Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers find a neural signature of bilingualism

19.10.2006
The team uses infrared light to study the brain

Dartmouth researchers have found areas in the brain that indicate bilingualism. The finding sheds new light on decades of debate about how the human brain's language centers may actually be enhanced when faced with two or more languages as opposed to only one. The study was presented at the Society for Neuroscience's annual meeting on October 14-18 in Atlanta, Ga.

The authors from left to right: Ioulia Kovelman, Mark Shalinsky, Laura-Ann Petitto; seated: Melody Berens. (Photo by Joseph Mehling '69)

The researchers used an optical imaging technology called Near Infrared Spectroscopy (or NIRS) as a new "microscope" into the human brain's higher cognitive capacities, and they are among the first to take advantage of this technology in this way. NIRS has been used in the detection of, for example, breast tumors and heart blood flow. The Dartmouth team used NIRS to measure changes in the brain's oxygen levels while people performed specific language and cognitive tasks.

Authors of the study are Mark Shalinsky, former post-doctoral fellow at Dartmouth now a research fellow at Massachusetts General Hospital; Ioulia Kovelman, formerly a Dartmouth graduate student currently a post-doctoral fellow at MIT; Melody Berens, currently a post-doctoral fellow at Dartmouth; and Laura-Ann Petitto, the study's senior scientific director, and professor and chair of the Department of Education at Dartmouth.

"NIRS provides much the same information as functional magnetic resonance imaging or 'fMRI,' but has several advantages over fMRI," says Shalinsky, the study's electro-neurophysiologist who created the analysis programs to use NIRS technology in this new way. NIRS technology is quiet, small and portable. It's only about the size of a desktop computer. It's child friendly, and it tolerates a participant's body movements, which makes it ideal for studying language where participants move their mouths to speak."

The NIRS showed similar increased brain activity across all people—monolinguals and bilinguals—in the brain's classic left-hemisphere language regions when they were speaking in only one language (that is, in "monolingual mode"), involving the left Broca's area and left dorsolateral prefrontal cortex (DLPFC), which are brain areas key to language and verbal working memory, respectively.

Close up view of the NIRS equipment. (Photo by Joseph Mehling '69)
When bilinguals were simultaneously processing each of their two languages and rapidly switching between them (that is, in "bilingual mode"), they showed an increase in brain activity in both the left and the right hemisphere Broca's area, with greater activation in the right equivalent of Broca's area and the right DLPFC. This finding emerged as the key indicator of the brain's bilingual signature.

The researchers examined 20 people ranging from 18 to 30 years old (average age was 21.1 years). Ten participants were monolingual (who spoke only English), and ten were bilingual (who spoke both English and Spanish from around birth). Language processing tasks were given to monolingual people speaking their one language while undergoing NIRS brain recordings. The monolingual speakers' behavioral and brain activity were then compared to the bilingual speakers' behavioral and brain activity while performing identical language processing tasks in "monolingual mode" (that is, in Spanish, and in English) or in "bilingual mode" (that is, when simultaneously processing and rapidly switching between their two languages). The Dartmouth team used the Hitachi ETG-4000 NIRS system.

"For decades, people have wondered whether the brains of bilingual people are different from monolinguals. People also worry that the brains of bilingual children are somehow negatively impacted by early experience with two languages," explains Petitto, who also holds the John Wentworth Endowed Chair in the Social Sciences. "The present findings are significant because they show that the brains of bilinguals and monolinguals are similar, and both process their individual languages in fundamentally similar ways. The one fascinating exception is that bilinguals appear to engage more of the neural landscape available for language processing than monolinguals, which is a very good thing."

The team proposes that bilingual language processing provides a new window into the extent of what nature's neural architecture for language processing could be, if only we used it. Petitto adds, "The irony is that we may find it is the monolingual that is not taking full advantage of the neural landscape for language and cognitive processing than nature could have potentially made available."

She says that this research advances the path for using NIRS brain imaging technology both to understand the neural underpinnings of all human language and especially to discover the secrets of the bilingual brain.

This research is funded by grants to Petitto from the National Institutes of Health and the Dana Foundation.

Sue Knapp | EurekAlert!
Further information:
http://www.Dartmouth.edu

More articles from Studies and Analyses:

nachricht Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>