Ultra-detailed brain map shows neurons that encode words’ meaning

For the first time, individual brain cells have been seen to respond to the essence of words. Researchers recorded the activity of around 300 neurons each in 10 people who had electrodes implanted in their brains to manage epilepsy. Only a few neurons fired for each word when the participants listened to short sentences. Words that fell into similar categories — actions, food or animals — as well as words that could be associated — such as ‘duck’ and ‘egg’ — triggered similar brain activity. To an extent, the researchers could determine what people were hearing by watching their neurons fire.