Sentences with greater linguistic complexity are most likely to fire up a key brain language processing center, according to an MIT study that employed an artificial language network.
With help from an artificial language network, MIT neuroscientists have discovered what kind of sentences are most likely to fire up the brain's key language processing centers. The new study reveals that sentences that are more complex, either because of unusual grammar or unexpected meaning, generate stronger responses in these language processing centers. Sentences that are very straightforward barely engage these regions, and nonsensical sequences of words don't do much for them either. For example, the researchers found this brain network was most active when reading unusual sentences such as "Buy sell signals remains a particular," taken from a publicly available language dataset called C4. However, it went quiet when reading something very straightforward, such as "We were sitting on the couch." "The input has to be language-like enough to engage the system," says Evelina Fedorenko, Associate Professor of Neuroscience at MIT and a member of MIT's McGovern Institute for Brain Research. "And then within that space, if things are really easy to process, then you don't have much of a response. But if things get difficult, or surprising, if there's an unusual construction or an unusual set of words that you're maybe not very familiar with, then the network has to work harder." Fedorenko is the senior author of the study, which appears today in Nature Human Behavior. MIT graduate student Greta Tuckute is the lead author of the paper. Processing language In this study, the researchers focused on language-processing regions found in the left hemisphere of the brain, which includes Broca's area as well as other parts of the left frontal and temporal lobes of the brain. "This language network is highly selective to language, but it's been harder to actually figure out what is going on in these language regions," Tuckute says. "We wanted to discover what kinds of sentences, what kinds of linguistic input, drive the left hemisphere language network." The…