Researchers at MIT have got our brains figured out, well, at least when it comes to parsing sentences. A recent study highlighted that complex and uncommon sentences give our language-processing centers a rigorous workout, while simple sentences just don't have the same effect. This unearthed detail could further our understanding of how our brains process language, steering us towards a clearer picture of cognitive function.
The study's big reveal was that sentences with odd grammar structures or unexpected meanings tend to make the language regions in the left hemisphere of the brain, including Broca's area, work harder. Straightforward phrases, conversely barely elicited a blip on their radars, and nonsensical word salads? They barely registered. For instance, "Buy sell signals remains a particular," a sentence from the C4 language dataset, got the brain's attention, but "We were sitting on the couch" did not induce the same reaction.
Evelina Fedorenko, an Associate Professor of Neuroscience at MIT and a member of the prestigious McGovern Institute for Brain Research, led the study. "The input has to be language-like enough to engage the system," Fedorenko stated. "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," she told MIT News.
Building on this, the team put together 1,000 sentences from diverse sources like books, spoken transcripts, and websites. By observing the brain activity of participants reading these sentences through fMRI scans, and comparing it with the way an artificial language model responded, they developed a "closed-loop" system that could predict how human brains would react to new sentences based on earlier data.
Sentences with higher surprisal sparked more significant brain responses. Another contributing factor was linguistic complexity, which took into account grammar rules and sentence plausibility, meaning sentences too simplistic, or so complex they became nonsensical, didn't cut the mustard in terms of brain activation.
Looking ahead, the research team plans to expand their study to include speakers of other languages and even peek into the brain's right hemisphere to understand how it processes language. Supported by the likes of an Amazon Fellowship from the Science Hub and the National Institutes of Health, their work shines a light on the intricate dance between our brains and the myriad ways words can be woven together.
