Thanks to Pink Floyd, scientists have made a new breakthrough, adding “another brick in the wall of our understanding of music processing in the human brain.”
New research published Tuesday in the journal PLoS Biology showed that scientists can train a computer to recreate a song based solely on the brain activity of someone listening to music.
Scientists were able to reconstruct a passable cover of Pink Floyd’s 1979 song, “Another Brick in the Wall (Part 1).”
“It’s a wonderful result,” co-author Robert T. Knight, a neurologist and UC Berkeley professor of psychology at the Helen Wills Neuroscience Institute, said in a media release. “One of the things for me about music is it has prosody and emotional content.”
This is the first time a recognizable song has been interpreted from nothing but recordings of electrical brain activity, giving hope that the new understanding of how people comprehend sound could eventually help improve devices for those with speech difficulties.
Neuroscientists at the University of California, Berkeley, analyzed recordings from electrodes of 29 patients undergoing surgery for epilepsy as they listened to the Pink Floyd song.
They were able to identify thoughts connected to the tone, rhythm, harmony and words of the song by looking at the electrical activity of brain regions and comparing the brain signals with the song.
Pink Floyd’s lyrics, “All in all it was just a brick in the wall,” is audible in the reconstructed version of the song, with the rhythm unscathed.
They used intracranial electroencephalography (iEEG) — when a surgeon records electrical activity from the brain by placing electrodes inside the skull, according to Johns Hopkins Medicine — which can only record from the surface of the brain, as close to the auditory centers as possible.
“Noninvasive techniques are just not accurate enough today. Let’s hope, for patients, that in the future we could, from just electrodes placed outside on the skull, read activity from deeper regions of the brain with a good signal quality. But we are far from there,” co-author Ludovic Bellier said.
A region called the superior temporal gyrus was able to process the rhythm of the guitar in the song, while signals from the right hemisphere of the brain were more critical for processing music than the left.
These recordings from electrodes on the brain surface could be beneficial to reproducing the musicality of speech for people who have trouble communicating, whether from stroke or paralysis.
“As this whole field of brain machine interfaces progresses, this gives you a way to add musicality to future brain implants for people who need it, someone who’s got ALS or some other disabling neurological or developmental disorder compromising speech output,” Knight explained.
“It gives you an ability to decode not only the linguistic content, but some of the prosodic content of speech, some of the affect. I think that’s what we’ve really begun to crack the code on.”
