Philosophers have long argued about the purpose of language. Plato believed it was essential for thinking. Thought “is a silent inner conversation of the soul with itself,” he wrote.
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Many modern scholars have put forward similar views. In the 1960s, Noam Chomsky, a linguist at the Massachusetts Institute of Technology (MIT), argued that we use language for reasoning and other forms of thinking. “If there is a serious deficit of language, there will be a serious deficit of thinking,” he wrote.
As a student, Evelina Fedorenko took Chomsky’s class and listened to him describe his theory. But she was baffled by the lack of evidence. “A lot of the things he said were just stated as if they were facts — truth,” she said.
Fedorenko ended up as a cognitive neuroscientist at MIT, using brain scans to investigate how the brain produces language. And after 15 years, her research has led her to a surprising conclusion: we don’t need language to think.
When this work began in 2009, studies had found that the same brain regions needed for language were also active when people were reasoning or performing math.
Fedorenko used more powerful equipment and performed more tests on each volunteer. That gave his team enough data from each person to create a detailed picture of an individual brain.
The scientists then identified the brain circuits that were involved in language tasks, such as following grammatical rules. The volunteers read nonsense words, followed by real sentences. Certain brain regions were activated only when the volunteers processed real language.
Each volunteer had a language network — a constellation of regions that activate during language tasks. The researchers scanned the same people as they engaged in different types of thinking, such as solving a puzzle. “Other brain regions work very hard when you engage in all these forms of thinking,” Fedorenko said. But the language networks remained silent. “It became clear that none of those things seem to involve the language circuits,” he said.
In a paper published in Nature, Fedorenko’s team argued that studies of people with brain injuries point to the same conclusion.
Brain damage can wipe out the language network, leaving people struggling to process words and grammar, a condition known as aphasia. But in experiments, people with aphasia can look at two numbers — say, 123 and 321 — and recognize that, using the same pattern, 456 must be followed by 654.
If language is not essential to thought, then what is it for?
Communication, the team argues. Chomsky and others have rejected that idea, pointing to the ambiguity of words and the difficulty of expressing our intuitions out loud. “The system is not well designed in many functional respects,” Chomsky once said.
But large studies have suggested that languages have become optimized to transfer information clearly.
In one study, researchers found that frequently used words are shorter, making languages easier to learn and speeding up the flow of information. In another study, researchers studying 37 languages found that grammatical rules move words closer together so that their combined meaning is easier to understand.
Guy Dove, a philosopher at the University of Louisville in Kentucky, said Fedorenko’s team went too far in banishing language from thought — especially complex thought.
“When we think about democracy, we could try conversations about democracy,” he said. “Language is not needed to have thoughts, but it can give them substance.”
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