How the brain builds sentences, neuron by neuron

Neurons in the brain (shown here) divvy up the task of constructing different aspects of language. Credit: Ted Kinsman/Science Photo Library In the fraction of a second before a person speaks, their brain weaves together complex grammar, precise vocabulary and the underlying meaning of the language. Now, researchers have tracked the electrical crackle of individual brain cells in real time during unscripted conversations, capturing how sentences are built before a single word is spoken. By observing these neurons in a region of the human brain called the frontotemporal cortex, scientists have discovered that individual brain cells act as specialized linguistic building blocks. “We used to think language was this diffuse, whole-network phenomenon,” says Ziv Williams, a neurosurgeon at Massachusetts General Hospital (MGH) in Boston and co-author of the study. “But it turns out you have specific neurons that only care if a word is a noun, or only care if a phrase is ending.” The work was published today in Nature 1 . On the map To capture this activity, Williams and his colleagues used electrodes that were temporarily implanted in people with epilepsy to monitor their seizures. Because these participants were awake and speaking freely, the team could observe how the brain operated as they spoke. …