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Science stories will now be at http://en.wikinews.org/, and will have a flexible schedule of two or three stories per week.

Science news is taking a break this week.

Researchers with the University of Calgary in Canada have found that prolactin, a hormone produced during pregnancy, may reverse the progression of multiple sclerosis (MS), according to a paper published this week in The Journal of Neuroscience.

MS is an autoimmune disease of the central nervous system where the body attacks the fatty myelin which helps nerves carry electrical signals, causing muscle weakness and spasming which may lead to disability. MS affects approximately one of every 1000 people in North America, northern Europe and Australasia.

The study, led by Drs. Samuel Weiss and V. Wee Yong of the Hotchkiss Brain Institute, compared virgin and pregnant mice with MS-like lesions introduced by lysolecithin, a chemical which destroys the myelin sheaths around neurons. They found the pregnant mice developed smaller lesions and fewer damaged neurons, and showed signs of repaired neurons. They also found the pregnant mice had higher levels of cells called oligodendrocytes, which create myelin and are able to repair some damaged neurons through reymyelination. Because prolactin regulates the levels of precursors of oligodendrocytes, the scientists hypothesized that prolactin levels were responsible for the differences in damage. They also tested virgin mice given additional prolactin, and found results similar to pregnant mice.

Previous studies have shown that other hormones could reduce myelin damage, but this is the first study to show a mechanism to reverse myelin damage, and establish an empirical connection between that mechanism and pregnancy. Dr. Weiss says, “It is thought that during pregnancy, women’s immune systems no longer destroyed the myelin. However, no previous study has tested whether pregnancy actually results in the production of new myelin, which may lead to improvement of symptoms. "We're excited about this result because it suggests to us that prolactin has the potential to be used to enhance the production of new myelin.”

Dr. William McIlroy, national medical advisor for the Multiple Sclerosis Society of Canada, explains the significance of this study: “The results of this study should be well received by people living with MS today. It represents a new insight of how we might be able to reverse some of the effects of the disease and improve the quality of life for those who live under its influence.”

Dr. Luanne Metz, director of the Calgary MS Clinic in the Department of Clinical Neurosciences, University of Calgary and Calgary Health Region, adds, “This discovery has the potential to take MS therapy a step further than current treatments that stabilize the disease in its early stages. By promoting repair, which is the goal of prolactin therapy, we have hope of actually improving symptoms in people with MS.”

Further animal studies need to be done to examine the possibility of side effects, such as lactation in men and non-pregnant women, as well as increased inflammation which could worsen the MS. Researchers believe human trials may begin within a few years.

Funding and support were provided by the Canadian Institutes of Health Research and the Multiple Sclerosis Society of Canada, the Alberta Heritage Foundation for Medical Research and the Stem Cell Network.

Sources

* Christopher Gregg, Viktor Shikar, Peter Larsen, Gloria Mak, Andrew Chojnacki, V. Wee Yong, and Samuel Weiss. Myelination and Remyelination in the Pregnant Mouse. The Journal of Neuroscience, 2007; 27(8): 1812-1823. PubMed
* "This Week in The Journal". The Journal of Neuroscience, February 21, 2007
* "Pregnancy Hormone Key To Repairing Nerve Cell Damage". University of Calgary, February 20, 2007
* Roxanne Khamsi "Pregnancy hormone reverses MS damage". New Scientist, February 21, 2007

NASA's Spitzer Space Telescope made news this week when it was announced that the space observatory had, for the first time, captured enough light to detect molecules in the atmospheres of planets outside our solar system.

The planets are too far away to be observed directly with current technology, but by measuring the spectra of each planet when visible with its star, and again when the planet was hidden behind its star, the teams were able to determine the measurements of the planets spectra.

In a paper published in the February 22 issue of Nature, Dr. Jeremy Richardson of NASA's Goddard Space Flight Center presented measurements of HD 209458 b, a hot, Jupiter-like planet located 153 light-years from Earth, in the constellation Pegasus. Richardson's team found a peak in the infrared spectra and was able to determine that the atmosphere of HD 209458 b likely consisted of clouds of silicate dust. Dr. Mark Swain of the Jet Propulsion Laboratory led another study of HD 209458 b, and found similar results.

Another team, led by Dr. Carl Grillmair of Spitzer Science Center at Caltech, performed a similar study of HD 189733b, 63 light-years away, in the constellation Vulpecula. Dr. Grillmair discusses the results: “It was believed to be fairly straightforward that these planets would have a lot of water in them, for one thing, very hot water. These planets, these hot Jupiters very, very close in to their parent stars are 2,000 degrees Fahrenheit or so, so it's not a pleasant place to live. And what we found instead and what the other group found for this completely different planet around another star, is that the spectrum is essentially flat. It really doesn’t show any of the features we would have expected from water.”

"The theorists' heads were spinning when they saw the data," adds Dr. Richardson. "It is virtually impossible for water, in the form of vapor, to be absent from the planet, so it must be hidden, probably by the dusty cloud layer we detected in our spectrum."

Dr. Grillmair: “The observations are showing us that things are not the way we expected them. And so there'll be a big push to get a lot more data while Spitzer is still alive. I think this will ultimately be one of the most important legacies of the Spitzer Space Telescope, unanticipated as it was before launch. I think it will become extremely important in the future.”

"With these new observations, we are refining the tools that we will one day need to find life elsewhere if it exists," said Swain. "It's sort of like a dress rehearsal."

Dr. Swain's and Dr. Grillmair's studies are pending publication in Astrophysical Journal Letters.

Sources
* L. Jeremy Richardson, Drake Deming, Karen Horning, Sara Seager and Joseph Harrington "A spectrum of an extrasolar planet". Nature, February 22, 2007
* C. J. Grillmair, D. Charbonneau, A. Burrows, L. Armus, J. Stauffer, V. Meadows, J. van Cleve, D. Levine "A Spitzer Spectrum of the Exoplanet HD 189733b". arXiv, February 19, 2007
* M.R. Swain, J. Bouwman, R. Akeson, S. Lawler, C. Beichman "The mid-infrared spectrum of the transiting exoplanet HD 209458b". arXiv, February 21, 2007
* "NASA's Spitzer First to Crack Open Light of Far Away Worlds". NASA, February 21, 2007
* "Hot, Dry and Cloudy". NASA, February 21, 2007
* "Hunting for Molecules on Faraway Planets". JPL, February 21, 2007

Denial. Anger. Bargaining. Depression. Acceptance.

Originally formulated in 1973 by Elisabeth Kübler-Ross, these five stages are well-known to many as the "Five Stages of Grief". However, despite their familiarity, the five-stage theory had remained untested empirically, until Paul K. Maciejewski, Ph.D., assistant professor of psychiatry at the Yale University School of Medicine and the Yale Bereavement Study completed several years of research, findings for which were published in the February 21 issue of the Journal of the American Medical Association.

According to Dr. Kübler-Ross's theory, denial is the first and most defining indicator of grief. The Yale Bereavement Study's findings, in contrast, show acceptance to be the most common indicator, and yearning the strongest negative indicator.

The authors explain, "Disbelief decreased from an initial high at one month postloss, yearning peaked at four months postloss, anger peaked at five months postloss, and depression peaked at six months postloss. Acceptance increased steadily through the study observation period ending at 24 months postloss.”

Study author Holly Prigerson, associate professor of psychiatry at Harvard Medical School and director of the Dana-Farber Cancer Institute's Center for Psycho-Oncology and Palliative Care Research, says, "This would suggest that people who have extreme levels of depression, anger or yearning beyond six months would be those who might benefit from a better mental health evaluation and possible referral for treatment."

The Yale Bereavement Study followed the progress of 233 participants from January 2000 through January 2003 who had lost family, most often a spouse, and was funded by the National Institute of Mental Health, the National Cancer Institute, the National Institute of Neurological Disorders and Stroke, the Center for Psycho-Oncology and Palliative Care Research, Dana-Farber Cancer Institute, and Women’s Health Research at Yale University.

Sources
Kubler-Ross, E (1973) On Death and Dying, Routledge, ISBN 0415040159
Paul K. Maciejewski, PhD; Baohui Zhang, MS; Susan D. Block, MD; Holly G. Prigerson, PhD "An Empirical Examination of the Stage Theory of Grief". JAMA, February 21, 2007
Ronald Kotulak "Scientists measure 5 stages of grief". Chicago Tribune, February 20, 2007

In the largest study of its kind, a genetic analysis of 1 200 families with multiple cases of autism has identified two genetic links to autism, one on chromosome 11 and another in a gene family called neurexin 1.

Genetic studies of autism had previously been attempted; however the new study involves the collaboration of more than 120 scientists from more than 50 institutions representing 19 countries who pooled their data as part of the Autism Genome Project.

Bob Wright, co-founder of Autism Speaks, a nonprofit organization dedicated to increasing awareness of autism, said: "The identification of susceptibility genes will provide profound new insight into the basis of autism offering a route to breakthroughs in new treatments in support of families." Autism Speaks funded this project in conjunction with the US National Institutes of Health.

Joachim Hallmayer, MD, associate professor of psychiatry at Stanford and chair of the collaboration's executive committee, explains what is next, “While promising, these results need to be followed up with more refined genetic maps to home in on other specific candidate genes. We also need to look more closely at chromosomal anomalies in large samples of children with autism.”

The findings were published in the Feb. 18 issue of Nature Genetics.

The HiRISE camera aboard NASA's Mars Reconnaissance Orbiter has found new evidence that liquids flowed on the surface of Mars, according to a report published in Science on Feb. 16.

In the paper, Chris Okubo of the University of Arizona's Lunar and Planetary Laboratory and Alfred McEwen, professor of planetary science at the University of Arizona and principal investigator for HiRISE (the High Resolution Imaging Science Experiment) discuss findings of fractures found in Candor Chasma, part of the vast network of canyons known as Valles Marineris. Although the origin of the fractures, which may be several kilometers in length, remains a mystery, discoloration of the rock along the fracture indicates that a fluid, believed to be water, carbon dioxide, or both, flowed through the fractures.

"What caught my eye was the bleaching or lack of dark material along the fracture. That is a sign of mineral alteration by fluids that moved through those joints," said Okubo. "It reminded me of something I had seen during field studies in Utah, that is light-tone zones, or 'haloes,' on either side of cracks through darker sandstone."

"It is hard to say how long ago the fluids were there - hundreds of millions or perhaps a billion years ago. But the fact that we see evidence for chemical reactions between the fluids and the rock means that the fluids were sitting there for quite a long time ... that's perhaps good if you want to look for any habitable areas that might support any biological activity," added Okubo.

"Never before have we seen such a massive differentiation of stem cells into neurons in the spinal cord," said Vassilis Koliatsos, M.D., associate professor of neuropathology at The Johns Hopkins Medical Institutions, discussing results published this week at PLoS Medicine. In the study, Dr. Koliatsos's team grafted human neural stem cells (hNSCs) into rats with spinal cord injuries. The found that the hNSCs became neurons, and connected with the gray and white matter in the rats spinal cord.

Scientists had previously believed that the spinal cord was incapable of repairing itself. "This turns on its head the dogma that the spinal cord isn't an effective environment for turning stem cells into neurons. Additionally, a significant number of these neurons went on to engage in synaptic relationships with the host neurons. To what extent these contacts are functional synapses or signify structural integration into the host circuitry must be ascertained with additional studies," Dr. Koliatsos explained.

Adds Dr. Karl Johe, Scientific Founder and Chairman of Neuralstem (developer of the stem cells) and a co-author of the study, "When combined with our earlier spinal cord work in rats with ALS (Lou Gehrig's disease), we now believe that the spinal cord is an effective site for therapeutic stem cell intervention."

Says Dr. Koliatsos, "We don't yet know whether the connections we've seen can transmit nerve signals to the degree that a rat could be made to walk again. We're still in the proof of concept stage, but we're encouraged."

Article:

Extensive Neuronal Differentiation of Human Neural Stem Cell Grafts in Adult Rat Spinal Cord
Yan J, Xu L, Welsh AM, Hatfield G, Hazel T, et al.
PLoS Medicine Vol. 4, No. 2, e39 doi:10.1371/journal.pmed.0040039

Chili peppers have been a part of the human diet for at least 6 000 years, according to a report to be published in tomorrow's Science.

A international team of scientists lead by anthropologist Linda Perry of the Smithsonian National Museum of Natural History in Washington, DC, identified fossilized grains of starch that were eventually identified as belonging to domesticated Capsicum chilis.

Antropologist Deborah Pearsall of the University of Missouri-Columbia, who was part of the research team, explains: "Chili peppers don't preserve well because when you cook with them, you eat most of them; you don't have husks or shells that are thrown away and preserved. That's why we used a technique that involved analysing microscopic starch grains on cooking and grinding tools to find this new evidence."

Although the microfossils are found from the Bahamas to Peru, in some cases predating pottery, the oldest specimens were found in the lowland rainforests of western Ecuador. Previous research had established that chilis are native only to areas east of the Andes, and the details of transport into Ecuador remain unanswered.

The European Space Agency's Cluster satellites have been probing Earth's aurorae. Recent interpretations of their data explain the difference between the two types of auroral arcs.

The aurorae are created in much the same way as images on an old, tube-style television set. Electrons in the TV are launched by means of a magnetic gun at the screen. They light up when they collide with the phosphors. Similarly, electrons near Earth are launched by the magnetosphere toward the Earth. They light up when they collide with atoms and molecules in the atmosphere. Vast waves of electric potential energy undergoing this process results in the polar lights that have for so long fascinated mankind.

The lights are generally described as being symmetric (U-shaped) or asymmetric (S-shaped). Prof. Göran Marklund from the Alfvén Laboratory, at the Royal Institute of Technology, Stockholm, Sweden, had previously observed that the shape of the structure seemed to depend on location. He identified this relation as occurring at boundaries of plasma layers -- the symmetric auroral arcs occurred most often at the boundary of the "central plasma sheet", nearer the equator, and the "plasma sheet boundary layer", nearer the poles. The asymmetric arcs occurred at the boundary of the "plasma sheet boundary layer" and the polar cap.

In 2003, two of the Cluster satellites passed through the same point, crossing from the "central plasma sheet" to the "plasma sheet boundary layer", only 16 minutes apart. The first satellite observed a symmetric potential; the second, an asymmetric potential. The satellites also observed that, in the 16 minutes, plasma density and flux decreased significantly.

The observations increase our understanding of the difference between the plasma layers, but still don't explain why auroras start in the first place. A later phase of the Cluster project is planned to study this aspect.

The results, by Marklund et al., were published in the 13 January 2007 issue of the Journal of Geophysical Research.

In an article in the February issue of Current Directions in Psychological Science, Gary Wells and Lisa Hasels of Iowa State University contend that most of the technologically advanced facial compositing tools utilized by law enforcement agencies have failed to improve our ability to identify criminals.

The problem, the authors claim, stems from the fact that these tools do not account for knowledge about how facial recognition works in humans. "Numerous lines of evidence converge on the view that faces are generally processed, stored, and retrieved at a holistic level rather than at the level of individual facial features." The brain's method of processing a whole face undermines any technique built upon a feature-by-feature compositing. "Imagine the solace of the culprit who sees a composite of his face in the newspaper that looks nothing like his face," says Wells.

Fortunately, better knowledge of how the brain recognizes faces may yield a better compositing tool, one based around treating a whole face holistically. Systems currently in testing begin by generating a random set of faces, from which the witness selects the best match. Then, using that as a "seed", the system generates a set of variations. This process continues until the witness arrives, finally, at the face that matches their recollection of the criminal.

In findings published online Feb. 11 by the journal Nature Physics, researchers from Northwestern University identify a new compound -- Bi-2212, made from bismuth -- as a candidate for a new class of superconducting magnet wire.

The compound currently used in MRI machines, made from niobium, can be pushed to a magnetic intensity of 21 Tesla, at 4 degrees Kelvin. Bi-2212, in comparison, begins to exhibit superconductivity at 90 degrees Kelvin, and becomes stable at 12 degrees Kelvin. It could also achieve at magnetic intensity of 30 Tesla.

According to team lead William P. Halperin, Professor of Physics and Astronomy in the Weinberg College of Arts and Sciences, "In MR imaging, the higher the magnetic field, the higher the resolution, which provides scientists with more detail for analysis. A 30 Tesla magnet could drive significant advances in chemistry, biology and medicine."

"We are exploring nature's limitations, and our discovery has basic implications for the study of superconductors and for applications to magnetic resonance imaging. The dream would be to have powerful magnets that don't require helium for cooling. Some day new materials might be discovered where this restriction is lifted, but it isn't possible at the present time."

The most common human pathogen, Helicobacter pylori, which is responsible for stomach ulcers, has been infecting humans for at least 60,000 years, a report published Wednesday in Nature shows.

The study, led by Dr Francois Balloux of the University of Cambridge, analyzed the genetic variations between strains of the bacteria, and compared the results to human migratory patterns. They found that genetic variability in humans matched that of H. pylori.

Dr. Balloux: "Humans and this ulcer-causing bacterium have been intimately linked for the last 60,000 years. The research not only shows the likelihood that for tens of thousands of years our ancestors have been suffering the effects of this bacteria but it also opens up new possibilities for understanding early human migration. By showing that Helicobacter pylori emerged from Africa at the same time as early humans it makes it easier to examine some of the controversial questions about human migration. For example we could use our understanding of the bacteria's spread to gauge poorly understood human population shifts in Europe, Africa and Asia."

Rett Syndrome (RTT) is a pervasive neurodevelopmental disorder, related to autism, which causes breathing, motor and speech problems, mostly in girls, with no known cure. It is caused by mutations in the MECP2 gene.

Dr. Adrian Bird, of the University of Edinburgh and Chairman of the Rett Syndrome Research Foundation Scientific Advisory Board, announced today in a paper appearing online in Science Express results of an experimental technique to reverse RTT in mice.

In the study, mice were given RTT symptoms through introduction of a genetic block into their MECP2 gene. After the symptoms had developed, the reversal was accomplished by triggering an enzyme to snip out the genetic block, restoring the MECP2 to normalcy.

"Like many other people, we expected that giving MECP2 to mice that were already sick would not work," said Bird. "The idea that you could put back an essential component after the damage to the brain is done and recover an apparently normal mouse seemed farfetched, as nerve cells that developed in the absence of a key component were assumed to be irrevocably damaged."

Not only did the treatment reverse many of the symptoms, it appeared to improve the ability of the brain to develop. "We expected that at best we'd get a reduction in the severity of the symptoms. To have them go away virtually completely was a big surprise."

MECP2 is implicated in many other disorders, from autism to schizophrenia. Bird's findings clear the way for many avenues of research and potential treatments.

Before After

Journal reference: Science (DOI: 10.1126/science.1138389)

A flash.

A pulse of laser light leaves its emitter. It travels slowly. Here, the speed of light is tens of miles per hour.

Ahead, a cloud hangs in the air. This cloud, made of sodium atoms, is very cold – almost absolute zero. This cloud is not a gas, but rather an exotic form of matter discovered only a decade ago. It is called Bose-Einstein condensate.

In this cloud, quantum effects dominate.

The slow laser finally encounters the quantum cloud. The light stops. The cloud twitches. Atoms within the Bose-Einstein condensate have captured the energy from the laser.

“It’s really playing with quantum mechanics at a lot of different levels,” says physicist Lene Hau of Harvard University. She and her co-authors, Naomi Ginsberg and Sean Garner, report the results of this experiment in today’s Nature.

The team turns off a second laser, which has been controlling the vibrating condensate in place, and allow the atoms to drift 160 microns to a second cloud of condensate.

When the control laser is reactivated, the vibrating atoms from the first cloud are forced to dump their energy into the second cloud. The original laser pulse is reconstructed.

Dr. Hau: “We demonstrate that we can stop a light pulse in a supercooled sodium cloud, store the data contained within it, and totally extinguish it, only to reincarnate the pulse in another cloud two-tenths of a millimeter away. This work could provide a missing link in the control of optical information. While the matter is traveling between the two Bose-Einstein condensates, we can trap it, potentially for minutes, and reshape it – change it – in whatever way we want. This novel form of quantum control could also have applications in the developing fields of quantum information processing and quantum cryptography.”

In the cold, dark depths of the ocean floor, where sunlight doesn't reach, a monster lies in wait. It's a plume of volcanically heated water, rich in sulfur and methane, called a black smoker. At up to 750 F, it'll make short work of most anything that gets too close.

Fortunately for sea life, it is not a silent killer.

Doctoral student in oceanography Timothy Crone, of the University of Washington, has captured the sounds of the black smoker. As he discusses in a paper published in December in the Public Library of Sciences' online journal, PLoS ONE, the turbulent, mineral-rich flows generate a rumble, which likely warns most fish away.

Crone has been studying the sounds produced by the hydrothermal vents as a way of measuring the activity of the flows. As a result of the extreme conditions found within the flows, very few measuring devices can be used for long. The sounds, however, can be measured from several meters away.

Hidden within the rumble are many resonant tones. "With these resonant tones, each vent within the event field is likely to have its own unique acoustic signature," says Crone. This acoustic signature may capture such information as shape of the vent, fluid pressure, and tidal variability.

More sounds and a link to the article may be found here.

For almost one hundred years, scientists have struggled to reconcile Einstein's general relativity with quantum mechanics into a "Theory of Everything". String theory shows promise in achieving this goal, but only if our universe is ten-dimensional. Of course, we are all familiar with the three dimensions of space and the one of time. Physicists think that perhaps the reason we can't perceive the other six dimensions is that they have all compacted to extremely small shapes.

Physicist Gary Shiu, of the University of Wisconsin Madison, thinks he's figured out a way of determining what shapes these dimensions may be.

As they explain in the February 2 Physical Review Letters, Shiu and graduate student Bret Underwood surmised that the other dimensions would have had the greatest effect on our four-dimensional spacetime at the time of the Big Bang, when the universe expanded rapidly from a point. At that time, all 10 dimensions would have been at the same scale and able to interact.

"Our idea was to go back in time and see what happened back then," says Shiu. "Of course, we couldn't really go back in time." Fortunately for Shiu, because light takes time to travel, observing extremely distant features of the universe is like going back in time.

NASA's Wilkinson Microwave Anisotropy Probe (WMAP) has mapped the energy from the farthest reaches of space. Shiu compares this map to "a snapshot of the baby universe". Although the WMAP data is not detailed enough to show us the shapes of the collapsed dimensions, Shiu has been able to compare the patterns of energy to some simpler geometric shapes and show that the technique is workable.

"Our results with simple, well-understood shapes give proof of concept that the geometry of hidden dimensions can be deciphered from the pattern of cosmic energy. This provides a rare opportunity in which string theory can be tested."

Improved experiments, such as the European Space Agency's Planck satellite, should provide the detailed data necessary to determine the shapes of these dimensions.

The so-called "high-low" (high nutrients, low calories) diet, or "CRON" (calorie restriction with optimal nutrition), has been shown in many species, from rats to roundworms, to extend maximum lifespan. However, a new study has shown, at least in fruit flies, that just smelling food can be enough to reverse some of the benefit.

In a paper published online in yesterday's Science Express, Scott Pletcher of the Baylor College of Medicine in Houston, Texas, discussed this discovery. Scientists already knew that the fruit fly, Drosophila melanogaster, lived about 45 days when fed a normal diet, 35 days when allowed to eat as much as they wanted, and about 55 days on the optimized diet. Observations that fruit flies switched from a normal diet to a optimized diet experienced immediate lifespan extension suggested that smell was involved.

Dr. Pletcher's team tested normal fruit flies on an optimized diet by exposing them to the scent of live yeast, a favorite food of the fruit fly. Their maximum lifespan decreased from 6 to 18 percent, which confirms the importance of smell. They also tested a mutant fly with a greatly reduced sense of smell. The mutants lived about 75 days, regardless of their diet.

While the mechanism behind this action remains unknown, scientists theorize that the increased longevity from reduced calories may have developed as a survival strategy against famine. This theory could also explain the team's findings.

Lead author Sergiy Libert explains, "There may be a signaling mechanism that makes the organism operate more robustly when there are few resources. Activating that signaling might be enough to provide the advantage and extend longevity. Flies that could smell rich food in the environment lived shorter lives than flies who ate the same amount of food but were not exposed to the odorant. The perception of a rich environment was sufficient to shorten the lifespan."

While it's still too early to know what these findings may mean in humans, the research could lead to new medical breakthroughs.

References
1. Libert S., et al. Science, doi:10.1126/science.1136610 (2006).

It’s long been a scientific riddle how our brains measure time. The prevailing theory for the last few decades holds that there was some mechanism within the brain, perhaps cells that fired at a constant rate, that acted as a clock.

Now, Dean Buonomano, associate professor of neurobiology and psychiatry at the David Geffen School of Medicine at the University of California Los Angeles, provides evidence that the prevailing theory is wrong. In a paper published in today’s Neuron, Dr. Buonomano details a study that shows that the brain relies on external cues.

The study asked volunteers to judge the amount of time between to sounds. The researchers were able to disrupt the volunteers’ timing by preceding the test tones with a distracter tone.

By analogy with tossing pebbles into a lake, Dr. Buonomano explains, “the ripples of water produced by the pebble’s impact act like a signature of the pebble’s entry time. The farther the ripples travel, the more time has passed.” Similarly, the brain seems able to measure “ripples” of activity to determine the amount of time since the brain processed a sensory event.

However, if you toss a pebble right before the pebble you want to measure, the two sets of ripples will be hard to separate, and will interfere with the act of measuring. In Dr. Buonomano’s study, a sound introduced right before the timed sounds appears to interfere with the patterns in the brain used to keep time.

“Our results suggest that the timing mechanisms that underlie our ability to recognize speech and enjoy music are distributed throughout the brain, and do not resemble the conventional clocks we wear on our wrists,” said Dr. Buonomano.

Further research into this mechanism may lead to new treatments for
disorders believed to result in a timing disorder, such as dyslexia.