The researchers analyzed the brain waves of 29 volunteer patients who underwent epilepsy surgery. During the procedure, electrodes were stuck directly to the surface of their brains while the same three minutes of the famous song played in the operating room and their brain activity was measured. They were instructed to listen attentively. This provided electroencephalographic (iEEG) measurements from a total of 2,668 electrodes, at various locations in the brain.
The researchers chose the rock song because it is very complex with different instruments, strings, and rhythms. From these brain measurements, they trained artificially intelligent computer models to analyze neural patterns in patients’ brains. The electrodes monitored activity in the patients’ auditory cortex, an area of the brain that processes all aspects of the sound we perceive. By comparing brain activity to the sounds in the song, the researchers discovered neural patterns associated not only with specific words, but also with pitch, rhythm, stress, and intonation.
Because the computer model was able to recognize patterns of brain activity that corresponded to certain musical properties, the researchers were eventually able to reconstruct the brain’s version of the legendary song in what is called a spectrogram, a graphical representation of sound that includes frequency and length. And the size.
This achievement opens another door to exploring and understanding the complexity of the human brain, and could mean a lot to people who cannot speak well. In the future, this technology could lead to better speech computers that can help patients express more emotions.
