The team focused on an area of the brain called the superior temporal gyrus, or STG.
This broad region is not just part of the hearing apparatus but one of the “higher-order” brain regions that help us make linguistic sense of the sounds we hear.
The team monitored the STG brain waves of 15 patients who were undergoing surgery for epilepsy or tumours, while playing audio of a number of different speakers reciting words and sentences.
The trick is disentangling the chaos of electrical signals that the audio brought about in the patients’ STG regions.
To do that, the team employed a computer model that helped map out which parts of the brain were firing at what rate, when different frequencies of sound were played.
With the help of that model, when patients were presented with words to think about, the team was able to guess which word the participants had chosen.
They were even able to reconstruct some of the words, turning the brain waves they saw back into sound on the basis of what the computer model suggested those waves meant.
“There’s a two-pronged nature of this work - one is the basic science of how the brain does things,” said Robert Knight of UC Berkeley, senior author of the study.
(Source: akio)
