Japanese, Italian, Ukrainian, Swahili, Tagalog, and dozens of other spoken languages flash the same “universal language network” in the brains of native speakers. This language processing hub has been extensively studied in English speakers, but now neuroscientists have confirmed that the exact same network is activated in speakers of 45 different languages, representing 12 different language families.
“This study is very fundamental and extends some of the findings from English to a broad range of languages,” said senior author Evelina Fedorenko, associate professor of neuroscience at MIT and member of MIT’s McGovern Institute for Brain Research expression (opens in new tab).
“The hope is that now that we see that the basic properties appear to be common across languages, we can ask about possible differences between languages and language families as implemented in the Brainand we can study phenomena that don’t really exist in English,” said Fedorenko. For example, speakers of “tonal” languages like Mandarin convey different word meanings through shifts in their tone or pitch; English is not a tonal language so it may be processed slightly differently in the brain.
The study published Monday (July 18) in the journal nature neuroscience (opens in new tab), involved two native speakers of each language who underwent brain scans while performing various cognitive tasks. Specifically, the team scanned the participants’ brains using a technique called functional magnetic resonance imaging (fMRI), which tracks oxygen flow blood through the brain. Active brain cells require more energy and oxygen, so fMRI provides an indirect measure of brain cell activity.
Related: ‘Secret code’ behind key type of memory revealed in new brain scans
During the fMRI scans, participants listened to passages from Lewis Carroll’s “Alice in Wonderland” (better known as “Alice in Wonderland”) read aloud in their native language. In theory, all listeners should use the same language network to process stories read in their native language, the researchers hypothesize.
Participants also listened to several recordings that, in theory, would not activate this voice network. For example, they listened to recordings in which the native speaker’s words were distorted beyond recognition and passages read by a speaker of a foreign language. In addition to completing these language-related tests, participants were asked to solve math problems and perform memory tasks; Like the incoherent recordings, neither the math nor the memory tests are intended to activate the language network, the team hypothesized.
“Language spaces [of the brain] are selective,” said first author Saima Malik-Moraleda, a doctoral student in the Speech and Hearing Bioscience and Technology program at Harvard University, in the statement. “You shouldn’t react during other tasks, such as a spatial working memory task, and that’s what we found in the speakers of 45 languages we tested.”
In native English speakers, the brain areas that are activated during language processing appear mainly in the left hemisphere, mainly in the frontal lobe, which is located behind the forehead, and the temporal lobe, which is located behind the ear. By creating “maps” of the brain activity of all their subjects, the researchers showed that the same brain areas were activated regardless of the language being heard.
The team observed slight differences in brain activity between individual speakers of different languages. However, the same small degree of variation has also been observed among native English speakers.
These results aren’t necessarily surprising, but they lay a crucial foundation for future studies, the team wrote in their report. “Although we expected it, this demonstration provides an essential basis for future systematic, in-depth, and finer-grained cross-language comparisons,” they wrote.
Originally published on Live Science.