American scientists announced on Wednesday that they had discovered the way the brain hears words. The researchers say this is a major step forward in helping people who have suffered paralysis or stroke to get back to communicating with others.
According to the BBC, the technique, called functional magnetic resonance imaging, consists of placing electrodes on the brains of the individuals undergoing the study and then asking them to listen to conversations. In this way, the scientists were able to monitor cerebral blood flow, and then analyze, through a special computer, the recorded sound frequencies. Finally, they decoded the words and reconstructed which ones were being heard.
Functional magnetic resonance technology has shown promise for identifying words or ideas that someone may be thinking. By studying the blood flow patterns related to particular images, the researchers showed that such patterns can be used to guess the figures that are being thought of at the time.
Scientist Brian Pasley and his team, from the Helen Wills Institute of Neuroscience at Berkeley University of California, focused on an area of the brain called the upper temporal gyrus (STG). This wide region not only helps a part of the human hearing system, but also one of the responsible areas that help us to differentiate the sounds we hear.
By identifying how and where the brain records sounds, the researchers were able to generate a map of the words and recreate them as they were heard. The trick was to unravel the chaos of electrical signals in patients’ STG brain regions.
“When this particular area of the brain is being activated, we know that it corresponds approximately to some frequency of sound that the patient is hearing at that moment. Thus, we were able to create a map that allows us, to some extent, to use the activity of the brain to resynthesize sound by the frequencies we’re guessing, “said Pasley.
The study authors warn that the idea of translating a thought is getting better and closer to becoming a reality. In the case of brain sound research, this information could someday help scientists determine what people who cannot speak physically mean.