University News
UC Merced Grand Opening Set for September 5
The University of California, Merced - the first new University of California campus since 1965 and the first ever in California's sprawling San Joaquin Valley - will officially open its doors September 5 in a Grand Opening ceremony featuring senior university officials, members of the UC Board of Regents and the inaugural class of 1,000 students.
"We couldn't be more excited," said Carol Tomlinson-Keasey, who was named chancellor of UC Merced in 1999 and has spearheaded its development ever since. "Our faculty is in place, student housing is ready, essential services are rapidly coming on line and the welcome mat is out. This is a very special moment for everyone involved in bringing this new campus to life."
UC Merced is the 10th campus in the University of California system, recognized globally as one of the world's leading public university systems. Based on projections of rapid population growth throughout the state, UC Regents first proposed adding a 10th campus to the system in 1988. Merced was chosen as the site in 1995 after a rigorous screening process that included more than 80 different locations.
"This new campus will allow California to fulfill the promise of access to qualified students from all over the state, as our first class clearly illustrates," said Tomlinson-Keasey. "A thriving research university will create a new level of opportunity for UC-eligible men and women for generations to come while stimulating economic growth, creating jobs, spawning new industries and addressing tough societal challenges."
UC Merced's first 1,000 students come from as far north as California's most northern county of Del Norte, as far south as San Diego, as far east as the Sierra Nevada and as far west as the Pacific Coast, according to university admission records. About half are the first in their families to attend college. Nearly 25 percent report annual family incomes below $30,000, and approximately one-third are from underrepresented ethnic or racial minority groups. All met the University of California's rigorous admission requirements.
"We're delighted with the academic credentials, diverse backgrounds and pioneering spirit of our inaugural class," said Tomlinson-Keasey. "These young scholars, including 38 graduate students, will play a major role in shaping the campus lifestyle, founding student organizations and defining the character of a major research university. They'll work closely with our world-class faculty and benefit from academic programming that is focused on real-world challenges of the 21st century. We're thrilled to have this chance to deliver UC-quality academics in a new and welcoming environment that will inspire and produce the leaders of tomorrow."
UC Merced will grow rapidly over the coming years, with total enrollment expected to reach about 5,000 by 2010 and top out at 25,000 in 2035. The university initially will offer undergraduate degrees in nine different majors from three disciplines - engineering; natural sciences; and social sciences, humanities and the arts. Graduate degrees in these same fields also are available. Degree offerings will expand rapidly as the university grows.
Opening ceremonies on September 5 will begin at 10 a.m. at the permanent campus site just south of Lake Yosemite, five miles from downtown Merced. The invitation-only event will include comments from Gerald Parsky, chair of the UC Board of Regents, UC President Robert Dynes and Chancellor Tomlinson-Keasey. Keynote remarks will be delivered by Merced native Charles Ogletree, professor and director of Harvard Law School's Charles Hamilton Houston Institute for Race and Justice.
"Reaching this milestone required the commitment of multiple governors, UC presidents, and state and federal legislators," said Tomlinson-Keasey. "Celebrating this moment will be past Governors George Deukmejian and Gray Davis, past Presidents Richard Atkinson and David Gardner, as well as numerous elected officials who have supported us throughout the years."
The campus will open to the public in the afternoon as of 1 p.m. that day.
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UW Engineering Creates University's First Deanship with $4 Million Gift
A $4 million donation from Frank and Julie Jungers will create an endowed deanship in the University of Washington's College of Engineering. This is the first endowed deanship ever created at the UW.
Frank Jungers graduated from the UW in 1947 with a degree in mechanical engineering. He spent most of his career in Saudi Arabia, ultimately serving as chairman and CEO of Aramco, the Arabian American Oil Company, one of the largest oil corporations in the world.
For many years Jungers has been a generous donor to--and an active volunteer for--the UW, particularly the College of Engineering. In 1987 he established the Frank Jungers Endowed Professorship in the college. Through additional gifts, he increased that professorship to a chair.
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Planet Hunter Geoffrey Marcy Shares $1 million Shaw Prize in Astronomy
Astronomer Geoffrey Marcy's tenacious pursuit of planets outside our solar system has paid off with the discovery by him and his team of more than 110 extrasolar planets.
Now, that doggedness is paying off in another way. On Friday, Sept. 2, he will receive $500,000 from the Hong Kong-based Shaw Prize Foundation in recognition of his pioneering achievements.
Marcy, professor of astronomy at the University of California, Berkeley, and director of the campus's Center for Integrative Planetary Science, will share the $1 million Shaw Prize in astronomy with Michel Mayor of the University of Geneva for "finding and characterizing the orbits and masses of the first planets around other stars, thereby revolutionizing our understanding of the processes that form planets and planetary systems."
This is only the second year the three Shaw Prizes have been awarded, honoring scholars in the fields of astronomy, mathematics and life science and medicine. They were established under the auspices of Sir Run Run Shaw, a Hong Kong film producer and current chairman of Television Broadcasts Limited (TVB), the largest Chinese program producer in the world. The prize, sometimes referred to as the "Nobel Prize of the East," honors individuals who have achieved significant breakthroughs in academic and scientific research or application and whose work has resulted in a positive and profound impact on mankind.
Marcy emphasized that the achievements for which he's being honored were the product of a team effort, in particular a close collaboration with Paul Butler of the Carnegie Institution of Washington.
Credit also goes to Steve Vogt, professor of astronomy at UC Santa Cruz, who designed and built the spectrometers used to discover planets, and recently, Debra Fischer, assistant professor of astronomy at San Francisco State University, who contributed "incredibly innovative ideas for planet-hunting, especially the most recent discovery that our planets have large cores of rocky material in their centers."
Marcy plans to donate $400,000 to UC Berkeley to continue research on other planetary systems. He also is giving $50,000 to San Francisco State University, where he and Butler started their planet searches in 1987 and which "gave me my start as a professor," he said.
Michel Mayor, with whom Marcy shares the Shaw Prize, reported the first extrasolar planet in October 1995, based on observations with Didier Queloz at the Geneva Observatory in Switzerland. Within a week, Marcy and Butler had confirmed the planet through observations at the University of California's Lick Observatory, opening a floodgate of new-found planets from his group. To date, more than 150 planets have been reported, the majority of them by Marcy, Butler, Fischer and Vogt.
The Shaw Prize, an international award managed and administered by The Shaw Prize Foundation of Hong Kong, is accompanied by a medal displaying a portrait of Sir Run Run Shaw and the imprint of a Chinese phrase from Xun Zi, a thinker in the warring states period of Chinese history in 313 to 238 B.C. The phrase translates as "Grasp the law of nature and make use of it."
Awarded the Shaw Prize this year in the area of life science and medicine was Professor Sir Michael Berridge of Babraham Institute, Cambridge, United Kingdom, "for his discoveries on calcium signaling in the regulation of cellular activity." Professor Andrew John Wiles of Princeton University was awarded the Shaw Prize in mathematics for his proof of Fermat's Last Theorem.
Last year's winner of the mathematics prize was the late UC Berkeley professor emeritus of mathematics Shiing Shen Chern "for his initiation of the field of global differential geometry and his continued leadership of the field ... ."
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Adult Cells Transformed into Stem Cells
A new type of hybrid cell created at Harvard University could eventually solve the mystery of how embryonic stem cells develop into specialized adult cells, and provide genetically tailored treatments for many human diseases.
What's more, the technique holds out the possibility of doing this without creating or destroying human embryos.
The researchers fused adult skin cells with embryonic stem cells in such a way that the genes of the embryonic cells reset the genetic clock of the adult cells, turning them back to their embryonic form.
Such adult-cum-embryo cells, taken from people with juvenile diabetes, Parkinson's, Alzheimer's, and other genetic diseases, could reveal how such diseases develop and provide novel treatment for them. For example, normal cells might be made to replace abnormal ones that cause juvenile diabetes and Alzheimer's disease. It should be possible to coax these newly created embryonic cells "into replacement cells and even organs," says biologist Chad Cowan who participated in the experiments. "But it would definitely not be possible to clone the person from which the adult cell came."
Cowan is the lead author of a report of the research published in the August 26 issue of Science. The other authors are Kevin Eggan, Douglas Melton, and Jocelyn Atienza of the Harvard Stem Cell Institute.
The next step is to puzzle out how an embryonic cell can turn back, or reprogram, the genes of an adult cell. That could take 10 years, Cowan guesses. "But is will eventually happen, and it will mean scratching at some of biology's fundamental questions in the process," he says.
However, this long-term scratching at the fundamentals does not have to delay the use of hybrid cells for helping patients. The quickest way to new treatments, the researchers believe, is finding a way to remove the embryonic DNA.
The hybrid cells contain two sets of DNA, or genes, one from the reprogrammed adult cell and one from the embryonic "starter" cell. To track disease development, experimenters need to excise the latter. That done, they can determine how the adult cells differentiate into diseased cells and tissues.
The Harvard group obtained the starter cells by growing embryos from excess fertilized cells acquired from fertilization clinics with the owners' permission. Using such materials, Douglas Melton, the Thomas Dudley Cabot Professor of the Natural Sciences in the Faculty of Arts and Sciences and co-director of the Harvard Stem Cell Institute, has created at least 17 new lines of embryonic stem cells using private funds (see March 4, 2004 Gazette). These are not part of the cell lines eligible for federal funding.
The new work on hybrids was done using stem cells made by Melton, then some of the experiments were repeated with a federally approved line of cells. The adult cells came from foreskin and pelvic areas.
When all the problems are solved, the Harvard team sees a new source of stem cells produced without the need to create or destroy embryos that some people insist are "alive."
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Successful Testing - a Solution for Production of Hydrogen Fuel Through Solar Technology
Innovative solar technology that may offer a 'green' solution to the production of hydrogen fuel has been successfully tested on a large scale at the Weizmann Institute of Science in Israel. The technology also promises to facilitate the storage and transportation of hydrogen. The chemical process behind the technology was originally developed at Weizmann, and it has been scaled up in collaboration with European scientists. Results of the experiments will be reported in August at the 2005 Solar World Congress of the International Solar Energy Society (ISES) in Orlando, Florida.
The solar project is the result of collaboration between scientists from the Weizmann Institute of Science, the Swiss Federal Institute of Technology, Paul Scherrer Institute in Switzerland, Institut de Science et de Genie des Materiaux et Procedes - Centre National de la Recherche Scientifique in France, and the ScanArc Plasma Technologies AB in Sweden. The project is supported by the European Union's FP5 program.
Hydrogen, the most plentiful element in the universe, is an attractive candidate for becoming a pollution-free fuel of the future. However, nearly all hydrogen used today is produced by means of expensive processes that require combustion of polluting fossil fuels. Moreover, storing and transporting hydrogen is extremely difficult and costly.
The new solar technology tackles these problems by creating an easily storable intermediate energy source form from metal ore, such as zinc oxide. With the help of concentrated sunlight, the ore is heated to about 1,200°C in a solar reactor in the presence of wood charcoal. The process splits the ore, releasing oxygen and creating gaseous zinc, which is then condensed to a powder. Zinc powder can later be reacted with water, yielding hydrogen, to be used as fuel, and zinc oxide, which is recycled back to zinc in the solar plant. In recent experiments, the 300-kilowatt installation produced 45 kilograms of zinc powder from zinc oxide in one hour, exceeding projected goals.
The process generates no pollution, and the resultant zinc can be easily stored and transported, and converted to hydrogen on demand. In addition, the zinc can be used directly, for example, in zinc-air batteries, which serve as efficient converters of chemical to electrical energy. Thus, the method offers a way of storing solar energy in chemical form and releasing it as needed.
The concept of splitting metal ores with the help of sunlight has been under development over the course of several years at the Weizmann Institute's Canadian Institute for the Energies and Applied Research, one of the most sophisticated solar research facilities in the world, which has a solar tower, a field of 64 mirrors and unique beam-down optics.
The process was tested originally on a scale of several kilowatts; it has been scaled up to 300 kilowatt in collaboration with the European researchers.
Weizmann scientists are currently investigating metal ores other than zinc oxide, as well as additional materials that may be used for efficient conversion of sunlight into storable energy.
The research from this press release will be presented at the ISES 2005 Solar World Congress - Bringing Water to the World, scheduled to take place during August 6-12, 2005 in Orlando, Fl US http://www.swc2005.org
Prof. Jacob Karni's research is supported by the Sussman Family Center for the Study of Environmental Sciences; the Solomon R. and Rebecca D. Baker Foundation; the Angel Faivovich Foundation for Ecological Research; Mr. Nathan Minzly, UK; the Abraham and Sonia Rochlin Foundation; Mr. and Mrs. Larry Taylor, Los Angeles, CA; Dr. and Mrs. Robert Zaitlin, Los Angeles, CA; and the Arnold Ziff Charitable Foundation.
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New Chemistry Method Uses 'Test Tubes' Far Smaller Than the Width of a Hair
Using a water droplet 1 trillion times smaller than a liter of club soda as a sort of nanoscale test tube, a University of Washington scientist is conducting chemical analysis and experimentation at unprecedented tiny scales.
The method captures a single cell, or even a small subcellular structure called an organelle, within a droplet. It then employs a powerful laser microscope to study the contents and examine chemical processes, and a laser beam is used to manipulate the cell or even just a few molecules, combining them with other molecules to form new substances.
This nanoscale "laboratory" is so minuscule that it covers just 1 percent of the width of a human hair, said Daniel Chiu, a UW associate chemistry professor who is developing the unique method.
The new approach makes it easier to get a wide range of information about a cell. Researchers typically use microscopy to see how proteins move within a cell and collect spatial information, but that provides very little biochemical information, Chiu said. Likewise, they can use large amounts of material in a test tube to understand biochemical processes, but that doesn't provide the fine detail of microscopy.
The new method, employing a process called microfluidics, allows researchers to perform chemical analysis and to study structure and form at the same time.
The tiny droplet is contained in a microfluidic device, which is far too small to be seen with the naked eye and is mounted on a platform about the size of a dime so researchers can carry it from one place to another. The device has water in one channel and oil in an adjoining channel. The target -- a cell, an organelle or just a few molecules -- is placed at the interface between the oil and water using a laser beam, so the target is encapsulated as the water droplet is formed.
Once the droplet captures its target, it is held fast while researchers use lasers to manipulate it and conduct analysis and experimentation.
Chiu presented his work today during a session of the American Chemical Society's fall meeting in Washington, D.C.
The new method allows researchers to address specific biological questions that cannot be answered by testing in large quantities in the test tube, such as how organelles within a cell differ from each other, or how different proteins are expressed within the same cell, Chiu said.
Currently Chiu is focused on continuing development of the process, essentially creating a nanoscale test tube. But he believes the process holds great promise for future chemical and biological research.
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UCSF Team Advances Probe of Neural Stem Cell-Brain Tumor Link
The public’s enthusiasm for stem cell research has focused on the potential of the cells to treat disease and traumatic injury. But UCSF researchers are working on another angle of stem cell research — one focused on illuminating disease.
Theoretically, if scientists could deduce how to prompt embryonic or adult stem cells to evolve into the various specialized cells of the body, the cells could be transplanted into patients, replacing, for example, the key brain cells destroyed in Parkinson’s disease.
But below the public radar screen is another element of stem cell research — one focused on illuminating disease. Scientists are studying the earliest stages of embryonic and adult stem cell growth in the culture dish and in animal models with the ultimate goal of identifying the genetic missteps that cause such diseases as amyotrophic lateral sclerosis (ALS), and that account for some cases of birth defects and infertility. Scientists also are conducting studies on adult stem cells to determine whether disregulated stem cells cause some cancers.
In the Aug. 25 issue of New England Journal of Medicine, a team of UCSF stem cell scientists and neurosurgeons reports on the increasing evidence from labs around the world that stem cells found in the brain — known as neural stem cells — may be the cause of the most common form of primary brain tumor. These tumors are called malignant gliomas.
Last year, the same team reported the discovery of a ribbon of neural stem cells in the human brain (Nature, Feb. 19, 2004), offering hope that the cells could someday be used to develop strategies for regenerating damaged brain tissue. But at the time, the team, including co-author Mitchel Berger, MD, professor and chairman of the UCSF Department of Neurological Surgery and director of the UCSF Brain Tumor Research Center, also noted that data suggested disregulated forms of these cells could play a role in several disease processes. These include malignant gliomas, the demyelination (or destruction of the protective coating on nerve fibers) associated with multiple sclerosis, and neurodegeneration.
In the current review article, the team examined a body of evidence that they say signals a watershed moment in the convergence of neural stem cell research and brain tumor research.
Malignant gliomas have a dismal prognosis, in part due to the lack of understanding about the cellular origin of the disease, which has thwarted scientists’ efforts to refine treatments and predict tumor behavior.
Much of the current research effort focuses on identifying where in the brain — and by what type of cell — the tumors emerge. In the 1950s, long before it was proven that stem cells existed in the adult brain, studies in animals suggested that gliomas developed in the lining of the brain’s fluid-filled cavity, known as the subventricular zone (SVZ). Rodents exposed to chemicals known to cause genetic mutations associated with gliomas developed tumors in this region. As the tumors grew, they migrated away from the area, toward the brain’s surface.
By the time gliomas are detected in humans, they generally are found in the white matter and, like those found in the rodent studies, are made up of numerous cell types, including astroyctes, oligodendrocytes and, to a lesser extent, neurons.
In the last decade, the discovery that the brain contains neural stem cells has opened up a new landscape for exploration. In humans, the cells have been found in three regions — the SVZ (the discovery in human tissue was made by the UCSF team, Nature, Feb 19, 2004), the hippocampus (deep in the back of the brain) and the subcortical white matter — a vast region underlying the cortical surface of the brain.
The cells have caught the attention of cancer researchers in part because neural stem cells and the progenitor glial cells they produce (the foot soldiers on the assembly line that leads to the creation of the brain’s three mature cell types -- neurons, astrocytes and oligodendrocytes) have many of the same properties as the cancer cells that make up tumors of the nervous system: They proliferate continuously, produce numerous cell types, and are regulated by some of the same genetic pathways active in many brain tumors. As a result, they are capable of exhibiting many of the characteristics of gliomas, says Sanai. Recently, scientists have shown that if they create certain glioma-associated genetic mutations in neural stem cells and insert them into mice, the neural stem cells begin to display the signs of glial tumor formation.
The gold standard in advancing the theory, however, says Sanai, would be to demonstrate in the culture dish that human neural stem cells could be sequentially modified to form gliomas.
A key to advancing the research at this point is examining human brain tissue, notes Sanai. The UCSF team’s investigation, he says, is being fueled in part by unusual access to this material, as UCSF Medical Center has one of the highest volumes of brain tumor patients in the world and a similarly large human brain tissue bank.
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‘Mad Cow’ Proteins Successfully Detected in Blood
Researchers at the University of Texas Medical Branch at Galveston (UTMB) have found a way to detect in blood the malformed proteins that cause “mad cow disease,” the first time such “prions” have been detected biochemically in blood.
The discovery, reported in an article in Nature Medicine Aug. 28, is expected to lead to a much more effective detection method for the infectious proteins responsible for brain-destroying disorders, such as bovine spongiform encephalopathy (BSE) in cattle and variant Creutzfeldt-Jakob disease (vCJD) in humans. The blood test would make it much easier to keep BSE-infected beef out of the human food supply, ensure that blood transfusions and organ transplants do not transmit vCJD, and give researchers their first chance to figure out how many people may be incubating the disease.
“The concentration of infectious prion protein in blood is far too small to be detected by the methods used to detect it in the brain, but we know it’s still enough to spread the disease,” said UTMB neurology professor Claudio Soto, senior author of the Nature Medicine paper. “The key to our success was developing a technique that would amplify the quantity of this protein more than 10 million-fold, raising it to a detectable level.”
Soto and the paper’s other authors, UTMB assistant professor of neurology Joaquin Castilla and research assistant Paula Saá, applied a method they call protein misfolding cyclic amplification (PMCA) to blood samples taken from 18 prion-infected hamsters that had developed clinical symptoms of prion disease. PMCA uses sound waves to vastly accelerate the process that prions use to convert normal proteins to misshapen infectious forms.
Successive rounds of PMCA led to the discovery of prions in the blood of 16 of the 18 infected hamsters. No prions were found in blood samples that were taken from 12 healthy control hamsters and subjected to the same treatment.
“Since the original publication of a paper on our PMCA technology, we’ve spent four years optimizing and automating this process to get to this point,” Soto said. “The next step, which we’re currently working on, will be detecting prions in the blood of animals before they develop clinical symptoms and applying the technology to human blood samples.”
Tests for infectious prions in cattle and human blood are badly needed. Because current tests require post-slaughter brain tissue for analysis, in the United States only cattle already showing clinical symptoms of BSE (so-called “downer cows”) are tested for the disorder. This is true even though vCJD potentially can be transmitted by animals not yet showing symptoms of the disease. (Only two cases of BSE have been found in American cows so far.) And although British BSE cases have been in decline since 1992, scientists believe the British BSE epidemic of the 1980s could have exposed millions of people in the UK and Europe to infectious prions. The extent of the vCJD epidemic is yet unknown. So far the disease has killed around 180 people worldwide, but numbers could reach thousands or even hundreds of thousands in the coming decades. Prions have also been shown to be transmissible through blood transfusions and organ transplants.
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Researchers Find Drug that Blocks Spread of Lung Cancer in Mice
Researchers at UT Southwestern Medical Center have found a compound that shows promise as a way to block the spread, or metastasis, of lung cancer.
The researchers found that the compound blocks an enzyme that is known to keep cells immortal and that is implicated in almost all human cancers. From results in mice, they determined that the compound, called GRN163L, also works rapidly and in doses that would be reasonable for therapy. It may be particularly useful after surgery or in combination with chemotherapy or radiotherapy to prevent residual cancer cells from spreading.
"We showed for the first time that this drug can work in animals," said Dr. Jerry Shay, professor of cell biology at UT Southwestern and senior author of the study, which appears in the September issue of the journal Cancer Research.
Lung cancer is the leading cause of cancer death, killing more people than breast cancer, prostate cancer and colon cancer combined, according to the American Cancer Society. Lung adenocarcinoma accounts for about 40 percent of lung cancers. Its rate is increasing worldwide, Dr. Shay said, and survival rates are poor because the disease metastasizes, usually by the time treatment begins in most cases.
The researchers designed, synthesized and tested GRN163L, which consists of 13 nucleotides, the units that make up DNA, plus a fatty section that improves the rate at which cells take it in. GRN163L specifically matches a stretch of DNA at the end of the chromosome, a segment called the telomere. Normally, as cells divide and age, telomeres become shorter and shorter. When they reach a certain length, the cells stop dividing. But the telomeres in cancerous cells stay the same length, thanks to an enzyme called telomerase.
The gene that creates telomerase is active in about 85 percent to 90 percent of tumors and in only a few noncancerous cells. Telomerase doesn't cause cancer, but it allows the cancer cells to keep dividing. It's almost a universal target for fighting cancer, Dr. Shay said, and its specificity is what makes it attractive for attack.
Telomerase works by binding to DNA and, with a protein section, keeping the chromosome from getting shorter. GRN163L apparently prevents telomerase from binding. The researchers injected human lung tumor cells into the tails of mice and found that GRN163L blocked the development of metastatic tumors over several months. The higher the dose, the fewer tumors there were.
The research was partly responsible for getting the drug into clinical trials, where it will soon be tested on humans, Dr. Shay said. The trials, recently approved by the Food and Drug Administration, are at an early stage, in which the drug is simply being tested for safety.
Future experiments on animals will involve combining GRN163L with other drugs and with radiation and therapy to see how it interacts with these other cancer treatments.
Other UT Southwestern researchers involved in the study were Drs. Gunnur Dikmen and Ginelle Gellert, former postdoctoral researchers in cell biology, Dr. Shalmica Jackson, postdoctoral researcher in cell biology, and Dr. Woodring Wright, professor of cell biology. Researchers from the Geron Corp. also participated.
The work was supported in part by the National Cancer Institute, Geron Corp., Tubitak and the Turkey Education Foundation in Turkey.
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Oxford Research Shows How the Brain Processes Words
The sound of words gets processed in a separate part of our brain from word meaning, finds Oxford research published on Wednesday, August 31 in the Journal of Neuroscience.
Neuroscientists in Oxford’s Centre for Functional Magnetic Resonance Imaging of the Brain and Oxford’s Department of Experimental Psychology found that the front part of the section of our brain known as ‘Broca’s area’ deals with word meaning, whereas the back part of Broca’s area deals with word sound.
Since the 19th century it has been clear that Broca’s area is critical for language, and modern brain imaging studies suggest that the area is involved in processing both the sound and meaning of words. However, it was previously unclear whether the region acts as a single unit or if it can be subdivided into separate areas.
Researchers used a non-invasive technique called transcranial magnetic stimulation to momentarily disrupt normal brain functioning in either the front (anterior) or back (posterior) portion of Broca’s area. Stimulating the front part selectively interfered with people’s ability to identify synonyms (words that mean the same, for example ‘dress’ and ‘frock’), suggesting that this area controls the processing of meaning. Stimulation of the back part interfered with people’s ability to identify homophones (words that sound the same, for example ‘throne’ and ‘thrown’), suggesting that this part deals with sound.
Transcranial magnetic stimulation (TMS) uses a rapidly changing electrical current within a conducting coil to create a magnetic field. When this small coil is placed against the scalp, its magnetic field disrupts the brain processing in that particular area. In effect, it allows scientists to temporarily switch off, or at least inhibit, specific areas of the brain.
Participants in the experiment were shown two words at once on a computer screen. They were asked first to decide whether or not the words were synonyms (such as ‘biscuit–cookie’; ‘couch–sofa’; ‘gift–present’). Then in another task they were asked to say whether pairs of words were homophones (such as ‘hear–here’; ‘serial–cereal’; ‘links–lynx’). When TMS was used against the anterior region they took longer on the synonyms test but their performance on the homophones test was unaffected. When it was used on the posterior region the reverse was true.
The results indicate that Broca’s area can be sub-divided into separable, but linked, anterior and posterior components. The researchers suggest that the regionally-specific effects they observed are due to differing connections with the rest of the brain. They believe that the anterior section of Broca’s area is connected with those areas of the rest of the brain associated with semantic memory, whereas the posterior region is linked to those areas of the brain associated with auditory speech processing.
