Some People Can Hallucinate Colors at Will

Some People Can Hallucinate Colors at Will

  9:57:00 AM    Science Lover

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Scientists at the University of Hull have found that some people have the ability to hallucinate colours at will -- even without the help of hypnosis.

Scientists at the University of Hull have found that some
people have the ability to hallucinate colours at will -- even
without the help of hypnosis. (Credit: © Paul Herbert / Fotolia)

The study, published this week in the journal Consciousness and Cognition, was carried out in the Department of Psychology at the University of Hull. It focused on a group of people that had shown themselves to be 'highly suggestible' in hypnosis.

The subjects were asked to look at a series of monochrome patterns and to see colour in them. They were tested under hypnosis and without hypnosis and both times reported that they were able to see colours.

Individuals' reactions to the patterns were also captured using an MRI scanner, which enabled the researchers to monitor differences in brain activity between the suggestible and non-suggestible subjects. The results of the research, showed significant changes in brain activity in areas of the brain responsible for visual perception among the suggestible subjects only.

Professor Giuliana Mazzoni, lead researcher on the project says: "These are very talented people. They can change their perception and experience of the world in ways that the rest of us cannot."

The ability to change experience at will can be very useful. Research has shown that hypnotic suggestions can be used to block pain and increase the effectiveness of psychotherapy.

It has always been assumed that hypnosis was needed for these effects to occur, but the new study suggests that this is not true. Although hypnosis does seem to heighten the subjects' ability to see colour, the suggestible subjects were also able to see colours and change their brain activity even without the help of hypnosis.

The MRI scans also showed clearly that although it was not necessary for the subjects to be under hypnosis to be able to perceive colours in the tests, it was evident that hypnosis increased the ability of the subjects to experience these effects.

Dr William McGeown, who also contributed to the study, says: "Many people are afraid of hypnosis, although it appears to be very effective in helping with certain medical interventions, particularly pain control. The work we have been doing shows that certain people may benefit from suggestion without the need for hypnosis."

The study, which was partially funded by the BBC, used a control group formed of less suggestible people, or people less likely to respond to hypnosis. It was found that this group of people were not able to hallucinate colour and, again, these reported results were supported by MRI scans.

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Scientists discover an organizing principle for our sense of smell

Scientists discover an organizing principle for our sense of smell

  12:13:00 AM    Science Lover

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The fact that certain smells cause us pleasure or disgust would seem to be a matter of personal taste. But new research at the Weizmann Institute shows that odors can be rated on a scale of pleasantness, and this turns out to be an organizing principle for the way we experience smell. The findings, which appeared today in Nature Neuroscience, reveal a correlation between the response of certain nerves to particular scents and the pleasantness of those scents. Based on this correlation, the researchers could tell by measuring the nerve responses whether a subject found a smell pleasant or unpleasant.

Our various sensory organs are have evolved patterns of organization that reflect the type of input they receive. Thus the receptors in the retina, in the back of the eye, are arranged spatially for efficiently mapping out visual coordinates. The structure of the inner ear, on the other hand, is set up according to a tonal scale. But the organizational principle for our sense of smell has remained a mystery: Scientists have not even been sure if there is a scale that determines the organization of our smell organ, much less how the arrangement of smell receptors on the membranes in our nasal passages might reflect such a scale.

A team headed by Prof. Noam Sobel of the Weizmann Institute's Neurobiology Department set out to search for the principle of organization for smell. Hints that the answer could be tied to pleasantness had been seen in research labs around the world, including that of Sobel, who had previously found a connection between the chemical structure of an odor molecule and its place on a pleasantness scale. Sobel and his team thought that smell receptors in the nose – of which there are some 400 subtypes – could be arranged on the nasal membrane according to this scale. This hypothesis goes against the conventional view, which claims that the various smell receptors are mixed -- distributed evenly, but randomly, around the membrane.



In the experiment, the researchers inserted electrodes into the nasal passages of volunteers and measured the nerves' responses to different smells in various sites. Each measurement actually captured the response of thousands of smell receptors, as these are densely packed on the membrane. The scientists found that the strength of the nerve signal varies from place to place on the membrane. It appeared that the receptors are not evenly distributed, but rather, that they are grouped into distinct sites, each engaging most strongly with a particular type of scent. Further investigation showed that the intensity of a reaction was linked to the odor's place on the pleasantness scale. A site where the nerves reacted strongly to a certain agreeable scent also showed strong reactions to other pleasing smells and vice versa: The nerves in an area with a high response to an unpleasant odor reacted similarly to other disagreeable smells. The implication is that a pleasantness scale is, indeed, an organizing principle for our smell organ.

But does our sense of smell really work according to this simple principle? Natural odors are composed of a large number of molecules – roses, for instance, release 172 different odor molecules. Nonetheless, says Sobel, the most dominant of those determine which sites on the membrane will react the most strongly, while the other substances make secondary contributions to the scent.

'We uncovered a clear correlation between the pattern of nerve reaction to various smells and the pleasantness of those smells. As in sight and hearing, the receptors for our sense of smell are spatially organized in a way that reflects the nature of the sensory experience,' says Sobel. In addition, the findings confirm the idea that our experience of smells as nice or nasty is hardwired into our physiology, and not purely the result of individual preference. Sobel doesn't discount the idea that individuals may experience smells differently. He theorizes that cultural context and personal experience may cause a certain amount of reorganization in smell perception over a person's lifetime.

More information: DOI: 10.1038/nn.2926

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World-Record Pulsed Magnetic Field Achieved; Lab Moves Closer to 100-Tesla Mark

World-Record Pulsed Magnetic Field Achieved; Lab Moves Closer to 100-Tesla Mark

  10:14:00 AM    Science Lover

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Researchers at the National High Magnetic Field Laboratory's Pulsed Field Facility at Los Alamos National Laboratory have set a new world record for the strongest magnetic field produced by a nondestructive magnet.

Yates Coulter, left, and Mike Gordon of Los Alamos National Laboratory make final preparations before successfully achieving a world-record for the strongest magnetic field produced by a nondestructive magnet. Working at the National High Magnetic Field Laboratory's Pulsed Field Facility at Los Alamos, a team of researchers achieved a field of 97.4 tesla, which is nearly 100 times stronger than the magnetic field found in giant electromagnets used in metal scrap yards. (Credit: Image courtesy of DOE/Los Alamos National Laboratory)

The scientists achieved a field of 92.5 tesla on Thursday, August 18, taking back a record that had been held by a team of German scientists and then, the following day, surpassed their achievement with a whopping 97.4-tesla field. For perspective, Earth's magnetic field is 0.0004 tesla, while a junk-yard magnet is 1 tesla and a medical MRI scan has a magnetic field of 3 tesla.

The ability to create pulses of extremely high magnetic fields nondestructively (high-power magnets routinely rip themselves to pieces due to the large forces involved) provides researchers with an unprecedented tool for studying fundamental properties of materials, from metals and superconductors to semiconductors and insulators. The interaction of high magnetic fields with electrons within these materials provides valuable clues for scientists about the properties of materials. With the recent record-breaking achievement, the Pulsed Field Facility at LANL, a national user facility, will routinely provide scientists with magnetic pulses of 95 tesla, enticing the worldwide user community to Los Alamos for a chance to use this one-of-a-kind capability.

The record puts the Los Alamos team within reach of delivering a magnet capable of achieving 100 tesla, a goal long sought by researchers from around the world, including scientists working at competing magnet labs in Germany, China, France, and Japan.

Such a powerful nondestructive magnet could have a profound impact on a wide range of scientific investigations, from how to design and control material functionality to research into the microscopic behavior of phase transitions. This type of magnet allows researchers to carefully tune material parameters while perfectly reproducing the non-invasive magnetic field. Such high magnetic fields confine electrons to nanometer scale orbits, thereby helping to reveal the fundamental quantum nature of a material.



Thursday's experiment was met with as much excitement as trepidation by the group of condensed matter scientists, high-field magnet technicians, technologists, and pulsed-magnet engineers who gathered to witness the NHMFL-PFF retake the world record. Crammed into the tight confines of the Magnet Lab's control room, they gathered, lab notebooks or caffeine of choice in hand. Their conversation reflected a giddy sense of anticipation tempered with nervousness.

With Mike Gordon commanding the controls that draw power off of a massive 1.4-gigawatt generator system and directs it to the magnet, all eyes and ears were keyed to video monitors showing the massive 100 tesla Multishot Magnet and the capacitor bank located in the now eerily empty Large Magnet Hall next door. The building had been emptied as a standard safety protocol.

Scientists heard a low warping hum, followed by a spine-tingling metallic screech signaling that the magnet was spiking with a precisely distributed electric current of more than 100 megajoules of energy. As the sound dissipated and the monitors confirmed that the magnet performed perfectly, attention turned to data acquired during the shot through two in-situ measurements -- proof positive that the magnet had achieved 92.5 tesla, thus yanking back from a team of German scientists a record that Los Alamos had previously held for five years.

The next day's even higher 97.4-tesla achievement was met with high-fives and congratulatory pats on the back. Later, researchers Charles Mielke, Neil Harrison, Susan Seestrom, and Albert Migliori certified with their signatures the data that would be sent to the Guiness Book of World Records.

The NHMFL is sponsored primarily by the National Science Foundation, Division of Materials Research, with additional support from the State of Florida and the DOE. These recent successes were enabled by long-term support from the U.S. Department of Energy's Office of Basic Energy Sciences, and the National Science Foundation's 100 Tesla Multi-Shot magnet program.

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Scientists Have New Help Finding Their Way Around Brain's Nooks and Crannies

Scientists Have New Help Finding Their Way Around Brain's Nooks and Crannies

  12:53:00 AM    Science Lover

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Like explorers mapping a new planet, scientists probing the brain need every type of landmark they can get. Each mountain, river or forest helps scientists find their way through the intricacies of the human brain.

Scientists have found a way to use MRI scanning data 
to map myelin, a white sheath that covers some brain 
cell branches. Such maps, previously only available via 
dissection, help scientists determine precisely where they 
are at in the brain. Red and yellow indicate regions with 
high myelin levels; blue, purple and black areas have low 
myelin levels. (Credit: David Van Essen)

Researchers at Washington University School of Medicine in St. Louis have developed a new technique that provides rapid access to brain landmarks formerly only available at autopsy. Better brain maps will result, speeding efforts to understand how the healthy brain works and potentially aiding in future diagnosis and treatment of brain disorders, the researchers report in the Journal of Neuroscience Aug. 10.

The technique makes it possible for scientists to map myelination, or the degree to which branches of brain cells are covered by a white sheath known as myelin in order to speed up long-distance signaling. It was developed in part through the Human Connectome Project, a $30 million, five-year effort to map the brain's wiring. That project is headed by Washington University in St. Louis and the University of Minnesota.

"The brain is among the most complex structures known, with approximately 90 billion neurons transmitting information across 150 trillion connections," says David Van Essen, PhD, Edison Professor and head of the Department of Anatomy and Neurobiology at Washington University. "New perspectives are very helpful for understanding this complexity, and myelin maps will give us important insights into where certain parts of the brain end and others begin."

Easy access to detailed maps of myelination in humans and animals also will aid efforts to understand how the brain evolved and how it works, according to Van Essen.

Neuroscientists have known for more than a century that myelination levels differ throughout the cerebral cortex, the gray outer layer of the brain where most higher mental functions take place. Until now, though, the only way they could map these differences in detail was to remove the brain after death, slice it and stain it for myelin.

Washington University graduate student Matthew Glasser developed the new technique, which combines data from two types of magnetic resonance imaging (MRI) scans that have been available for years.



"These are standard ways of imaging brain anatomy that scientists and clinicians have used for a long time," Glasser says. "After developing the new technique, we applied it in a detailed analysis of archived brain scans from healthy adults."

As in prior studies, Glasser's results show highest myelination levels in areas involved with early processing of information from the eyes and other sensory organs and control of movement. Many brain cells are packed into these regions, but the connections among the cells are less complex. Scientists suspect that these brain regions rely heavily on what computer scientists call parallel processing: Instead of every cell in the region working together on a single complex problem, multiple separate teams of cells work simultaneously on different parts of the problem.

Areas with less myelin include brain regions linked to speech, reasoning and use of tools. These regions have brain cells that are packed less densely, because individual cells are larger and have more complex connections with neighboring cells.

"It's been widely hypothesized that each chunk of the cerebral cortex is made up of very uniform information-processing machinery," Van Essen says. "But we're now adding to a picture of striking regional differences that are important for understanding how the brain works."

According to Van Essen, the technique will make it possible for the Connectome project to rapidly map myelination in many different research participants. Data on many subjects, acquired through many different analytical techniques including myelination mapping, will help the resulting maps cover the range of anatomic variation present in humans.

"Our colleagues are clamoring to make use of this approach because it's so helpful for figuring out where you are in the cortex, and the data are either already there or can be obtained in less than 10 minutes of MRI scanning," Glasser says.

This research was funded by the National Institutes of Health (NIH).

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Researchers can predict future actions from human brain activity

Researchers can predict future actions from human brain activity

  2:42:00 AM    Science Lover

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Bringing the real world into the brain scanner, researchers at The University of Western Ontario from The Centre for Brain and Mind can now determine the action a person was planning, mere moments before that action is actually executed.

A volunteer completes tasks while in the functional magnetic
imaging (fMRI) machine. This research project focuses
on understanding how the human brain plans actions.

The findings were published this week in the prestigious Journal of Neuroscience, in the paper, "Decoding Action Intentions from Preparatory Brain Activity in Human Parieto-Frontal Networks."



"This is a considerable step forward in our understanding of how the human brain plans actions," says Jason Gallivan, a Western Neuroscience PhD student, who was the first author on the paper.

University of Western Ontario researchers Jody Culham and Jason Gallivan describe how they can use a fMRI to determine the action a person was planning, mere moments before that action is actually executed. Credit: The University of Western Ontario

Over the course of the one-year study, human subjects had their brain activity scanned using functional magnetic resonance imaging (fMRI) while they performed one of three hand movements: grasping the top of an object, grasping the bottom of the object, or simply reaching out and touching the object. The team found that by using the signals from many brain regions, they could predict, better than chance, which of the actions the volunteer was merely intending to do, seconds later.

"Neuroimaging allows us to look at how action planning unfolds within human brain areas without having to insert electrodes directly into the human brain. This is obviously far less intrusive," explains Western Psychology professor Jody Culham, who was the paper's senior author.

Gallivan says the new findings could also have important clinical implications: "Being able to predict a human's desired movements using brain signals takes us one step closer to using those signals to control prosthetic limbs in movement-impaired patient populations, like those who suffer from spinal cord injuries or locked-in syndrome."

                    Brain timecourse video of subject's fMRI image during experiment

Provided by University of Western Ontario

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Using Magnets to Help Prevent Heart Attacks: Magnetic Field Can Reduce Blood Viscosity, Physicist Discovers

Using Magnets to Help Prevent Heart Attacks: Magnetic Field Can Reduce Blood Viscosity, Physicist Discovers

  10:47:00 AM    Science Lover

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If a person's blood becomes too thick it can damage blood vessels and increase the risk of heart attacks. But a Temple University physicist has discovered that he can thin the human blood by subjecting it to a magnetic field.

Aggregated red-cell clusters have a streamlined 
shape, leading to further viscosity reduction. 
(Credit: Image courtesy of Temple University)

Rongjia Tao, professor and chair of physics at Temple University, has pioneered the use of electric or magnetic fields to decrease the viscosity of oil in engines and pipelines. Now, he is using the same magnetic fields to thin human blood in the circulation system.

Because red blood cells contain iron, Tao has been able to reduce a person's blood viscosity by 20-30 percent by subjecting it to a magnetic field of 1.3 Telsa (about the same as an MRI) for about one minute.

Tao and his collaborator tested numerous blood samples in a Temple lab and found that the magnetic field polarizes the red blood cells causing them to link together in short chains, streamlining the movement of the blood. Because these chains are larger than the single blood cells, they flow down the center, reducing the friction against the walls of the blood vessels. The combined effects reduce the viscosity of the blood, helping it to flow more freely.

When the magnetic field was taken away, the blood's original viscosity state slowly returned, but over a period of several hours.

"By selecting a suitable magnetic field strength and pulse duration, we will be able to control the size of the aggregated red-cell chains, hence to control the blood's viscosity," said Tao. "This method of magneto-rheology provides an effective way to control the blood viscosity within a selected range."

Currently, the only method for thinning blood is through drugs such as aspirin; however, these drugs often produce unwanted side effects. Tao said that the magnetic field method is not only safer, it is repeatable. The magnetic fields may be reapplied and the viscosity reduced again. He also added that the viscosity reduction does not affect the red blood cells' normal function.



Tao said that further studies are needed and that he hopes to ultimately develop this technology into an acceptable therapy to prevent heart disease.

Tao and his former graduate student, Ke "Colin" Huang, now a medical physics resident in the Department of Radiation Oncology at the University of Michigan, are publishing their findings in the journal Physical Review E.

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Extra Prenatal Testosterone Makes a Genius?

Extra Prenatal Testosterone Makes a Genius?

  7:01:00 PM    Science Lover

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A longstanding debate as to whether genius is a byproduct of good genes or good environment has an upstart challenger that may take the discussion in an entirely new direction. University of Alberta researcher Marty Mrazik says being bright may be due to an excess level of a natural hormone.

A longstanding debate as to whether genius is a 
byproduct of good genes or good environment has an 
upstart challenger that may take the discussion in an 
entirely new direction. University of Alberta researcher 
Marty Mrazik says being bright may be due to an 
excess level of a natural hormone. 
(Credit: iStockphoto/Vasiliy Yakobchuk)

 

Mrazik, a professor in the Faculty of Education's educational psychology department, and a colleague from Rider University in the U.S., have published a paper in Roeper Review linking giftedness (having an IQ score of 130 or higher) to prenatal exposure of higher levels of testosterone. Mrazik hypothesizes that, in the same way that physical and cognitive deficiencies can be developed in utero, so, too, could similar exposure to this naturally occurring chemical result in giftedness.

"There seems to be some evidence that excessive prenatal exposure to testosterone facilitates increased connections in the brain, especially in the right prefrontal cortex," said Mrazik. "That's why we see some intellectually gifted people with distinct personality characteristics that you don't see in the normal population."

Mrazik's notion came from observations made during clinical assessments of gifted individuals. He and his fellow researcher observed some specific traits among the subjects. This finding stimulated a conversation on the role of early development in setting the foundation for giftedness.

"It gave us some interesting ideas that there could be more to this notion of genius being predetermined from a biological perspective than maybe people gave it credit for," said Mrazik. "It seemed that the bulk of evidence from new technologies (such as Functional MRI scans) tell us that there's a little bit more going on than a genetic versus environmental interaction."

Based on their observations, the researchers made the hypothesis that this hormonal "glitch" in the in-utero neurobiological development means that gifted children are born with an affinity for certain areas such as the arts, math or science. Mrazik cautions that more research is needed to determine what exact processes may cause the development of the gifted brain.

He notes that more is known about what derails the brain's normal development, thus charting what makes gifted people gifted is very much a new frontier. Mrazik hopes that devices such as the Functional MRI scanner will give them a deeper understanding of the role of neurobiology in the development of the gifted brain.

"It's really hard to say what does put the brain in a pathway where it's going to be much more precocious," he said. "The next steps in this research lay in finding out what exact stimuli causes this atypical brain development."

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Parts of Brain Can Switch Functions: In People Born Blind, Brain Regions That Usually Process Vision Can Tackle Language

Parts of Brain Can Switch Functions: In People Born Blind, Brain Regions That Usually Process Vision Can Tackle Language

  9:52:00 AM    Science Lover

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When your brain encounters sensory stimuli, such as the scent of your morning coffee or the sound of a honking car, that input gets shuttled to the appropriate brain region for analysis. The coffee aroma goes to the olfactory cortex, while sounds are processed in the auditory cortex.

MRI scan of brain. (Credit: iStockphoto)

 

That division of labor suggests that the brain's structure follows a predetermined, genetic blueprint. However, evidence is mounting that brain regions can take over functions they were not genetically destined to perform. In a landmark 1996 study of people blinded early in life, neuroscientists showed that the visual cortex could participate in a nonvisual function -- reading Braille.

Now, a study from MIT neuroscientists shows that in individuals born blind, parts of the visual cortex are recruited for language processing. The finding suggests that the visual cortex can dramatically change its function -- from visual processing to language -- and it also appears to overturn the idea that language processing can only occur in highly specialized brain regions that are genetically programmed for language tasks.

"Your brain is not a prepackaged kind of thing. It doesn't develop along a fixed trajectory, rather, it's a self-building toolkit. The building process is profoundly influenced by the experiences you have during your development," says Marina Bedny, an MIT postdoctoral associate in the Department of Brain and Cognitive Sciences and lead author of the study, which appears in the Proceedings of the National Academy of Sciences the week of Feb. 28.

Flexible connections

For more than a century, neuroscientists have known that two specialized brain regions -- called Broca's area and Wernicke's area -- are necessary to produce and understand language, respectively. Those areas are thought to have intrinsic properties, such as specific internal arrangement of cells and connectivity with other brain regions, which make them uniquely suited to process language.

Other functions -- including vision and hearing -- also have distinct processing centers in the sensory cortices. However, there appears to be some flexibility in assigning brain functions. Previous studies in animals (in the laboratory of Mriganka Sur, MIT professor of brain and cognitive sciences) have shown that sensory brain regions can process information from a different sense if input is rewired to them surgically early in life. For example, connecting the eyes to the auditory cortex can provoke that brain region to process images instead of sounds.

Until now, no such evidence existed for flexibility in language processing. Previous studies of congenitally blind people had shown some activity in the left visual cortex of blind subjects during some verbal tasks, such as reading Braille, but no one had shown that this might indicate full-fledged language processing.

Bedny and her colleagues, including senior author Rebecca Saxe, assistant professor of brain and cognitive sciences, and Alvaro Pascual-Leone, professor of neurology at Harvard Medical School, set out to investigate whether visual brain regions in blind people might be involved in more complex language tasks, such as processing sentence structure and analyzing word meanings.

To do that, the researchers scanned blind subjects (using functional magnetic resonance imaging) as they performed a sentence comprehension task. The researchers hypothesized that if the visual cortex was involved in language processing, those brain areas should show the same sensitivity to linguistic information as classic language areas such as Broca's and Wernicke's areas.

They found that was indeed the case -- visual brain regions were sensitive to sentence structure and word meanings in the same way as classic language regions, Bedny says. "The idea that these brain regions could go from vision to language is just crazy," she says. "It suggests that the intrinsic function of a brain area is constrained only loosely, and that experience can have really a big impact on the function of a piece of brain tissue."

Bedny notes that the research does not refute the idea that the human brain needs Broca's and Wernicke's areas for language. "We haven't shown that every possible part of language can be supported by this part of the brain [the visual cortex]. It just suggests that a part of the brain can participate in language processing without having evolved to do so," she says.

Redistribution

One unanswered question is why the visual cortex would be recruited for language processing, when the language processing areas of blind people already function normally. According to Bedny, it may be the result of a natural redistribution of tasks during brain development.

"As these brain functions are getting parceled out, the visual cortex isn't getting its typical function, which is to do vision. And so it enters this competitive game of who's going to do what. The whole developmental dynamic has changed," she says.

This study, combined with other studies of blind people, suggest that different parts of the visual cortex get divvied up for different functions during development, Bedny says. A subset of (left-brain) visual areas appears to be involved in language, including the left primary visual cortex.

It's possible that this redistribution gives blind people an advantage in language processing. The researchers are planning follow-up work in which they will study whether blind people perform better than sighted people in complex language tasks such as parsing complicated sentences or performing language tests while being distracted.

The researchers are also working to pinpoint more precisely the visual cortex's role in language processing, and they are studying blind children to figure out when during development the visual cortex starts processing language.
 

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Brain Matter Linked to Introspective Thoughts Structure of Prefrontal Cortex Helps Humans Think About One's Own Thinking

Brain Matter Linked to Introspective Thoughts Structure of Prefrontal Cortex Helps Humans Think About One's Own Thinking

  9:51:00 AM    Science Lover

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A specific region of the brain appears to be larger in individuals who are good at turning their thoughts inward and reflecting upon their decisions, according to new research published in the journal Science. This act of introspection -- or "thinking about your thinking" -- is a key aspect of human consciousness, though scientists have noted plenty of variation in peoples' abilities to introspect.

Views of inflated cortical surface showing areas of brain gray matter correlating with introspective accuracy. (Credit: Image © Science/AAAS)

The new study will be published in the 17 September issue of the journal Science. Science is published by AAAS, the nonprofit science society.

In light of their findings, this team of researchers, led by Prof. Geraint Rees from University College London, suggests that the volume of gray matter in the anterior prefrontal cortex of the brain, which lies right behind our eyes, is a strong indicator of a person's introspective ability. Furthermore, they say the structure of white matter connected to this area is also linked to this process of introspection.

It remains unclear, however, how this relationship between introspection and the two different types of brain matter really works. These findings do not necessarily mean that individuals with greater volume of gray matter in that region of the brain have experienced -- or will experience -- more introspective thoughts than other people. But, they do establish a correlation between the structure of gray and white matter in the prefrontal cortex and the various levels of introspection that individuals may experience.

In the future, the discovery may help scientists understand how certain brain injuries affect an individual's ability to reflect upon their own thoughts and actions. With such an understanding, it may eventually be possible to tailor appropriate treatments to patients, such as stroke victims or those with serious brain trauma, who may not even understand their own conditions.

"Take the example of two patients with mental illness -- one who is aware of their illness and one who is not," said one of the study's authors, Stephen Fleming from University College London. "The first person is likely to take their medication, but the second is less likely. If we understand self-awareness at the neurological level, then perhaps we can also adapt treatments and develop training strategies for these patients."

This new study was born from collaboration between Rees' group, which investigates consciousness, and another group at University College London led by Prof. Ray Dolan, which studies decision-making. Fleming, together with co-author Rimona Weil, designed an experiment to measure both an individual's performance at a task, as well as how confident that individual felt about his or her decisions during the task. By taking note of how accurately the study's participants were able to judge their own decision-making, the researchers were able to gain insight into the participants' introspective abilities.

To begin, Fleming and Weil recruited 32 healthy human participants and showed them two screens, each containing six patterned patches. One of the screens, however, contained a single patch that was brighter than all the rest. The researchers asked the participants to identify which screen contained the brighter patch, and then to rate how confident they felt about their final answer. After the experiment, participants' brains were scanned using magnetic resonance imaging, or MRI.

Fleming and the researchers designed the task to be difficult, so that participants were never completely sure if their answer was correct. They reasoned that participants who are good at introspection would be confident after making correct decisions about the patch, and less confident when they were incorrect about the patch. By adjusting the task, the researchers ensured all of the participants' decision-making abilities were on par with each others' -- only the participants' knowledge of their own decision-making abilities differed.

"It's like that show, 'Who Wants to Be a Millionaire?'" said Weil. "An introspective contestant will go with his or her final answer when they are quite sure of it, and perhaps phone a friend when they are unsure. But, a contestant who is less introspective would not be as effective at judging how likely their answer is to be correct."

So, although each participant performed equally well at the task, their introspective abilities did vary considerably, the researchers confirmed. By comparing the MRI scans of each participant's brain, they could then identify a correlation between introspective ability and the structure of a small area of the prefrontal cortex. An individual's meta-cognitive, or "higher-thinking," abilities were significantly correlated with the amount of gray matter in the right anterior prefrontal cortex and the structure of neighboring white matter, Rees and his team found.

These findings, however, could reflect the innate differences in our anatomy, or alternatively, the physical effects of experience and learning on the brain. The latter possibility raises the exciting prospect that there may be a way to "train" meta-cognitive abilities by exploiting the malleable nature of these regions of prefrontal cortex. But, more research is needed to explore the mental computations behind introspection -- and then to link these computations to actual biological processes.

"We want to know why we are aware of some mental processes while others proceed in the absence of consciousness," said Fleming. "There may be different levels of consciousness, ranging from simply having an experience, to reflecting upon that experience. Introspection is on the higher end of this spectrum -- by measuring this process and relating it to the brain we hope to gain insight into the biology of conscious thought."

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Mental Maturity Scan Tracks Brain Development

Mental Maturity Scan Tracks Brain Development

  9:26:00 PM    Science Lover

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Five minutes in a scanner can reveal how far a child's brain has come along the path from childhood to maturity and potentially shed light on a range of psychological and developmental disorders, scientists at Washington University School of Medicine in St. Louis have shown.

Researchers have shown that functional brain 
networks have the potential to help physicians 
probe psychiatric and developmental disorders. 
In this graphic, the brain regions that are important 
to assessing the maturity of the brain are shown as 
spheres, with the size of the sphere representing the 
region's relative importance. Different sphere colors 
identify brain regions as members of different
functional networks. The orange connections 
strengthen and the green connections weaken as the 
brain progresses toward adulthood. (Credit: 
Image courtesy of Washington University 
School of Medicine)

Researchers assert in Science that their study proves brain imaging data can offer more extensive help in tracking aberrant brain development.

"Pediatricians regularly plot where their patients are in terms of height, weight and other measures, and then match these up to standardized curves that track typical developmental pathways," says senior author Bradley Schlaggar, MD, PhD, a Washington University pediatric neurologist. "When the patient deviates too strongly from the standardized ranges or veers suddenly from one developmental path to another, the physician knows there's a need to start asking why."

Schlaggar and his colleagues say a new way of looking at brain scanning data may be able to provide similar guidance for monitoring and treating of patients with psychiatric and developmental disorders.

Schlaggar, the A. Ernest and Jane G. Stein Associate Professor of Neurology, says he has sent children with obvious, profound psychiatric conditions for MRI scans and received results marked "no abnormalities noted."

"That's typically looking at the data from a structural point of view -- what's different about the shapes of various brain regions," he says. "But MRI also offers ways to analyze how different parts of the brain work together functionally."

Compare functional data to standardized models of how brain function or disease normally develops, Schlaggar says, and a range of new clinical insights becomes available.

Schlaggar and his colleagues use an approach to brain scanning called resting state functional connectivity. By correlating increases and decreases in blood flow to the various brain regions as subjects rest in the scanner, scientists determine which of these regions work together in brain networks.

In a study published in 2009, Washington University scientists showed that as the brain matures, these brain networks change. The overall organization switches from networks involving regions physically close to each other, which is the dominant motif in a child's brain, to networks that connect distant regions, the primary organizational principal in adult brains.

For the new study, lead author Nico Dosenbach, MD, PhD, a pediatric neurology resident at St. Louis Children's Hospital, took this and other distinctions that mark the transition from child to adult brain and adapted them for use in a technique for mathematical analysis called a support vector machine. The technique is employed in many contexts in science and economics and on the Internet.

"It's a way that mathematicians have developed for predicting something with high specificity and sensitivity when you have huge amounts of data instead of one really good measurement," Dosenbach explains. "Any one of these measurements doesn't tell you much, but if you put them together and use the right math to sift through and restructure them, you can get good predictive results."

Dosenbach used data from five-minute MRI scans of 238 normal subjects ranging in age from 7 to 30. The support vector machine analyzed approximately 13,000 functional brain connections and selected the best 200 produce a single index of the maturity of each subject. The data allowed scientists to predict whether subjects were children or adults, and roughly formed a curving line that tracks the path of normal functional brain development.

The researchers suspect patients with brain disorders will appear out of alignment with this normal developmental curve.

"The beauty of this approach is that it lets you ask what's different in the way that children with autism, for example, are off the normal development curve versus the way children with attention-deficit disorder are off that curve," Schlaggar says.

Schlaggar suggests that functional brain scans might be conducted on a group of children at risk but not yet suffering from a developmental disorder.

"When a fraction of them later develop that disorder, you can go back and construct an analysis like this one that will help predict the characteristics of the next child at highest risk of developing the disorder," he says. "That's very powerful both clinically and from the perspective of understanding the causes of these disorders."

This approach might enable treatment prior to onset of symptoms, Schlaggar says, and should help physicians more quickly and closely track the results of clinical trials of new therapies.

"MRI scans are expensive, so this may not be what we use for everyone right now," Dosenbach says. "But many children with these types of disorders already receive regular structural MRI scans, and five more minutes in the scanner won't add that much to the cost."

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Scientists Succeed in Filming Organs and Joints in Real Time Using Magnetic Resonance Imaging

Scientists Succeed in Filming Organs and Joints in Real Time Using Magnetic Resonance Imaging

  11:20:00 PM    Science Lover

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"Please hold absolutely still": This instruction is crucial for patients being examined by magnetic resonance imaging (MRI). It is the only way to obtain clear images for diagnosis. Up to now, it was therefore almost impossible to image moving organs using MRI.

Real-time MRI of the heart with a measurement time of 33 
milliseconds per image and 30 images per second. The 
spatial resolution is 1.5 millimetres in the image plane 
(section thickness 8 millimetres). The eight successive 
images show the movement of the heart muscle of a healthy 
subject for a period of 0.264 seconds during a single 
heartbeat. The images range from the systolic phase 
(arrow, top left: contraction of the heart muscle) 
to the diastolic phase (arrow, bottom right: relaxation 
and expansion). The bright signal in the heart chambers 
is the blood. (Credit: Jens Frahm)

Max Planck researchers from Göttingen have now succeeded in significantly reducing the time required for recording images -- to just one fiftieth of a second. With this breakthrough, the dynamics of organs and joints can be filmed "live" for the first time: movements of the eye and jaw as well as the bending knee and the beating heart. The new MRI method promises to add important information about diseases of the joints and the heart. In many cases MRI examinations may become easier and more comfortable for patients.

A process that required several minutes until well into the 1980s, now only takes a matter of seconds: the recording of cross-sectional images of our body by magnetic resonance imaging (MRI). This was enabled by the FLASH (fast low angle shot) method developed by Göttingen scientists Jens Frahm and Axel Haase at the Max Planck Institute for Biophysical Chemistry. FLASH revolutionised MRI and was largely responsible for its establishment as a most important modality in diagnostic imaging. MRI is completely painless and, moreover, extremely safe. Because the technique works with magnetic fields and radio waves, patients are not subjected to any radiation exposure as is the case with X-rays. At present, however, the procedure is still too slow for the examination of rapidly moving organs and joints. For example, to trace the movement of the heart, the measurements must be synchronised with the electrocardiogram (ECG) while the patient holds the breath. Afterwards, the data from different heart beats have to be combined into a film.

Future prospect: extended diagnostics for diseases

The researchers working with Jens Frahm, Head of the non-profit "Biomedizinische NMR Forschungs GmbH," now succeeded in further accelerating the image acquisition process. The new MRI method developed by Jens Frahm, Martin Uecker and Shuo Zhang reduces the image acquisition time to one fiftieth of a second (20 milliseconds), making it possible to obtain "live recordings" of moving joints and organs at so far inaccessible temporal resolution and without artefacts. Filming the dynamics of the jaw during opening and closing of the mouth is just as easy as filming the movements involved in speech production or the rapid beating of the heart. "A real-time film of the heart enables us to directly monitor the pumping of the heart muscle and the resulting blood flow -- heartbeat by heartbeat and without the patient having to hold the breath," explains Frahm.

The scientists believe that the new method could help to improve the diagnosis of conditions such as coronary heart disease and myocardial insufficiency. Another application involves minimally invasive interventions which, thanks to this discovery, could be carried out in future using MRI instead of X-rays. "However, as it was the case with FLASH, we must first learn how to use the real-time MRI possibilities for medical purposes," says Frahm. "New challenges therefore also arise for doctors. The technical progress will have to be 'translated' into clinical protocols that provide optimum responses to the relevant medical questions."

Less is more: acceleration through better image reconstruction

To achieve the breakthrough to MRI measurement times that only take very small fractions of a second, several developments had to be successfully combined with each other. Whilst still relying on the FLASH technique, the scientists used a radial encoding of the spatial information which renders the images insensitive to movements. Mathematics was then required to further reduce the acquisition times. "Considerably fewer data are recorded than are usually necessary for the calculation of an image. We developed a new mathematical reconstruction technique which enables us to calculate a meaningful image from data which are, in fact, incomplete," explains Frahm. In the most extreme case it is possible to calculate an image of comparative quality out of just five percent of the data required for a normal image -- which corresponds to a reduction of the measurement time by a factor of 20. As a result, the Göttingen scientists have accelerated MRI from the mid 1980s by a factor of 10000.

Although these fast MRI measurements can be easily implemented on today's MRI devices, something of a bottleneck exists when it comes to the availability of sufficiently powerful computers for image reconstruction. Physicist Martin Uecker explains: "The computational effort required is gigantic. For example, if we examine the heart for only a minute in real time, between 2000 and 3000 images arise from a data volume of two gigabytes." Uecker consequently designed the mathematical process in such a way that it is divided into steps that can be calculated in parallel. These complex calculations are carried out using fast graphical processing units that were originally developed for computer games and three-dimensional visualization. "Our computer system requires about 30 minutes at present to process one minute's worth of film," says Uecker. Therefore, it will take a while until MRI systems are equipped with computers that will enable the immediate calculation and live presentation of the images during the scan.

In order to minimise the time their innovation will take to reach practical application, the Göttingen researchers are working in close cooperation with the company Siemens Healthcare.

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Gain and Loss in Optimistic Versus Pessimistic Brains

Gain and Loss in Optimistic Versus Pessimistic Brains

  9:28:00 PM    Science Lover

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Our belief as to whether we will likely succeed or fail at a given task -- and the consequences of winning or losing -- directly affects the levels of neural effort put forth in movement-planning circuits in the human cortex, according to a new brain-imaging study by neuroscientists at the California Institute of Technology (Caltech).

Subjects who reported they were "good" at the task 
(optimists) showed highest brain activity when they 
expected large gains; subjects who thought they 
performed "poorly" (pessimists) showed highest brain 
activity when they tried to avoid large losses. Yellow 
regions show brain areas with highest motor planning 
activity; green and red regions depict areas that 
exhibited the strongest modulation in activity 
relative to the subjective absolute value. 
(Credit: Igor Kagan/Caltech)

A paper about the research -- led by Richard A. Andersen, the James G. Boswell Professor of Neuroscience at Caltech -- appears in the August issue of PLoS Biology.

Research in Andersen's laboratory includes work to understand the neural mechanisms of action planning and decision-making. The lab is working toward the development of implanted neural prosthetic devices that would serve as an interface between severely paralyzed individuals' brain signals and artificial limbs -- allowing their planned actions to control the limbs' movements.

In particular, Andersen's group focuses on a high-level area of the brain called the posterior parietal cortex (PPC), where sensory stimuli are transformed into movement plans.

In the current study, Andersen and his colleagues used a functional magnetic resonance imaging scanner to monitor activity in the PPC and other brain areas in subjects who were asked to perform a complex task. Using a trackball, they had to move a cursor to a number of memorized locations on a computer screen, in a predetermined order.

"The subjects were given 1 second to memorize the sequence, 15 seconds to plan their movements in advance, and then only 10 seconds to finish the task," says Igor Kagan, a senior research fellow in biology in the Andersen lab, and a coauthor of the PLoS Biology paper. "We intentionally made the task hard -- I couldn't do it myself," he says.

The subjects received monetary compensation for participating in the experiment, with their earnings tied to their performance. The amount of money that would be gained (or lost) varied from trial to trial. In one trial, for example, success might net the participant $5, while failure would cause him to lose $1. In another trial, completing the task correctly would earn $1, while failure would cost $5. Alternatively, success and failure might produce an equivalent gain or loss (say, +$5 versus -$5). The subjects were told the stakes in advance of each trial.

Prior to receiving their earnings, the subjects reported -- in a post-test questionnaire -- how they perceived their performance. Interestingly, those perceptions did not correlate with their actual performance; individuals in the group who believed they had performed well were just as likely to have performed poorly, and vice versa for individuals in the group who believed they had done badly.

Furthermore, the researchers found that the pattern of brain activity in the PPC was linked to how well the subjects believed they had done on the tasks -- that is, their subjective perception of their performance, rather than their actual performance -- as well as by the monetary gain or loss they expected from success or failure.

How hard an individual subject's brain "worked" at the task was dependent upon their personal approach. For example, Andersen says, "subjects who are 'optimists' and believe they are doing well will put out the most effort -- and exhibit an increase in activity in their PPC -- when they expect to earn a larger reward for being successful." Conversely, those individuals who believe they are doing poorly -- the pessimists -- show the most brain activity when there is a higher price for failure.

"They're trying harder to avoid losses and seem to care less about potential gains," Kagan adds.

"This study demonstrates that the process of planning and action is influenced by our subjective, but often incorrect, idea of how well we are doing, as well as by the potential gain or loss," Andersen says. The results suggest that the cortical areas involved in planning actions are also likely to be involved in decision-making, and take into account higher-order cognitive as well as subjective factors when deciding among potential actions.

The paper was also coauthored by former Caltech graduate student Asha Iyer, the first author of the study, now a resident at Mount Sinai Medical School, and former Caltech postdoctoral fellow Axel Lindner, now a group leader at the University of Tübingen. The research was funded by the Gordon and Betty Moore Foundation, the James G. Boswell Foundation, and the National Eye Institute.

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