Something extraordinary happens in your brain when you hear your favorite song. A team of researchers at MIT has discovered that the brain has a population of neurons responsive to singing. The unique combination of voice and music—but not other kinds of speech or solely instrumental music—stimulates an overwhelming response from these neurons.
Beginning with a project in 2015, former postdoc Sam Norman-Haignere and his senior authors of the study set out to examine neurons in the auditory cortex that specifically respond to music. The team used functional magnetic resonance imaging (fMRI) to locate these neurons in the initial study. All participants in the initial study listened to 165 different sounds, ranging from music to a dog barking to general speech. From this study, the team identified six different neural populations, each of which responded to the sounds in their own way (Norman-Haignere et al., 2015). This finding intrigued the researchers and led them to further investigate the purposes of these neural populations.
In the present study, the researchers wanted to obtain higher-resolution information on the electrical activity in the brain using electrocorticography (ECoG). ECoG is an invasive procedure, as electrodes are placed inside the skull. Because surgery was necessary, only 15 participants were available to participate in the study over several years.
In the same way as the 2015 study, these participants also listened to the original 165 sounds. Surgeons chose where to put the electrodes in the participants’ brains, so some auditory cortex response information was not collected due to differing electrode placement. However, most participants had active responses, and the researchers were able to determine the neural population associated with each individual electrode. From there, the researchers came across the novel and specific neuron population that responded only to singing. These neurons had little to no response for speech or instrumental music-only sounds (Norman-Haignere et al., 2022). But when participants heard singing music, these neurons lit up, and investigators wondered if they could narrow down the location of the singing-specific neurons.
After this discovery, the researchers created a mathematical model to further localize the singing-specific neuron regions in the brain. They did this by combining data from the fMRI study and the ECoG study. The researchers determined that a small spot on the top of the temporal lobe was responsible for the song-specific responses (Norman-Haignere et al., 2022). This region is also near the regions that process language and music. The research team discussed how these song-specific neuron populations may be connecting the relationship between words and perceived pitch, or something similar. So when your favorite artist’s song comes on the radio, your brain is making the connection between that tune you enjoy and the voice you love.
Understanding how these brain regions develop is important for understanding sound conductance—or how sound is processed in the brain—as well as neural behavior in response to singing. These researchers are now working with Dr. Rebecca Saxe—a pediatrician, neurologist, and expert in music and the brain—to investigate music-selective areas in infants. Hopefully, this team will be able to narrow down more specific information about the development of singing-specific brain regions and how this development influences our interests, interpretations, and enjoyment of music.
About the Author
Bailey Salimes is a senior at Boston University concentrating in Neuroscience with a secondary in Psychology.
References
Norman-Haignere, S.V., Feather, J., Boebinger, D., Brunner, P., Ritaccio, A., McDermott, J.H., Schalk, G., & Kanwisher, N. (2022). A neural population selective for song in human auditory cortex. Current Biology, 32(7), 1470-1484. https://doi.org/10.1016/j.cub.2022.01.069
Norman-Haignere, S.V., Kanwisher, N.G., & McDermott, J.H. (2015). Distinct cortical pathways for music and speech revealed by hypothesis-free voxel decomposition. Neuron, 88(6), 1281-1296. https://doi.org/10.1016/j.neuron.2015.11.035
Trafton, A. (2022, February 22). Singing in the brain. MIT News, Massachusetts Institute of Technology. Retrieved March 7, 2022, from https://news.mit.edu/2022/singing-neurons-0222.
Beginning with a project in 2015, former postdoc Sam Norman-Haignere and his senior authors of the study set out to examine neurons in the auditory cortex that specifically respond to music. The team used functional magnetic resonance imaging (fMRI) to locate these neurons in the initial study. All participants in the initial study listened to 165 different sounds, ranging from music to a dog barking to general speech. From this study, the team identified six different neural populations, each of which responded to the sounds in their own way (Norman-Haignere et al., 2015). This finding intrigued the researchers and led them to further investigate the purposes of these neural populations.
In the present study, the researchers wanted to obtain higher-resolution information on the electrical activity in the brain using electrocorticography (ECoG). ECoG is an invasive procedure, as electrodes are placed inside the skull. Because surgery was necessary, only 15 participants were available to participate in the study over several years.
In the same way as the 2015 study, these participants also listened to the original 165 sounds. Surgeons chose where to put the electrodes in the participants’ brains, so some auditory cortex response information was not collected due to differing electrode placement. However, most participants had active responses, and the researchers were able to determine the neural population associated with each individual electrode. From there, the researchers came across the novel and specific neuron population that responded only to singing. These neurons had little to no response for speech or instrumental music-only sounds (Norman-Haignere et al., 2022). But when participants heard singing music, these neurons lit up, and investigators wondered if they could narrow down the location of the singing-specific neurons.
After this discovery, the researchers created a mathematical model to further localize the singing-specific neuron regions in the brain. They did this by combining data from the fMRI study and the ECoG study. The researchers determined that a small spot on the top of the temporal lobe was responsible for the song-specific responses (Norman-Haignere et al., 2022). This region is also near the regions that process language and music. The research team discussed how these song-specific neuron populations may be connecting the relationship between words and perceived pitch, or something similar. So when your favorite artist’s song comes on the radio, your brain is making the connection between that tune you enjoy and the voice you love.
Understanding how these brain regions develop is important for understanding sound conductance—or how sound is processed in the brain—as well as neural behavior in response to singing. These researchers are now working with Dr. Rebecca Saxe—a pediatrician, neurologist, and expert in music and the brain—to investigate music-selective areas in infants. Hopefully, this team will be able to narrow down more specific information about the development of singing-specific brain regions and how this development influences our interests, interpretations, and enjoyment of music.
About the Author
Bailey Salimes is a senior at Boston University concentrating in Neuroscience with a secondary in Psychology.
References
Norman-Haignere, S.V., Feather, J., Boebinger, D., Brunner, P., Ritaccio, A., McDermott, J.H., Schalk, G., & Kanwisher, N. (2022). A neural population selective for song in human auditory cortex. Current Biology, 32(7), 1470-1484. https://doi.org/10.1016/j.cub.2022.01.069
Norman-Haignere, S.V., Kanwisher, N.G., & McDermott, J.H. (2015). Distinct cortical pathways for music and speech revealed by hypothesis-free voxel decomposition. Neuron, 88(6), 1281-1296. https://doi.org/10.1016/j.neuron.2015.11.035
Trafton, A. (2022, February 22). Singing in the brain. MIT News, Massachusetts Institute of Technology. Retrieved March 7, 2022, from https://news.mit.edu/2022/singing-neurons-0222.
