UCSF researchers led by neurosurgeon Edward Chang, MD, present a new spatial map for how the human brain processes melody.
By recording from high-density electrodes on the surface of the auditory cortex of participants listening to music, the researchers found that different features of melody are simultaneously processed by different neural populations.
Some populations respond to the pitch of the note or the change in pitch from one note to the next, and these are the same populations that encode those features of human speech.
But other populations are specifically tuned to a feature known as melodic expectation (the term for what the brain expects to hear based on previous notes). These populations are not activated while the brain is processing speech and are unique to processing melody.
“The auditory cortex isn’t just looking for notes, it’s also processing the statistical context of prior notes in which we’re hearing each new note,” Chang said. “That context is critical to how we hear the melody overall. This low-level processing of individual notes and high-level abstract contextual processing is happening simultaneously, side-by-side in parallel when we are listening to music.”
Music-selective neurons were spatially intermixed across the auditory cortex with other neuronal populations, challenging previous studies suggesting there might be a region of the brain specifically dedicated to processing music.
Reference:
Narayan Sankaran, Matthew K. Leonard, Frederic Theunissen and Edward F. Chang. Encoding of melody in the human auditory cortex. Science Advances. February 16, 2024. doi: 10.1126/sciadv.adk0010
26 сен 2024
