounds.
Pasley tested two different computational models to match spoken sounds to the pattern of activity in the electrodes. The patients then heard a single word, and Pasley used the models to predict the word based on electrode recordings.
"We are looking at which cortical sites are increasing activity at particular acoustic frequencies, and from that, we map back to the sound," Pasley said. He compared the technique to a pianist who knows the sounds of the keys so well that she can look at the keys another pianist is playing in a sound-proof room and "hear" the music, much as Ludwig van Beethoven was able to "hear" his compositions despite being deaf.
The better of the two methods was able to reproduce a sound close enough to the original word for Pasley and his fellow researchers to correctly guess the word.
"We think we would be more accurate with an hour of listening and recording and then repeating the word many times," Pasley said. But because any realistic device would need to accurately identify words heard the first time, he decided to test the models using only a single trial.
"This research is a major step toward understanding what features of speech are represented in the human brain" Knight said. "Brian's analysis can reproduce the sound the patient heard, and you can actually recognize the word, although not at a perfect level."
Knight predicts that this success can be extended to imagined, internal verbalizations, because scientific studies have shown that when people are asked to imagine speaking a word, similar brain regions are activated as when the person actually utters the word.
"With neuroprosthetics, people have shown that it's possible to control movement with brain activity," Knight said. "But that work, while not easy, is relatively simple compared to reconstructing language. This experiment takes that earlier work to a whole new level."
Based on earlier work with ferrets
The current research builds on work by other researchers about how animals encode sounds in the brain's auditory cortex. In fact, some researchers, including the study's coauthors at the University of Maryland, have been able to guess the words ferrets were read by scientists based on recordings from the brain, even though the ferrets were unable to understand the words.
The ultimate goal of the UC Berkeley study was to explore how the human brain encodes speech and determine which aspects of speech are most important for understanding.
"At some point, the brain has to extract away all that auditory information and just map it onto a word, since we can understand speech and words regardless of how they sound," Pasley said. "The big question is, What is the most meaningful unit of speech? A syllable, a phone, a phoneme? We can test these hypotheses using the data we get from these recordings."
More information: Pasley BN, David SV, Mesgarani N, Flinker A, Shamma SA, et al. (2012) Reconstructing Speech from Human Auditory Cortex. PLoS Biol 10(1): e1001251. doi:10.1371/journal.pbio.1001251
Provided by University of California - Berkeley
"Decoding brain waves to eavesdrop on what we hear." January 31st, 2012. http://medicalxpress.com/news/2012-01-scientists-decode-brain-eavesdrop.html
 

Posted by
Robert Karl Stonjek

Scientists build working model of life's engine




USC scientists build working model of life's engineResearch associate Shayantani Mukherjee and USC Dornsife professor Arieh Warshel liken the rotation of F1-ATPase to that of a fan.
(PhysOrg.com) -- Researchers at the University of Southern California have built a theoretical working model of the cellular engine that powers all life.
The model will allow scientists to better understand the forces of life at the molecular level and potentially replicate them, including designing miniscule mechanical motors for nanomachines and nanorobots. The work was published online last month in Proceedings of the National Academy of Sciences.
“We were able to take a system that is very complicated and reproduce the crucial action in the system,” said Arieh Warshel, Distinguished Professor of Chemistry and Biochemistry in USC Dornsife. “We still have a lot of questions, but this is clearly a large step toward understanding the action of such ubiquitous engines in living systems.”
The body’s cellular engine is a protein molecule whose rotation generates the universal “fuel” — adenosine triphosphate (ATP) — that powers processes in living cells. The 1997 Nobel Prize in Chemistry was awarded to the scientists who elucidated the structure of this protein and outlined the principles of how it may operate.
The protein rotates, drawing in raw materials and synthesizing them into ATP. This fuel-generating engine can be divided into two parts, one of which is a rotating piece called F1-ATPase.
Warshel and research associate Shayantani Mukherjee built a computer-generated model of F1-ATPase that was remarkably successful at replicating the essential physical forces underlying the workings of the engine, mirroring the cellular motor’s unique unidirectional rotation.
Previous attempts to build such models relied on complex systems in which every atom was represented — making it difficult to determine why the motor is working, Warshel said.
Instead, Warshel and Mukherjee took a bare-bones approach, simplifying the structure — a strategy known in the computational biology world as “coarse-graining.”
“Make everything as simple as possible, but not simpler,” Warshel said.
Their simplified model rotated in the same manner as F1-ATPase, even pausing at exactly the same places. It also provided the clearest description yet of how the chemical energy of the ATP is used to rotate the motor and why the motor actually works.
Provided by University of Southern California
"Scientists build working model of life's engine." January 31st, 2012. http://www.physorg.com/news/2012-01-scientists-life.html
 

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